├── .gitignore ├── CMakeLists.txt ├── COPYING ├── COPYING.LESSER ├── docs └── index.md ├── mkdocs.yml ├── modules └── FindMaya.cmake ├── readme.md └── src ├── apply_callback_command.cpp ├── apply_callback_command.h ├── callback_node.cpp ├── callback_node.h ├── plugin_main.cpp └── plugin_main.h /.gitignore: -------------------------------------------------------------------------------- 1 | ## Ignore Visual Studio temporary files, build results, and 2 | ## files generated by popular Visual Studio add-ons. 3 | 4 | # User-specific files 5 | *.suo 6 | *.user 7 | *.userosscache 8 | *.sln.docstates 9 | 10 | # User-specific files (MonoDevelop/Xamarin Studio) 11 | *.userprefs 12 | 13 | # Build results 14 | [Dd]ebug/ 15 | [Dd]ebugPublic/ 16 | [Rr]elease/ 17 | [Rr]eleases/ 18 | x64/ 19 | x86/ 20 | bld/ 21 | [Bb]in/ 22 | [Oo]bj/ 23 | [Ll]og/ 24 | install/ 25 | 26 | # Visual Studio 2015 cache/options directory 27 | .vs/ 28 | # Uncomment if you have tasks that create the project's static files in wwwroot 29 | #wwwroot/ 30 | 31 | # MSTest test Results 32 | [Tt]est[Rr]esult*/ 33 | [Bb]uild[Ll]og.* 34 | 35 | # NUNIT 36 | *.VisualState.xml 37 | TestResult.xml 38 | 39 | # Build Results of an ATL Project 40 | [Dd]ebugPS/ 41 | [Rr]eleasePS/ 42 | dlldata.c 43 | 44 | # DNX 45 | project.lock.json 46 | project.fragment.lock.json 47 | artifacts/ 48 | Properties/launchSettings.json 49 | 50 | *_i.c 51 | *_p.c 52 | *_i.h 53 | *.ilk 54 | *.meta 55 | *.obj 56 | *.pch 57 | *.pdb 58 | *.pgc 59 | *.pgd 60 | *.rsp 61 | *.sbr 62 | *.tlb 63 | *.tli 64 | *.tlh 65 | *.tmp 66 | *.tmp_proj 67 | *.log 68 | *.vspscc 69 | *.vssscc 70 | .builds 71 | *.pidb 72 | *.svclog 73 | *.scc 74 | 75 | # Chutzpah Test files 76 | _Chutzpah* 77 | 78 | # Visual C++ cache files 79 | ipch/ 80 | *.aps 81 | *.ncb 82 | *.opendb 83 | *.opensdf 84 | *.sdf 85 | *.cachefile 86 | *.VC.db 87 | *.VC.VC.opendb 88 | 89 | # Visual Studio profiler 90 | *.psess 91 | *.vsp 92 | *.vspx 93 | *.sap 94 | 95 | # TFS 2012 Local Workspace 96 | $tf/ 97 | 98 | # Guidance Automation Toolkit 99 | *.gpState 100 | 101 | # ReSharper is a .NET coding add-in 102 | _ReSharper*/ 103 | *.[Rr]e[Ss]harper 104 | *.DotSettings.user 105 | 106 | # JustCode is a .NET coding add-in 107 | .JustCode 108 | 109 | # TeamCity is a build add-in 110 | _TeamCity* 111 | 112 | # DotCover is a Code Coverage Tool 113 | *.dotCover 114 | 115 | # Visual Studio code coverage results 116 | *.coverage 117 | *.coveragexml 118 | 119 | # NCrunch 120 | _NCrunch_* 121 | .*crunch*.local.xml 122 | nCrunchTemp_* 123 | 124 | # MightyMoose 125 | *.mm.* 126 | AutoTest.Net/ 127 | 128 | # Web workbench (sass) 129 | .sass-cache/ 130 | 131 | # Installshield output folder 132 | [Ee]xpress/ 133 | 134 | # DocProject is a documentation generator add-in 135 | DocProject/buildhelp/ 136 | DocProject/Help/*.HxT 137 | DocProject/Help/*.HxC 138 | DocProject/Help/*.hhc 139 | DocProject/Help/*.hhk 140 | DocProject/Help/*.hhp 141 | DocProject/Help/Html2 142 | DocProject/Help/html 143 | 144 | # Click-Once directory 145 | publish/ 146 | 147 | # Publish Web Output 148 | *.[Pp]ublish.xml 149 | *.azurePubxml 150 | # TODO: Comment the next line if you want to checkin your web deploy settings 151 | # but database connection strings (with potential passwords) will be unencrypted 152 | *.pubxml 153 | *.publishproj 154 | 155 | # Microsoft Azure Web App publish settings. Comment the next line if you want to 156 | # checkin your Azure Web App publish settings, but sensitive information contained 157 | # in these scripts will be unencrypted 158 | PublishScripts/ 159 | 160 | # NuGet Packages 161 | *.nupkg 162 | # The packages folder can be ignored because of Package Restore 163 | **/packages/* 164 | # except build/, which is used as an MSBuild target. 165 | !**/packages/build/ 166 | # Uncomment if necessary however generally it will be regenerated when needed 167 | #!**/packages/repositories.config 168 | # NuGet v3's project.json files produces more ignoreable files 169 | *.nuget.props 170 | *.nuget.targets 171 | 172 | # Microsoft Azure Build Output 173 | csx/ 174 | *.build.csdef 175 | 176 | # Microsoft Azure Emulator 177 | ecf/ 178 | rcf/ 179 | 180 | # Windows Store app package directories and files 181 | AppPackages/ 182 | BundleArtifacts/ 183 | Package.StoreAssociation.xml 184 | _pkginfo.txt 185 | 186 | # Visual Studio cache files 187 | # files ending in .cache can be ignored 188 | *.[Cc]ache 189 | # but keep track of directories ending in .cache 190 | !*.[Cc]ache/ 191 | 192 | # Others 193 | ClientBin/ 194 | ~$* 195 | *~ 196 | *.dbmdl 197 | *.dbproj.schemaview 198 | *.jfm 199 | *.pfx 200 | *.publishsettings 201 | node_modules/ 202 | orleans.codegen.cs 203 | 204 | # Since there are multiple workflows, uncomment next line to ignore bower_components 205 | # (https://github.com/github/gitignore/pull/1529#issuecomment-104372622) 206 | #bower_components/ 207 | 208 | # RIA/Silverlight projects 209 | Generated_Code/ 210 | 211 | # Backup & report files from converting an old project file 212 | # to a newer Visual Studio version. Backup files are not needed, 213 | # because we have git ;-) 214 | _UpgradeReport_Files/ 215 | Backup*/ 216 | UpgradeLog*.XML 217 | UpgradeLog*.htm 218 | 219 | # SQL Server files 220 | *.mdf 221 | *.ldf 222 | 223 | # Business Intelligence projects 224 | *.rdl.data 225 | *.bim.layout 226 | *.bim_*.settings 227 | 228 | # Microsoft Fakes 229 | FakesAssemblies/ 230 | 231 | # GhostDoc plugin setting file 232 | *.GhostDoc.xml 233 | 234 | # Node.js Tools for Visual Studio 235 | .ntvs_analysis.dat 236 | 237 | # Visual Studio 6 build log 238 | *.plg 239 | 240 | # Visual Studio 6 workspace options file 241 | *.opt 242 | 243 | # Visual Studio 6 auto-generated workspace file (contains which files were open etc.) 244 | *.vbw 245 | 246 | # Visual Studio LightSwitch build output 247 | **/*.HTMLClient/GeneratedArtifacts 248 | **/*.DesktopClient/GeneratedArtifacts 249 | **/*.DesktopClient/ModelManifest.xml 250 | **/*.Server/GeneratedArtifacts 251 | **/*.Server/ModelManifest.xml 252 | _Pvt_Extensions 253 | 254 | # Paket dependency manager 255 | .paket/paket.exe 256 | paket-files/ 257 | 258 | # FAKE - F# Make 259 | .fake/ 260 | 261 | # JetBrains Rider 262 | .idea/ 263 | *.sln.iml 264 | 265 | # CodeRush 266 | .cr/ 267 | 268 | # Python Tools for Visual Studio (PTVS) 269 | __pycache__/ 270 | *.pyc 271 | 272 | # Cake - Uncomment if you are using it 273 | # tools/ 274 | 275 | # Prerequisites 276 | *.d 277 | 278 | # Compiled Object files 279 | *.slo 280 | *.lo 281 | *.o 282 | *.obj 283 | 284 | # Precompiled Headers 285 | *.gch 286 | *.pch 287 | 288 | # Compiled Dynamic libraries 289 | *.so 290 | *.dylib 291 | *.dll 292 | 293 | # Compiled Static libraries 294 | *.lai 295 | *.la 296 | *.a 297 | *.lib 298 | 299 | # Executables 300 | *.exe 301 | *.out 302 | *.app 303 | 304 | # Byte-compiled / optimized / DLL files 305 | __pycache__/ 306 | *.py[cod] 307 | 308 | # C extensions 309 | *.so 310 | 311 | # Distribution / packaging 312 | .Python 313 | env/ 314 | build/ 315 | develop-eggs/ 316 | dist/ 317 | downloads/ 318 | eggs/ 319 | parts/ 320 | sdist/ 321 | var/ 322 | *.egg-info/ 323 | .installed.cfg 324 | *.egg 325 | 326 | # PyInstaller 327 | # Usually these files are written by a python script from a template 328 | # before PyInstaller builds the exe, so as to inject date/other infos into it. 329 | *.manifest 330 | *.spec 331 | 332 | # Installer logs 333 | pip-log.txt 334 | pip-delete-this-directory.txt 335 | 336 | # Unit test / coverage reports 337 | htmlcov/ 338 | .tox/ 339 | .coverage 340 | .cache 341 | nosetests.xml 342 | coverage.xml 343 | 344 | # Translations 345 | *.mo 346 | *.pot 347 | 348 | # Django stuff: 349 | *.log 350 | 351 | # Sphinx documentation 352 | docs/build/ 353 | 354 | # PyBuilder 355 | target/ 356 | 357 | # PyCharm 358 | .idea/ 359 | 360 | # Ignore virtualenvs 361 | virtualenv/ 362 | venv/ 363 | 364 | # Ignore generated files 365 | scripts/extras/om2_completions/ 366 | 367 | # Ignore Mac OSX Cache files 368 | *.DS_Store 369 | 370 | # Ignore tags files for IDEs 371 | GPATH 372 | GRTAGS 373 | GTAGS 374 | 375 | # Ignore Emacs specific IDE files 376 | *.el 377 | *.clang_complete 378 | 379 | # mkdocs 380 | site/ 381 | -------------------------------------------------------------------------------- /CMakeLists.txt: -------------------------------------------------------------------------------- 1 | # CMake 2.8.11 and above required for linking to qtmain.lib library on Windows 2 | # CMake 2.8.12 and above required for MACOSX_RPATH property 3 | cmake_minimum_required(VERSION 2.8.12) 4 | set(PROJECT_NAME "callbackNodeExample") 5 | # TODO: (sonictk) Make tests 6 | # set(TEST_EXECUTABLE_NAME "tests_${PROJECT_NAME}") 7 | 8 | if(APPLE) 9 | message(STATUS "Setting MacOSX SDK...") 10 | set(CMAKE_OSX_SYSROOT "/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk") 11 | endif(APPLE) 12 | 13 | project(${PROJECT_NAME}) 14 | 15 | # Attempt to find existing installation of Maya and define variables 16 | set(CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/modules) 17 | find_package(Maya REQUIRED) 18 | 19 | # Add include search paths 20 | include_directories( 21 | ${MAYA_INCLUDE_DIR} 22 | ${PROJECT_SOURCE_DIR}/include 23 | ) 24 | message(STATUS "Including Maya headers from: ${MAYA_INCLUDE_DIR}") 25 | message(STATUS "Including project headers from: ${PROJECT_SOURCE_DIR}/include") 26 | 27 | if(APPLE) 28 | set(MAYA_FRAMEWORK_DIR "${MAYA_LOCATION}/Maya.app/Contents/Frameworks") 29 | message(STATUS "Setting OSX Framework path to: ${MAYA_FRAMEWORK_DIR}") 30 | set(CMAKE_MACOSX_RPATH TRUE) 31 | set(CMAKE_FIND_FRAMEWORK FIRST) 32 | set(CMAKE_FRAMEWORK_PATH "${MAYA_FRAMEWORK_DIR}") 33 | endif(APPLE) 34 | 35 | # Allow for multithreaded builds on Linux via flag 36 | set(MAKE_MULTITHREADED_BUILD_THREADS 8 CACHE STRING "Number of threads to use when building with GNU Make") 37 | if(MAKE_MULTITHREADED_BUILD_THREADS) 38 | if(${CMAKE_GENERATOR} MATCHES "Unix Makefiles") 39 | message(STATUS "Setting number of threads to use for building: ${MAKE_MULTITHREADED_BUILD_THREADS}") 40 | set(CMAKE_MAKE_PROGRAM "${CMAKE_MAKE_PROGRAM} -j${MAKE_MULTITHREADED_BUILD_THREADS}") 41 | endif() 42 | endif(MAKE_MULTITHREADED_BUILD_THREADS) 43 | 44 | # Set compiler flags for each platform 45 | if(CMAKE_CXX_COMPILER_ID MATCHES "Clang") 46 | message(STATUS "Setting compiler options for Clang...") 47 | # Using Clang 48 | set(CMAKE_CXX_FLAGS "-stdlib=libstdc++ \ 49 | -std=c++0x \ 50 | -fno-gnu-keywords \ 51 | -fpascal-strings \ 52 | -pthread \ 53 | -O3 \ 54 | -dynamic") 55 | set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS} -g -O0 -gdwarf-4 -gmodules") 56 | set(CMAKE_EXE_LINKER_FLAGS "-stdlib=libstdc++ \ 57 | -std=c++0x \ 58 | -fno-gnu-keywords \ 59 | -fpascal-strings \ 60 | -O3 \ 61 | -Wl, \ 62 | -headerpad_max_install_names \ 63 | -dynamic") 64 | 65 | elseif(CMAKE_CXX_COMPILER_ID STREQUAL "GNU") 66 | message(STATUS "Setting compiler options for GCC...") 67 | # using GCC on Linux 68 | set(CMAKE_C_FLAGS "-DBits64_ \ 69 | -m64 \ 70 | -DUNIX \ 71 | -D_BOOL \ 72 | -DLINUX \ 73 | -DFUNCPROTO \ 74 | -D_GNU_SOURCE \ 75 | -DLINUX_64 \ 76 | -fPIC \ 77 | -fno-strict-aliasing \ 78 | -DREQUIRE_IOSTREAM \ 79 | -O3 \ 80 | -Wall \ 81 | -Wno-multichar \ 82 | -Wno-comment \ 83 | -Wno-sign-compare \ 84 | -funsigned-char \ 85 | -pthread") 86 | set(CMAKE_CXX_FLAGS "${CMAKE_C_FLAGS} \ 87 | -Wno-deprecated \ 88 | -Wno-reorder \ 89 | -ftemplate-depth-25 \ 90 | -fno-gnu-keywords") 91 | set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS} -ggdb -O0") 92 | 93 | elseif(MSVC) 94 | message(STATUS "Setting compiler options for MSVC...") 95 | # using Visual Studio C++ 96 | set(CMAKE_CXX_FLAGS "/MP /GR /GS /W3 /Gy /Zc:wchar_t /Zc:forScope /O2 /Ob1 /fp:precise /GF /WX /nologo /openmp /EHsc") 97 | set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS} /Zi /EHsc /Od") 98 | endif() 99 | 100 | # Don't skip the full RPATH for the build/install tree 101 | set(CMAKE_SKIP_RPATH FALSE) 102 | set(CMAKE_BUILD_WITH_INSTALL_RPATH FALSE) 103 | 104 | if(APPLE) 105 | message (STATUS "Setting OSX-specific settings...") 106 | set(CMAKE_INSTALL_NAME_DIR "@rpath") 107 | set(CMAKE_INSTALL_RPATH "${MAYA_LIBRARY_DIR};${MAYA_FRAMEWORK_DIR}") 108 | endif(APPLE) 109 | 110 | # Disable RPATH stripping during installation so that the binary will link correctly 111 | # to the Maya libs 112 | set(CMAKE_INSTALL_RPATH_USE_LINK_PATH TRUE) 113 | 114 | # Get the parent installation directory if it exists; this is used to format 115 | # the installation path for the plugins 116 | get_filename_component(PLUGIN_ROOT_DIR ${CMAKE_CURRENT_SOURCE_DIR} DIRECTORY) 117 | if (IS_DIRECTORY ${PLUGIN_ROOT_DIR}/bin) 118 | set(CMAKE_INSTALL_PREFIX ${PLUGIN_ROOT_DIR}/bin) 119 | else() 120 | set(CMAKE_INSTALL_PREFIX ${CMAKE_CURRENT_SOURCE_DIR}/bin) 121 | message(WARNING "Could not find binaries install directory, installing to default one!") 122 | endif() 123 | 124 | # Set sources for the project 125 | set(PLUGIN_SOURCE_FILES "${CMAKE_CURRENT_SOURCE_DIR}/src/plugin_main.cpp") 126 | 127 | # Add targets to build 128 | add_library(${PROJECT_NAME} SHARED ${PLUGIN_SOURCE_FILES}) 129 | # TODO: (sonictk) make tests 130 | # add_executable(${TEST_EXECUTABLE_NAME} ${TEST_SOURCE_FILES} ${PLUGIN_SOURCE_FILES}) 131 | 132 | # Link targets to libraries 133 | message(STATUS "Linking to Maya libraries at: ${MAYA_LIBRARY_DIR}") 134 | target_link_libraries(${PROJECT_NAME} ${MAYA_LIBRARIES}) 135 | # target_link_libraries(${TEST_EXECUTABLE_NAME} ${MAYA_LIBRARIES}) 136 | 137 | # Set preprocessor definitions 138 | MAYA_PLUGIN(${PROJECT_NAME}) 139 | # set_target_properties(${TEST_EXECUTABLE_NAME} PROPERTIES 140 | # COMPILE_DEFINITIONS "${MAYA_COMPILE_DEFINITIONS}") 141 | 142 | install(TARGETS ${PROJECT_NAME} ${MAYA_TARGET_TYPE} DESTINATION ${CMAKE_INSTALL_PREFIX}) 143 | # set(TEST_INSTALL_DIR ${CMAKE_INSTALL_PREFIX}/tests) 144 | 145 | # # Create the directory if it does not already exist because Windows doesn't recognize the 146 | # # install names properly otherwise when copying the DLLs over 147 | # if(WIN32) 148 | # file(MAKE_DIRECTORY ${TEST_INSTALL_DIR}) 149 | # endif(WIN32) 150 | 151 | # install(TARGETS ${TEST_EXECUTABLE_NAME} RUNTIME DESTINATION ${TEST_INSTALL_DIR}) 152 | 153 | # # For standalone linking, run post-build commands to copy necessary dylibs/OSX frameworks 154 | # # to the executable folder 155 | # # If on Windows, because there is extra stuff in Python that relies on the Maya libs directory specifically, 156 | # # create the .bat file for setting the environment for end-users to run the tests with 157 | # if(WIN32) 158 | # file(TO_NATIVE_PATH ${MAYA_LOCATION} MAYA_LOCATION_WIN) 159 | # configure_file("${PROJECT_SOURCE_DIR}/scripts/test_tensionDeformer.bat.in" 160 | # "${TEST_INSTALL_DIR}/test_tensionDeformer.bat" NEWLINE_STYLE CRLF) 161 | 162 | # # If on OSX, since @rpath linking/framework linking is horrendously overcomplicated, copy over the .dylibs 163 | # # and framework files to the application directory as well 164 | # elseif(APPLE) 165 | # file(GLOB MAYA_DYLIBS 166 | # "${MAYA_LIBRARY_DIR}/*.dylib" 167 | # "${MAYA_LIBRARY_DIR}/QtCore" 168 | # "${MAYA_LIBRARY_DIR}/QtDeclarative" 169 | # "${MAYA_LIBRARY_DIR}/QtCore" 170 | # "${MAYA_LIBRARY_DIR}/QtMultimedia" 171 | # "${MAYA_LIBRARY_DIR}/QtHelp" 172 | # "${MAYA_LIBRARY_DIR}/QtGui" 173 | # "${MAYA_LIBRARY_DIR}/QtDesignerComponents" 174 | # "${MAYA_LIBRARY_DIR}/QtDesigner" 175 | # "${MAYA_LIBRARY_DIR}/QtSvg" 176 | # "${MAYA_LIBRARY_DIR}/QtSql" 177 | # "${MAYA_LIBRARY_DIR}/QtScriptTools" 178 | # "${MAYA_LIBRARY_DIR}/QtScript" 179 | # "${MAYA_LIBRARY_DIR}/QtOpenGL" 180 | # "${MAYA_LIBRARY_DIR}/QtNetwork" 181 | # "${MAYA_LIBRARY_DIR}/shiboken" 182 | # "${MAYA_LIBRARY_DIR}/Render" 183 | # "${MAYA_LIBRARY_DIR}/QtXmlPatterns" 184 | # "${MAYA_LIBRARY_DIR}/QtXml" 185 | # "${MAYA_LIBRARY_DIR}/QtWebKit" 186 | # "${MAYA_LIBRARY_DIR}/phonon") 187 | # foreach(DYLIB ${MAYA_DYLIBS}) 188 | # add_custom_command(TARGET ${TEST_EXECUTABLE_NAME} POST_BUILD 189 | # COMMAND ${CMAKE_COMMAND} -E 190 | # copy_if_different "${DYLIB}" "${TEST_INSTALL_DIR}" 191 | # COMMENT "Copying ${DYLIB} to installation directory...") 192 | # endforeach() 193 | 194 | # add_custom_command(TARGET ${TEST_EXECUTABLE_NAME} POST_BUILD 195 | # COMMAND ${CMAKE_COMMAND} -E copy_directory "${MAYA_LIBRARY_DIR}/plug-ins" "${TEST_INSTALL_DIR}/plug-ins" 196 | # COMMENT "Copying Maya plug-ins to installation directory...") 197 | 198 | # add_custom_command(TARGET ${TEST_EXECUTABLE_NAME} POST_BUILD 199 | # COMMAND ${CMAKE_COMMAND} -E copy_directory "${MAYA_LIBRARY_DIR}/rendererDesc" "${TEST_INSTALL_DIR}/rendererDesc" 200 | # COMMENT "Copying Maya renderer XML configuration files to installation directory...") 201 | 202 | # set(FRAMEWORKS_INSTALL_DIR "${CMAKE_INSTALL_PREFIX}/Frameworks") 203 | # add_custom_command(TARGET ${TEST_EXECUTABLE_NAME} POST_BUILD 204 | # COMMAND ${CMAKE_COMMAND} -E copy_directory "${MAYA_FRAMEWORK_DIR}" "${FRAMEWORKS_INSTALL_DIR}" 205 | # COMMENT "Copying ${MAYA_FRAMEWORK_DIR} to ${FRAMEWORKS_INSTALL_DIR}...") 206 | # endif() 207 | -------------------------------------------------------------------------------- /COPYING: -------------------------------------------------------------------------------- 1 | GNU GENERAL PUBLIC LICENSE 2 | Version 3, 29 June 2007 3 | 4 | Copyright (C) 2007 Free Software Foundation, Inc. 5 | Everyone is permitted to copy and distribute verbatim copies 6 | of this license document, but changing it is not allowed. 7 | 8 | Preamble 9 | 10 | The GNU General Public License is a free, copyleft license for 11 | software and other kinds of works. 12 | 13 | The licenses for most software and other practical works are designed 14 | to take away your freedom to share and change the works. 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Revised Versions of the GNU Lesser General Public License. 145 | 146 | The Free Software Foundation may publish revised and/or new versions 147 | of the GNU Lesser General Public License from time to time. Such new 148 | versions will be similar in spirit to the present version, but may 149 | differ in detail to address new problems or concerns. 150 | 151 | Each version is given a distinguishing version number. If the 152 | Library as you received it specifies that a certain numbered version 153 | of the GNU Lesser General Public License "or any later version" 154 | applies to it, you have the option of following the terms and 155 | conditions either of that published version or of any later version 156 | published by the Free Software Foundation. If the Library as you 157 | received it does not specify a version number of the GNU Lesser 158 | General Public License, you may choose any version of the GNU Lesser 159 | General Public License ever published by the Free Software Foundation. 160 | 161 | If the Library as you received it specifies that a proxy can decide 162 | whether future versions of the GNU Lesser General Public License shall 163 | apply, that proxy's public statement of acceptance of any version is 164 | permanent authorization for you to choose that version for the 165 | Library. 166 | -------------------------------------------------------------------------------- /docs/index.md: -------------------------------------------------------------------------------- 1 | # Tutorial on how to write a install-able Maya node # 2 | 3 | ## About ## 4 | 5 | This is a tutorial on how to write a node that sets up features in your Maya 6 | scene without having explicit dirty propagation relationships in the dependency graph. 7 | 8 | For this node, we're going to focus mostly on the *how* of writing the node 9 | itself, and thus the actual functionality will be restricted to something very 10 | basic; in this case, creating a spiral motion when a user moves the transform 11 | node in the scene that we set up the feature for. 12 | 13 | All the source code for this example node is available [here](https://github.com/sonictk/maya_node_callback_example). 14 | 15 | ### What exactly is this approach? 16 | 17 | You know how you "normally" do an IK/FK switch in a rig by having 2 joint chains, 18 | constrain them both to a 3rd joint chain, and then have a bunch of connections in 19 | the Node Editor tied to some custom attribute on some transform node to blend the 20 | constraints? 21 | 22 | Think about it for a second: rather than having this "feature" be built into the 23 | dependency graph of the rig itself, why not have it be able to be set up 24 | *on-demand*? There is no *reason* that this feature needs to stay in the rig, 25 | which creates all sorts of complications when you switch between the IK/FK 26 | chains and affect the dependency graph unnecessarily. In short, **there's no 27 | need to store this feature as a fixed state in the dependency graph.** 28 | 29 | By utilizing the callback mechanism of Maya, we can avoid having to "bake" this 30 | features/state into the rig, and setup our desired rig behaviours completely 31 | independently of what the rig's graph might actually have, at runtime. We can 32 | also un-install this feature as well, *all without affecting the original 33 | graph*. This philosophy makes it tremendously easy to reason about components of 34 | the rig independently. (Very much like traditional software development!) 35 | 36 | Now, it's important to note that not all problems lend themselves well to this 37 | approach; particularly, problems that are *stateful* (i.e. are tied to time, 38 | velocity, etc.). Those problems tend to require a little more careful thought in 39 | order to determine their suitability towards such an approach. 40 | 41 | For more information on this approach to installing scene features on-demand, 42 | please refer to *Raffaele Fragapane's* [Cult Of Rig](http://www.cultofrig.com/2017/07/22/ 43 | pilot-season-day-16-automatically-loading-callbacks-scene-load/) 44 | series on the thought process behind this approach. He goes over it in a lot 45 | more detail. 46 | 47 | ### Why not just do what Raffaele does and use a ``scriptNode``? 48 | 49 | The reason we're using a compiled node here instead of a ``scriptNode`` as he 50 | details in the original approach is due to the fact that the script executed 51 | from a script node in Maya has no concept of which node executed it, and thus 52 | makes it very difficult to implement in production when you reference this 53 | script node in a separate namespace without implementing a callback manager of 54 | some sort to manage the callbacks you are installing into the scene, along with 55 | managing the associated namespaces/nodes for each of those callbacks registered 56 | by the script node. 57 | 58 | By using a compiled node instead, we can manage all of that registration/ 59 | un-registration mess within the node itself much more cleanly and reason about 60 | the state of our Maya scene a lot more easily than a script node would otherwise 61 | have allowed for. 62 | 63 | ## Requirements ## 64 | 65 | ### What you should know ### 66 | 67 | - **Basic knowledge of C/C++**. I will focus on including only the code that is 68 | important; I expect you to be able to understand how to fill in the rest as needed. 69 | - Knowledge of how the dependency graph works in Maya and how dirty propagation works. 70 | - **Basic knowledge of how Maya plugins work and how to write/build them**. There is 71 | a sample ``CMakeLists.txt`` build script provided for reference if you need a 72 | refresher on that. 73 | - If you're unfamilar with Maya's callback mechanisms, to **watch the stream** 74 | listed above to get an idea of what's going on and how they tie to dirty 75 | propagation in the dependency graph. 76 | - Most importantly: **How to convert between tabs/spaces.** (Of course, you 77 | should also prefer tabs, but this is a well-understood *fact*, and so I don't 78 | think further discussion is required on the topic.) 79 | 80 | ## Getting started ## 81 | 82 | Firstly, we'll just get a basic skeleton setup of the plugin going. As a refresher, 83 | this just means that you need to create a defintion of a ``MPxNode`` 84 | that implements a creator function and an initializer function, which 85 | we will call ``creator()`` and ``initialize()`` respectively. 86 | 87 | Thus, in ``callback_node.h``: 88 | 89 | ```c++ 90 | /// This is a dependency node that will install a callback during its lifetime. 91 | class CallbackNode : MPxNode 92 | { 93 | public: 94 | static void *creator(); 95 | 96 | static MStatus initialize(); 97 | 98 | static const MTypeId kNODE_ID; /// The unique ID that identifies this node. 99 | static const MString kNODE_NAME; /// The name of the DG node. 100 | ``` 101 | 102 | And ``callback_node.cpp``, which, for now, looks pretty sparse: 103 | 104 | ```c++ 105 | #include "callback_node.h" 106 | 107 | const MTypeId CallbackNode::kNODE_ID(0x0007ffff); 108 | const MString CallbackNode::kNODE_NAME = "callbackNodeExample"; 109 | 110 | 111 | void *CallbackNode::creator() 112 | { 113 | return new CallbackNode(); 114 | } 115 | 116 | 117 | MStatus CallbackNode::initialize() 118 | { 119 | MStatus result; 120 | return result; 121 | } 122 | ``` 123 | 124 | We also add two extra attributes called ``kNODE_ID`` and ``kNODE_NAME`` to help 125 | us identify the dependency node later on. 126 | 127 | Great! We've got our node now, let's write the basic plugin structure to 128 | register it. In case you needed a refresher: 129 | 130 | In ``plugin_main.cpp``: 131 | 132 | ```c++ 133 | #include "plugin_main.h" 134 | #include 135 | 136 | const char *kAUTHOR = "Me, the author"; 137 | const char *kVERSION = "1.0.0"; 138 | const char *kREQUIRED_API_VERSION = "Any"; 139 | 140 | 141 | MStatus initializePlugin(MObject obj) 142 | { 143 | MStatus status; 144 | MFnPlugin plugin(obj, kAUTHOR, kVERSION, kREQUIRED_API_VERSION); 145 | 146 | status = plugin.registerNode(CallbackNode::kNODE_NAME, 147 | CallbackNode::kNODE_ID, 148 | &CallbackNode::creator, 149 | &CallbackNode::initialize, 150 | MPxNode::kDependNode); 151 | CHECK_MSTATUS_AND_RETURN_IT(status); 152 | 153 | return status; 154 | } 155 | 156 | 157 | MStatus uninitializePlugin(MObject obj) 158 | { 159 | MFnPlugin plugin(obj); 160 | 161 | MStatus status; 162 | status = plugin.deregisterNode(CallbackNode::kNODE_ID); 163 | CHECK_MSTATUS_AND_RETURN_IT(status); 164 | 165 | return status; 166 | } 167 | ``` 168 | 169 | In ``plugin_main.h``, I go ahead and setup a [Single Translation Unit (STU) 170 | Build/Unity build](https://stackoverflow.com/questions/543697/include-all-cpp- 171 | files-into-a-single-compilation-unit) (which is easy, since there's only one 172 | source file right now): 173 | 174 | ```c++ 175 | #include "callback_node.cpp" 176 | 177 | MStatus initializePlugin(MObject obj); 178 | 179 | MStatus uninitializePlugin(MObject obj); 180 | ``` 181 | 182 | You should be able to call the compiler command on your corresponding platform 183 | on just ``plugin_main.cpp`` and have the plugin compile correctly. 184 | 185 | *I will not go into the details regarding a STU build here, but suffice to say 186 | that I have found them much more beneficial to build times than any other 187 | compiler feature (LTO, IncrediBuild, splitting the code out into pre-compiled 188 | libs, whatever). For such a small project, it doesn't matter; you can switch back 189 | to a more traditional build setup if you prefer.* 190 | 191 | *If you have issues building the plugin on your own, please refer to the 192 | included ``CMakeLists.txt`` to see how I manage my own builds. You are not 193 | required to use CMake; it is just my own preference.* 194 | 195 | If you got past all that and got a plugin building, great! We have a node that 196 | does...well, *nothing*. 197 | 198 | Now we just need to make it work. 199 | 200 | 201 | ### What are we even doing? ### 202 | 203 | So before we jump into the node's features itself, let's take a step back and 204 | think about what we want this node to do at a high-level: 205 | 206 | {% dot high_level_overview.svg 207 | 208 | digraph callbackNodeExample { 209 | graph[fontname="Arial", fontsize=14, nodesep=1]; 210 | node[fontname="Arial", fontsize=14, shape=box]; 211 | edge[fontname="Arial", fontsize=10]; 212 | transform[label="Transform node", shape=oval]; 213 | callback[label="Callback node"]; 214 | transform -> callback[label=" 1. Read translateX"]; 215 | callback -> transform[label=" 2. Set new translate Y/Z in a spiral-ly fashion", color=red, style=dashed]; 216 | } 217 | 218 | %} 219 | 220 | Ok. So we know that we want our node to read the translate information from the 221 | transform node. However, I just promised that we wouldn't have explicit 222 | connections between our nodes in the DG. So what we'll do instead is use 223 | *message attributes* to do the job of making sure our nodes know about each 224 | other. Kind of like Tinder, but just for DG nodes. 225 | 226 | ### Creating the message attribute ### 227 | 228 | If you need a refresher on what a message attribute is: 229 | 230 | > **A message attribute is a dependency node attribute that does not transmit 231 | > data**. *Message attributes only exist to formally declare relationships between 232 | > nodes. By connecting two nodes via message attributes, a relationship between 233 | > those nodes is expressed.* 234 | > 235 | > *The Maya Documentation for ``MFnMessageAttribute``, verse 2:0* 236 | 237 | Basically, by utilizing this Maya feature, we'll be able to avoid having any data 238 | transmitted explicitly in the graph; we'll be reading it directly from the 239 | transform node itself. 240 | 241 | Let's add this message attribute to our custom node definition: 242 | 243 | ```c++ 244 | const char *CallbackNode::kIN_TRANSFORM_ATTR_NAME = "transform"; 245 | MObject CallbackNode::inTransformAttr; 246 | 247 | 248 | MStatus CallbackNode::initialize() 249 | { 250 | MStatus result; 251 | 252 | MFnMessageAttribute fnMsgAttr; 253 | inTransformAttr = fnMsgAttr.create(CallbackNode::kIN_TRANSFORM_ATTR_NAME, 254 | CallbackNode::kIN_TRANSFORM_ATTR_NAME, 255 | &result); 256 | CHECK_MSTATUS_AND_RETURN_IT(result); 257 | 258 | addAttribute(inTransformAttr); 259 | return result; 260 | } 261 | ``` 262 | However, let's not forget that this attribute needs to be connected to 263 | something. In this case, that something is the transform node that we're going 264 | to be moving around. 265 | 266 | ### Writing the ``MPxCommand`` to setup everything ### 267 | 268 | To make things easier for our end-users, let's make a ``MPxCommand`` that they 269 | can run in order to create our node automatically, along with handling the connections 270 | between it and the transform node. If you've never written such a thing before 271 | or need some reference, the command I've written is below: 272 | 273 | ``apply_callback_command.h`` 274 | 275 | ```c++ 276 | class ApplyCallbackCommand : public MPxCommand 277 | { 278 | public: 279 | static void *creator(); 280 | 281 | MStatus doIt(const MArgList &args); 282 | 283 | MStatus redoIt(); 284 | 285 | MStatus undoIt(); 286 | 287 | bool isUndoable() const; 288 | 289 | static MSyntax newSyntax(); 290 | 291 | /// The name of the command that is meant to be run. 292 | static const MString kCOMMAND_NAME; 293 | 294 | MStatus parseArgs(const MArgList &args); 295 | 296 | /// Storage for the flag arguments that will be passed into the command. 297 | bool flagHelpSpecified = false; 298 | MSelectionList flagSelList; 299 | 300 | /// Storage for the operations that this command performs on the DG so that we 301 | /// can undo them if necessary. 302 | MDGModifier dgMod; 303 | }; 304 | ``` 305 | 306 | Let's go over method-by-method of how to implement each of these in 307 | ``apply_callback_command.cpp``: 308 | 309 | First, let's define some of the constants we'll be using: 310 | 311 | ```c++ 312 | 313 | const char *flagSelListLongName = "-node"; 314 | const char *flagSelListShortName = "-n"; 315 | 316 | const char *flagHelpLongName = "-help"; 317 | const char *flagHelpShortName = "-h"; 318 | 319 | const char *helpText = "This command will setup a callback on a given node.\n" 320 | "Usage:\n applyCallback [options]\n" 321 | "Options:\n" 322 | "-h / -help Prints this message.\n\n" 323 | "-n / -node The name of the node to setup the callback example for.\n\n"; 324 | 325 | const MString ApplyCallbackCommand::kCOMMAND_NAME = "applyCallback"; 326 | 327 | ``` 328 | 329 | The creator function will basically return a new instance of the command. 330 | 331 | ```c++ 332 | 333 | void *ApplyCallbackCommand::creator() 334 | { 335 | return new ApplyCallbackCommand(); 336 | } 337 | 338 | ``` 339 | 340 | The ``newSyntax()`` function is one we define ourselves, and it's what sets up the 341 | actual parameters that the command will accept in Maya. We'll also implement ``parseArgs()`` 342 | to actually take the arguments we give to the command and figure out if we're 343 | just calling it with a help flag, or if we're actually passing an object in. 344 | 345 | ```c++ 346 | MSyntax ApplyCallbackCommand::newSyntax() 347 | { 348 | MSyntax syntax; 349 | syntax.addFlag(flagHelpShortName, flagHelpLongName); 350 | syntax.addFlag(flagSelListShortName, flagSelListLongName, MSyntax::kSelectionItem); 351 | syntax.enableQuery(false); 352 | syntax.enableEdit(false); 353 | syntax.useSelectionAsDefault(true); 354 | 355 | return syntax; 356 | } 357 | 358 | 359 | MStatus ApplyCallbackCommand::parseArgs(const MArgList &args) 360 | { 361 | MStatus result; 362 | MArgDatabase argDb(syntax(), args, &result); 363 | CHECK_MSTATUS_AND_RETURN_IT(result); 364 | 365 | if (argDb.isFlagSet(flagHelpShortName)) { 366 | displayInfo(helpText); 367 | flagHelpSpecified = true; 368 | return MStatus::kSuccess; 369 | } else { 370 | flagHelpSpecified = false; 371 | } 372 | 373 | if (argDb.isFlagSet(flagSelListShortName)) { 374 | argDb.getFlagArgument(flagSelListShortName, 0, flagSelList); 375 | } 376 | 377 | return result; 378 | } 379 | 380 | ``` 381 | 382 | The ``doIt`` and ``redoIt`` functions are where the meat of the command happens; 383 | ``doIt`` basically calls ``redoIt`` (so that redos actually work correctly!). We 384 | create a new callback node, along with checking if the transform node passed into 385 | the command is valid. 386 | 387 | ```c++ 388 | 389 | MStatus ApplyCallbackCommand::doIt(const MArgList &args) 390 | { 391 | setCommandString(ApplyCallbackCommand::kCOMMAND_NAME); 392 | clearResult(); 393 | 394 | MStatus result = parseArgs(args); 395 | CHECK_MSTATUS_AND_RETURN_IT(result); 396 | 397 | if (this->flagHelpSpecified == true) { 398 | return MStatus::kSuccess; 399 | } 400 | 401 | return redoIt(); 402 | } 403 | 404 | 405 | MStatus ApplyCallbackCommand::redoIt() 406 | { 407 | MStatus result; 408 | if (flagSelList.length() != 1) { 409 | MGlobal::displayError("You need to select a single node to apply the callback to!"); 410 | return MStatus::kInvalidParameter; 411 | } 412 | 413 | if (doesCallbackNodeAlreadyExist() == true) { 414 | MGlobal::displayError("The feature already exists!"); 415 | return MStatus::kFailure; 416 | } 417 | 418 | MObject callbackNode = dgMod.createNode(CallbackNode::kNODE_ID, &result); 419 | CHECK_MSTATUS_AND_RETURN_IT(result); 420 | result = dgMod.doIt(); 421 | CHECK_MSTATUS_AND_RETURN_IT(result); 422 | 423 | MFnDependencyNode fnNode(callbackNode); 424 | MPlug callbackNodeMsgPlug = fnNode.findPlug(CallbackNode::kIN_TRANSFORM_ATTR_NAME, 425 | false, 426 | &result); 427 | CHECK_MSTATUS_AND_RETURN_IT(result); 428 | 429 | MObject transform; 430 | result = flagSelList.getDependNode(0, transform); 431 | CHECK_MSTATUS_AND_RETURN_IT(result); 432 | if (!transform.hasFn(MFn::kDependencyNode)) { 433 | MGlobal::displayError("The object specified is not a valid DG node!"); 434 | return MStatus::kInvalidParameter; 435 | } 436 | 437 | return result; 438 | } 439 | 440 | ``` 441 | 442 | As for ``isUndoable()``, we just basically tell Maya that this command is undo-able, 443 | and implement the functionality in ``undoIt()`` by deleting the node. 444 | 445 | ```c++ 446 | 447 | MStatus ApplyCallbackCommand::undoIt() 448 | { 449 | dgMod.undoIt(); 450 | return MStatus::kSuccess; 451 | } 452 | 453 | 454 | bool ApplyCallbackCommand::isUndoable() const 455 | { 456 | if (flagHelpSpecified == true) { 457 | return false; 458 | } else { 459 | return true; 460 | } 461 | } 462 | ``` 463 | 464 | It's a bit of boilerplate code to write, but it's not that complicated when you 465 | see what it's actually doing. We basically create a new ``CallbackNode``, 466 | accept a single transform as a command argument, and do some basic sanity 467 | checking of the inputs to make sure everything's good. Nothing special, really. 468 | 469 | *(Again, if something here doesn't make sense to you, please look through some of 470 | the examples of how to write command plugins in the Maya documentation.)* 471 | 472 | There's one thing we need to do before we call this command good, though; we 473 | need to actually make the connection between the callback node and the transform 474 | node that we pass to the command: 475 | 476 | ```c++ 477 | //... the earlier part of redoIt() 478 | MObject transform; 479 | result = flagSelList.getDependNode(0, transform); 480 | CHECK_MSTATUS_AND_RETURN_IT(result); 481 | if (!transform.hasFn(MFn::kDependencyNode)) { 482 | MGlobal::displayError("The object specified is not a valid DG node!"); 483 | return MStatus::kInvalidParameter; 484 | } 485 | result = fnNode.setObject(transform); 486 | CHECK_MSTATUS_AND_RETURN_IT(result); 487 | if (!fnNode.hasAttribute(CallbackNode::kMSG_CXN_ATTR_NAME)) { 488 | MFnMessageAttribute fnMsgAttr; 489 | MObject msgAttr = fnMsgAttr.create(CallbackNode::kMSG_CXN_ATTR_NAME, 490 | CallbackNode::kMSG_CXN_ATTR_NAME, 491 | &result); 492 | CHECK_MSTATUS_AND_RETURN_IT(result); 493 | fnNode.addAttribute(msgAttr); 494 | } 495 | MDGModifier dgModCxn; 496 | MPlug msgPlug = fnNode.findPlug(CallbackNode::kMSG_CXN_ATTR_NAME, false, &result); 497 | CHECK_MSTATUS_AND_RETURN_IT(result); 498 | result = dgModCxn.connect(msgPlug, callbackNodeMsgPlug); 499 | CHECK_MSTATUS_AND_RETURN_IT(result); 500 | dgModCxn.doIt(); 501 | ``` 502 | 503 | We basically create a new message attribute on the transform node and connect it 504 | up (using a different ``MDGModifier``, since our internal one is going to be 505 | reserved for deleting the callback node we created if the user chooses to undo, 506 | and deleting the node will automatically break the connections anyway) 507 | 508 | We also need to define ``CallbackNode::kMSG_CXN_ATTR_NAME`` and 509 | ``CallbackNode::kIN_TRANSFORM_ATTR_NAME``, which will be the names of the 510 | message attributes on the callback and transform nodes respectively. You can do 511 | that in the respective source files however you like. 512 | 513 | Finally, we should also probably register/de-register this command so that we can 514 | actually use it proper: 515 | 516 | ```c++ 517 | 518 | MStatus initializePlugin(MObject obj) 519 | { 520 | // ...previous stuff 521 | 522 | status = plugin.registerCommand(ApplyCallbackCommand::kCOMMAND_NAME, 523 | ApplyCallbackCommand::creator, 524 | ApplyCallbackCommand::newSyntax); 525 | CHECK_MSTATUS_AND_RETURN_IT(status); 526 | 527 | return status; 528 | } 529 | 530 | 531 | MStatus uninitializePlugin(MObject obj) 532 | { 533 | // ...again, more previous stuff 534 | 535 | status = plugin.deregisterCommand(ApplyCallbackCommand::kCOMMAND_NAME); 536 | CHECK_MSTATUS_AND_RETURN_IT(status); 537 | 538 | return status; 539 | } 540 | 541 | ``` 542 | 543 | ## Getting somewhere ## 544 | 545 | Once all of that is done and your plugin is built, you should be able to run the 546 | following MEL script (or similar): 547 | 548 | ``` 549 | file -f -newFile; 550 | unloadPlugin "callbackNodeExample"; 551 | loadPlugin "c:/Users/sonictk/Git/experiments/maya_node_callback_example/build/Debug/callbackNodeExample.mll"; 552 | 553 | createNode "transform"; 554 | applyCallback -n "transform1"; 555 | ``` 556 | 557 | Which should give you something similar to the following: 558 | 559 | {% dot msg_cxn_setup.svg 560 | 561 | digraph callbackNodeExample { 562 | graph[fontname="Arial", fontsize=12, nodesep=1, rankdir=LR]; 563 | node[fontname="Arial", fontsize=12, shape=Mrecord]; 564 | edge[fontname="Arial", fontsize=10]; 565 | transform[label="Transform node|callback node msg. attr."]; 566 | callback[label="Callback node|transform node msg. attr."]; 567 | transform:f1 -> callback:f1[label="message conn.", color=blue]; 568 | } 569 | 570 | %} 571 | 572 | If you're still following along; great! Let's now focus on actually *doing* 573 | something useful with the nodes we've made. 574 | 575 | ### A more detailed overview of the entire setup ### 576 | 577 | Now that we've established the relationship between the nodes, let's think about 578 | what we need to do next. We know that we want to get the ``translateX`` value 579 | from the transform node whenever a user changes it interactively. We also know 580 | that we don't want this behaviour to be dirty propagation-based (i.e. no 581 | explicit connection in the graph). 582 | 583 | If you paid attention at all during the stream, you'll know what the answer is: 584 | it's in the form of Maya's various callback mechanisms. However, before we jump 585 | right into writing it up, let's think a little again over what we need to do in 586 | greater detail this time: 587 | 588 | {% dot cb_setup.svg 589 | 590 | digraph callbackNodeExample { 591 | graph[fontname="Arial", fontsize=10, nodesep=1, rankdir=LR]; 592 | node[fontname="Arial", fontsize=10, shape=Mrecord]; 593 | edge[fontname="Arial", fontsize=8]; 594 | transform[label="Transform node|callback node msg. attr.|translateX|attr. changed callback|translateY/Z"]; 595 | callback[label="Callback node|transform node msg. attr.|installation callback|callback registry"]; 596 | readTranslateXCB[label="Callback function", shape=oval, style=dashed]; 597 | transform:f1 -> callback:f1[label="message conn.", color=blue, fontcolor=blue]; 598 | callback:f2 -> transform:f3[label="1. Registers this callback when \nnode is created/connected", color=red, fontcolor=red, style=dashed]; 599 | transform:f3 -> readTranslateXCB[label="2. Calls function when translateX. \nchanges interactively on transform node", color=green, fontcolor=green]; 600 | transform:f2 -> transform:f3[color=green, style=dotted]; 601 | readTranslateXCB -> transform:f4:s[label="3. Sets final ty/tz values \non the transform node", color=brown, fontcolor=brown, style=dashed]; 602 | transform:f3 -> callback:f3[label="callback ID is stored so that \nit can be un-registered on node \ndeletion/disconnection", style=dashed, color=grey, fontcolor=grey]; 603 | } 604 | 605 | %} 606 | 607 | Ok, that's a little confusing. As 608 | a [great man](https://en.wikipedia.org/wiki/Logic_(musician)) 609 | once said, let's [break it down](https://www.youtube.com/watch?v=UhAml-4uDco). 610 | 611 | ### Registering the callback onto the transform node ### 612 | 613 | {% dot cb_setup_p1.svg 614 | 615 | digraph callbackNodeExample { 616 | graph[fontname="Arial", fontsize=10, nodesep=1, rankdir=LR]; 617 | node[fontname="Arial", fontsize=10, shape=Mrecord]; 618 | edge[fontname="Arial", fontsize=8]; 619 | transform[label="Transform node|callback node msg. attr.|translateX|attr. changed callback|translateY/Z"]; 620 | callback[label="Callback node|transform node msg. attr.|installation callback|callback registry"]; 621 | readTranslateXCB[label="Callback function", shape=oval, style=dashed]; 622 | transform:f1 -> callback:f1[label="message conn.", color=blue, fontcolor=blue]; 623 | callback:f2 -> transform:f3[label="1. Registers this callback when \nnode is created/connected", color=grey, fontcolor=grey, style=dotted]; 624 | transform:f3 -> readTranslateXCB[label="2. Calls function when 625 | translateX. \nchanges interactively on transform node", color=grey, fontcolor=grey, style=dotted]; 626 | transform:f2 -> transform:f3[color=grey, style=dotted]; 627 | readTranslateXCB -> transform:f4:s[label="3. Sets final ty/tz values \non the transform node", color=grey, fontcolor=grey, style=dotted]; 628 | transform:f3 -> callback:f3[label="callback ID is stored so that \nit can be un-registered on node \ndeletion/disconnection", style=dotted, color=grey, fontcolor=grey]; 629 | } 630 | 631 | %} 632 | 633 | We already did the message connection earlier, so we can move on. 634 | 635 | {% dot cb_setup_p1.svg 636 | 637 | digraph callbackNodeExample { 638 | graph[fontname="Arial", fontsize=10, nodesep=1, rankdir=LR]; 639 | node[fontname="Arial", fontsize=10, shape=Mrecord]; 640 | edge[fontname="Arial", fontsize=8]; 641 | transform[label="Transform node|callback node msg. attr.|translateX|attr. changed callback|translateY/Z"]; 642 | callback[label="Callback node|transform node msg. attr.|installation callback|callback registry"]; 643 | readTranslateXCB[label="Callback function", shape=oval, style=dashed]; 644 | transform:f1 -> callback:f1[label="message conn.", color=grey, fontcolor=grey, style=dotted]; 645 | callback:f2 -> transform:f3[label="1. Registers this callback when \nnode is created/connected", color=red, fontcolor=red]; 646 | transform:f3 -> readTranslateXCB[label="2. Calls function when 647 | translateX. \nchanges interactively on transform node", color=grey, fontcolor=grey, style=dotted]; 648 | transform:f2 -> transform:f3[color=grey, style=dotted]; 649 | readTranslateXCB -> transform:f4:s[label="3. Sets final ty/tz values \non the transform node", color=grey, fontcolor=grey, style=dotted]; 650 | transform:f3 -> callback:f3[label="callback ID is stored so that \nit can be un-registered on node \ndeletion/disconnection", style=dotted, color=grey, fontcolor=grey]; 651 | } 652 | 653 | %} 654 | 655 | Let's start here instead. We need to set-up a callback on the callback node when 656 | it is created that is responsible for *setting up another callback on the 657 | transform node* in order to watch for any attribute changes on it. We can do 658 | this by making use of the ``MPxNode::postConstructor`` virtual method, like so: 659 | 660 | ```c++ 661 | 662 | void CallbackNode::postConstructor() 663 | { 664 | MStatus status; 665 | MObject thisNode = thisMObject(); 666 | 667 | MCallbackId installId = MNodeMessage::addAttributeChangedCallback(thisNode, 668 | installCallback, 669 | NULL, 670 | &status); 671 | if (status != MStatus::kSuccess) { 672 | MGlobal::displayError("Unable to install example feature!"); 673 | uninstallCallback(); 674 | return; 675 | } 676 | callbacks.append(installId); 677 | MNodeMessage::addNodePreRemovalCallback(thisNode, 678 | uninstallCallback, 679 | NULL, 680 | &status); 681 | if (status != MStatus::kSuccess) { 682 | MGlobal::displayError("Unable to install example feature!"); 683 | uninstallCallback(); 684 | return; 685 | } 686 | } 687 | 688 | ``` 689 | 690 | What are ``installCallback`` and ``uninstallCallback``, you ask? Let's take a 691 | look at the documentation for both ``MNodeMessage::addAttributeChangedCallback`` 692 | and ``MNodeMessage::addNodePreRemovalCallback`` to get some hints: 693 | 694 | ```c++ 695 | MCallbackId addAttributeChangedCallback(MObject &node, 696 | MNodeMessage::MAttr2PlugFunction func, 697 | void *clientData = NULL, 698 | MStatus *ReturnStatus = NULL) 699 | 700 | MCallbackId addNodePreRemovalCallback(MObject &node, 701 | MMessage::MNodeFunction func, 702 | void *clientData = NULL, 703 | MStatus *ReturnStatus = NULL) 704 | ``` 705 | 706 | So basically our ``installCallback`` and ``uninstallCallback`` functions need to 707 | match the signatures of a ``MAttr2PlugFunction`` and a ``MNodeFunction``, 708 | whatever those might be. Looking at an ``MAttr2PlugFunction`` signature gives 709 | the following: 710 | 711 | ```c++ 712 | 713 | typedef void(* MAttr2PlugFunction) (MNodeMessage::AttributeMessage msg, 714 | MPlug &plug, 715 | MPlug &otherPlug, 716 | void *clientData) 717 | 718 | ``` 719 | 720 | Basically a function pointer that takes two ``MPlugs``. And a ``MNodeFunction``? 721 | 722 | ```c++ 723 | 724 | typedef void(* MNodeFunction) (MObject &node, void *clientData) 725 | 726 | ``` 727 | 728 | Yep, a function pointer that takes a ``MObject`` node. Not terribly complicated, 729 | which is always good. 730 | 731 | Knowing this, we can go ahead and starting writing our callback functions. The 732 | first will be ``uninstallCallback``, which basically just un-registers all the 733 | callbacks that currently exist in the *callback registry* (We'll worry about 734 | this in a bit). We have an overloaded version that returns nothing, and takes an 735 | ``MObject&`` along with some arbitrary data in order to match the function 736 | pointer signature detailed above. 737 | 738 | ```c++ 739 | 740 | MStatus uninstallCallback() 741 | { 742 | MStatus status = MMessage::removeCallbacks(CallbackNode::callbacks); 743 | MGlobal::displayInfo("Removed feature!"); 744 | return status; 745 | } 746 | 747 | 748 | void uninstallCallback(MObject &node, void *data) 749 | { 750 | uninstallCallback(); 751 | } 752 | 753 | ``` 754 | 755 | With that done, we can then go ahead and implement the callback that handles installation 756 | of the callback onto the transform node itself. 757 | 758 | ```c++ 759 | 760 | void installCallback(MNodeMessage::AttributeMessage msg, 761 | MPlug &plug, 762 | MPlug &otherPlug, 763 | void *data) 764 | { 765 | if (msg == (MNodeMessage::kConnectionBroken| 766 | MNodeMessage::kIncomingDirection| 767 | MNodeMessage::kOtherPlugSet)) { 768 | uninstallCallback(); 769 | } 770 | if (msg != (MNodeMessage::kConnectionMade| 771 | MNodeMessage::kIncomingDirection| 772 | MNodeMessage::kOtherPlugSet)) { 773 | return; 774 | } 775 | // NOTE: (sonictk) We check if the node has its message connection connected 776 | // first to determine if we should install the real callback onto that node 777 | MObject callbackNode = plug.node(); 778 | MFnDependencyNode fnNode(callbackNode); 779 | MPlug cxnPlug = fnNode.findPlug(CallbackNode::kIN_TRANSFORM_ATTR_NAME); 780 | MPlugArray connectedPlugs; 781 | cxnPlug.connectedTo(connectedPlugs, true, false); 782 | if (connectedPlugs.length() != 1) { 783 | return; 784 | } 785 | MObject transformNode = connectedPlugs[0].node(); 786 | if (!transformNode.hasFn(MFn::kTransform)) { 787 | return; 788 | } 789 | // NOTE: (sonictk) Install the callback onto the other node and add it to the 790 | // registry of callbacks to track 791 | MStatus status; 792 | MCallbackId featureCallbackId = MNodeMessage::addAttributeChangedCallback(transformNode, 793 | featureCallback, 794 | NULL, 795 | &status); 796 | if (status != MStatus::kSuccess) { 797 | return; 798 | } 799 | CallbackNode::callbacks.append(featureCallbackId); 800 | MGlobal::displayInfo("Feature installed!"); 801 | 802 | } 803 | 804 | ``` 805 | Basically, we check the message type that Maya passes us to see if we care about 806 | the type of event that just occurred, and either remove the callbacks from a 807 | global registry that the node maintains if we detect a disconnection, or install 808 | a new callback onto the transform node otherwise. Yes, this means we also need 809 | to define what this "global callback registry" is: 810 | 811 | ```c++ 812 | static MCallbackIdArray callbacks; 813 | ``` 814 | 815 | That's it. No need to over-complicate matters. (Remember, in a STU build, any 816 | variable with ``static`` storage duration is effectively global!) 817 | 818 | We'll implement ``featureCallback`` in a little bit. For now, let's look at what 819 | our overview looks like now: 820 | 821 | {% dot cb_setup_p1.svg 822 | 823 | digraph callbackNodeExample { 824 | graph[fontname="Arial", fontsize=10, nodesep=1, rankdir=LR]; 825 | node[fontname="Arial", fontsize=10, shape=Mrecord]; 826 | edge[fontname="Arial", fontsize=8]; 827 | transform[label="Transform node|callback node msg. attr.|translateX|attr. changed callback|translateY/Z"]; 828 | callback[label="Callback node|transform node msg. attr.|installation callback|callback registry"]; 829 | readTranslateXCB[label="Callback function", shape=oval, style=dashed]; 830 | transform:f1 -> callback:f1[label="message conn.", color=grey, fontcolor=grey, style=dotted]; 831 | callback:f2 -> transform:f3[label="1. Done!", color=red, fontcolor=red]; 832 | transform:f3 -> readTranslateXCB[label="2. Calls function when 833 | translateX. \nchanges interactively on transform node", color=grey, fontcolor=grey, style=dotted]; 834 | transform:f2 -> transform:f3[color=grey, style=dotted]; 835 | readTranslateXCB -> transform:f4:s[label="3. Sets final ty/tz values \non the transform node", color=grey, fontcolor=grey, style=dotted]; 836 | transform:f3 -> callback:f3[label="callback ID is stored so that \nit can be un-registered on node \ndeletion/disconnection", color=green, fontcolor=green]; 837 | } 838 | 839 | %} 840 | 841 | Yes, we did skip a little ahead, but it was all for a good cause. Let's go ahead 842 | and implement that ``featureCallback`` now to read the ``translateX`` value off 843 | of the transform node. 844 | 845 | ```c++ 846 | 847 | void featureCallback(MNodeMessage::AttributeMessage msg, 848 | MPlug &plug, 849 | MPlug &otherPlug, 850 | void *data) 851 | { 852 | if (msg != (MNodeMessage::kAttributeSet|MNodeMessage::kIncomingDirection)) { 853 | return; 854 | } 855 | const char *plugName = plug.partialName(0,0,0,0,0,1).asChar(); 856 | if (strstr("translateX", plugName) == NULL) { 857 | return; 858 | } 859 | double xVal = plug.asDouble(); 860 | } 861 | ``` 862 | 863 | As we can see, it's very similar in theory to how we implemented 864 | ``installCallback``; the difference here being that we look for a different type 865 | of event (``kAttributeSet`` instead), and we just get the value of the 866 | translateX plug without doing anything else. 867 | 868 | So just like that, our overview looks like this: 869 | 870 | {% dot cb_setup_p1.svg 871 | 872 | digraph callbackNodeExample { 873 | graph[fontname="Arial", fontsize=10, nodesep=1, rankdir=LR]; 874 | node[fontname="Arial", fontsize=10, shape=Mrecord]; 875 | edge[fontname="Arial", fontsize=8]; 876 | transform[label="Transform node|callback node msg. attr.|translateX|attr. changed callback|translateY/Z"]; 877 | callback[label="Callback node|transform node msg. attr.|installation callback|callback registry"]; 878 | readTranslateXCB[label="Callback function", shape=oval, style=dashed]; 879 | transform:f1 -> callback:f1[label="message conn.", color=blue, fontcolor=blue]; 880 | callback:f2 -> transform:f3[label="1. Done!", color=red, fontcolor=red]; 881 | transform:f3 -> readTranslateXCB[label="2. Calls function when translateX. \nchanges interactively on transform node", color=green, fontcolor=green]; 882 | transform:f2 -> transform:f3[color=green]; 883 | readTranslateXCB -> transform:f4:s[label="3. Sets final ty/tz values \non the transform node", color=grey, fontcolor=grey, style=dotted]; 884 | transform:f3 -> callback:f3[label="done!", color=green, fontcolor=green]; 885 | } 886 | 887 | %} 888 | 889 | Fast, wasn't it? 890 | 891 | Now that we're reading the values, we can focus on step 3: setting new values 892 | back onto the transform node. 893 | 894 | ### Getting our spiral behavior working ### 895 | 896 | If you have any background in high school maths at all, you probably know what 897 | comes next: 898 | 899 | ```c++ 900 | void featureCallback(MNodeMessage::AttributeMessage msg, 901 | MPlug &plug, 902 | MPlug &otherPlug, 903 | void *data) 904 | { 905 | if (msg != (MNodeMessage::kAttributeSet|MNodeMessage::kIncomingDirection)) { 906 | return; 907 | } 908 | const char *plugName = plug.partialName(0,0,0,0,0,1).asChar(); 909 | if (strstr("translateX", plugName) == NULL) { 910 | return; 911 | } 912 | MStatus status; 913 | MPlug transformPlug = plug.parent(&status); 914 | if (status != MStatus::kSuccess) { 915 | return; 916 | } 917 | double xVal = plug.asDouble(); 918 | MPlug transformYPlug = transformPlug.child(1, &status); 919 | if (status != MStatus::kSuccess) { 920 | return; 921 | } 922 | MPlug transformZPlug = transformPlug.child(2, &status); 923 | if (status != MStatus::kSuccess) { 924 | return; 925 | } 926 | double newYVal = sin(xVal); 927 | double newZVal = cos(transformZPlug.asDouble() + xVal); 928 | transformYPlug.setDouble(newYVal); 929 | transformZPlug.setDouble(newZVal); 930 | } 931 | ``` 932 | 933 | That's right, simple trigonometry functions! 934 | 935 | And just like that, we're done! 936 | 937 | ...Kind of. There's just a bit of cleanup to do: in the ``uninitializePlugin`` 938 | function we wrote earlier, we need to make sure that we call 939 | ``uninstallCallback()`` as well to remove all the callbacks from the global 940 | registry (since we don't want those to persist if we remove the callback node 941 | from the scene). 942 | 943 | ```c++ 944 | 945 | MStatus uninitializePlugin(MObject obj) 946 | { 947 | MFnPlugin plugin(obj); 948 | MStatus status; 949 | uninstallCallback(); 950 | status = plugin.deregisterNode(CallbackNode::kNODE_ID); 951 | CHECK_MSTATUS_AND_RETURN_IT(status); 952 | 953 | status = plugin.deregisterCommand(ApplyCallbackCommand::kCOMMAND_NAME); 954 | CHECK_MSTATUS_AND_RETURN_IT(status); 955 | 956 | return status; 957 | } 958 | 959 | ``` 960 | 961 | Ok, *now* we're done. 962 | 963 | ## Conclusion ## 964 | 965 | Is this the right solution for everything? No, absolutely not. This method is 966 | best used for installable features onto a rig where you can control the entire 967 | behaviour of the feature within a single set of depedency nodes that you 968 | control. You also need to take care that you do not trigger unnecessary DG 969 | evaluations within your callback methods that could potentially cause cycles in 970 | the DG (which won't be caught by Maya!) 971 | 972 | However, this method will work far better than using ``scriptNodes``, since they 973 | will work even when referenced, thus making them far better suited to 974 | production. You also are able to reason about the current callbacks that have 975 | been registered far more easily than if you had been using script nodes and 976 | managing which ones were registered to which namespace/object combinations in 977 | the scene. 978 | 979 | Use with a healthy dose of caution and wonder, as always! 980 | 981 | 982 | ## Credits ## 983 | 984 | **[Raffaele Fragapane](http://www.cultofrig.com/)**: For the idea regarding this 985 | in the first place, and for being an awesome smart dude. 986 | 987 | **[Ryan Porter](https://github.com/yantor3d)**: For discussing/confirming with me 988 | the limitations of the Maya ``scriptNode`` and for bugging me to write this up in 989 | the first place. 990 | 991 | **Siew Yi Liang**: Duh, I wrote these words and the example code here. You can find 992 | more of my ramblings [here](http://www.sonictk.com/blog). 993 | -------------------------------------------------------------------------------- /mkdocs.yml: -------------------------------------------------------------------------------- 1 | site_name: Maya Callback Node Example Tutorial 2 | theme: cinder 3 | markdown_extensions: 4 | - inline_graphviz 5 | -------------------------------------------------------------------------------- /modules/FindMaya.cmake: -------------------------------------------------------------------------------- 1 | # Maya finder module for CMake 2 | # Usage: 3 | # cmake -G "Visual Studio 11 Win64" -DMAYA_VERSION=2016 ../ 4 | # cmake --build . --config Release 5 | # 6 | # 7 | # Variables that will be defined: 8 | # MAYA_FOUND Defined if a Maya installation has been detected 9 | # MAYA_EXECUTABLE Path to Maya's executable 10 | # MAYA__FOUND Defined if has been found 11 | # MAYA__LIBRARY Path to library 12 | # MAYA_INCLUDE_DIR Path to the devkit's include directories 13 | # MAYA_LIBRARIES All the Maya libraries 14 | # 15 | 16 | # Set a default Maya version if not specified 17 | if(NOT DEFINED MAYA_VERSION) 18 | set(MAYA_VERSION 2016 CACHE STRING "Maya version") 19 | endif() 20 | 21 | # OS Specific environment setup 22 | set(MAYA_COMPILE_DEFINITIONS "REQUIRE_IOSTREAM;_BOOL") 23 | set(MAYA_INSTALL_BASE_SUFFIX "") 24 | set(MAYA_INC_SUFFIX "include") 25 | set(MAYA_LIB_SUFFIX "lib") 26 | set(MAYA_BIN_SUFFIX "bin") 27 | set(MAYA_TARGET_TYPE LIBRARY) 28 | if(WIN32) 29 | # Windows 30 | set(MAYA_INSTALL_BASE_DEFAULT "C:/Program Files/Autodesk") 31 | set(MAYA_COMPILE_DEFINITIONS "${MAYA_COMPILE_DEFINITIONS};NT_PLUGIN") 32 | set(OPENMAYA OpenMaya.lib) 33 | set(MAYA_PLUGIN_EXTENSION ".mll") 34 | set(MAYA_TARGET_TYPE RUNTIME) 35 | elseif(APPLE) 36 | # Apple 37 | set(MAYA_INSTALL_BASE_DEFAULT /Applications/Autodesk) 38 | set(MAYA_INC_SUFFIX "devkit/include") 39 | set(MAYA_LIB_SUFFIX "Maya.app/Contents/MacOS") 40 | set(MAYA_BIN_SUFFIX "Maya.app/Contents/bin/") 41 | set(MAYA_COMPILE_DEFINITIONS "${MAYA_COMPILE_DEFINITIONS};OSMac_") 42 | set(OPENMAYA libOpenMaya.dylib) 43 | set(MAYA_PLUGIN_EXTENSION ".bundle") 44 | else() 45 | # Linux 46 | set(MAYA_COMPILE_DEFINITIONS "${MAYA_COMPILE_DEFINITIONS};LINUX") 47 | set(MAYA_INSTALL_BASE_DEFAULT /usr/autodesk) 48 | set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fPIC") 49 | if(MAYA_VERSION LESS 2016) 50 | SET(MAYA_INSTALL_BASE_SUFFIX -x64) 51 | endif() 52 | set(OPENMAYA libOpenMaya.so) 53 | set(MAYA_PLUGIN_EXTENSION ".so") 54 | endif() 55 | 56 | set(MAYA_INSTALL_BASE_PATH ${MAYA_INSTALL_BASE_DEFAULT} CACHE STRING 57 | "Root path containing your maya installations, e.g. /usr/autodesk or /Applications/Autodesk/") 58 | 59 | set(MAYA_LOCATION ${MAYA_INSTALL_BASE_PATH}/maya${MAYA_VERSION}${MAYA_INSTALL_BASE_SUFFIX}) 60 | 61 | # Maya library directory 62 | find_path(MAYA_LIBRARY_DIR ${OPENMAYA} 63 | PATHS 64 | ${MAYA_LOCATION} 65 | $ENV{MAYA_LOCATION} 66 | $ENV{MAYA_DEVKIT_LOCATION} 67 | PATH_SUFFIXES 68 | "${MAYA_LIB_SUFFIX}/" 69 | DOC "Maya library path" 70 | ) 71 | 72 | # Maya include directory 73 | find_path(MAYA_INCLUDE_DIR maya/MFn.h 74 | PATHS 75 | ${MAYA_LOCATION} 76 | $ENV{MAYA_LOCATION} 77 | $ENV{MAYA_DEVKIT_LOCATION} 78 | PATH_SUFFIXES 79 | "${MAYA_INC_SUFFIX}/" 80 | DOC "Maya include path" 81 | ) 82 | 83 | # Maya libraries 84 | if(WIN32) 85 | # Windows 86 | set(_MAYA_LIBRARIES OpenMaya OpenMayaAnim OpenMayaFX OpenMayaRender OpenMayaUI Foundation clew OpenMayalib OpenMaya AnimSlice DeformSlice Modifiers DynSlice KinSlice ModelSlice NurbsSlice PolySlice ProjectSlice Image Shared Translators DataModel RenderModel NurbsEngine DependEngine CommandEngine Foundation IMFbase 87 | ) 88 | 89 | elseif(APPLE) 90 | # Apple 91 | set(_MAYA_LIBRARIES OpenMaya OpenMayaAnim OpenMayaFX OpenMayaRender OpenMayaUI Foundation clew OpenMayalib OpenMaya AnimSlice DeformSlice Modifiers DynSlice KinSlice ModelSlice NurbsSlice PolySlice ProjectSlice Image Shared Translators DataModel RenderModel NurbsEngine DependEngine CommandEngine Foundation IMFbase 92 | ) 93 | 94 | else() 95 | # Linux 96 | set(_MAYA_LIBRARIES OpenMaya OpenMayaAnim OpenMayaFX OpenMayaRender OpenMayaUI Foundation clew OpenMayalib OpenMaya AnimSlice DeformSlice Modifiers DynSlice KinSlice ModelSlice NurbsSlice PolySlice ProjectSlice Image Shared Translators DataModel RenderModel NurbsEngine DependEngine CommandEngine Foundation IMFbase m dl 97 | ) 98 | endif() 99 | 100 | foreach(MAYA_LIB ${_MAYA_LIBRARIES}) 101 | find_library(MAYA_${MAYA_LIB}_LIBRARY NAMES ${MAYA_LIB} PATHS ${MAYA_LIBRARY_DIR} 102 | NO_DEFAULT_PATH) 103 | if (MAYA_${MAYA_LIB}_LIBRARY) 104 | set(MAYA_LIBRARIES ${MAYA_LIBRARIES} ${MAYA_${MAYA_LIB}_LIBRARY}) 105 | endif() 106 | endforeach() 107 | 108 | if (APPLE AND ${CMAKE_CXX_COMPILER_ID} MATCHES "Clang") 109 | # Clang and Maya needs to use libstdc++ 110 | set(MAYA_CXX_FLAGS "-std=c++0x -stdlib=libstdc++") 111 | endif() 112 | 113 | include(FindPackageHandleStandardArgs) 114 | find_package_handle_standard_args(Maya DEFAULT_MSG MAYA_INCLUDE_DIR MAYA_LIBRARIES) 115 | 116 | function(MAYA_PLUGIN _target) 117 | if (WIN32) 118 | set_target_properties(${_target} PROPERTIES 119 | LINK_FLAGS "/export:initializePlugin /export:uninitializePlugin" 120 | ) 121 | endif() 122 | set_target_properties(${_target} PROPERTIES 123 | COMPILE_DEFINITIONS "${MAYA_COMPILE_DEFINITIONS}" 124 | PREFIX "" 125 | SUFFIX ${MAYA_PLUGIN_EXTENSION}) 126 | endfunction() 127 | -------------------------------------------------------------------------------- /readme.md: -------------------------------------------------------------------------------- 1 | # Readme 2 | 3 | This is the readme for the **Callback Node Example** Maya plugin. 4 | 5 | # About 6 | 7 | This is an example of how to create a custom node that handles installation of a 8 | callback onto a rig without having explicit connections in the dependency graph. 9 | 10 | You can view the full tutorial that goes over creating this node step-by-step [here](https://sonictk.github.io/maya_node_callback_example/). 11 | 12 | ## Building 13 | 14 | ### Requirements 15 | 16 | * Maya 2016 (and above) needs to be installed in order to link to the libraries. 17 | * You will also need the devkit headers, which are available from the official 18 | Autodesk Github repository. 19 | * CMake 2.8.11 and higher is required for building. 20 | 21 | ### Instructions for building with CMake 22 | 23 | * Create a ``build`` directory and navigate to it. 24 | * Run ``cmake ../ -DCMAKE_BUILD_TYPE=Release`` and then ``cmake --build . 25 | --config Release --target install``. The binaries should be installed in the 26 | ``bin`` folder. 27 | 28 | ## Sample code 29 | 30 | In MEL: 31 | 32 | ``` 33 | file -f -newFile; 34 | unloadPlugin "callbackNodeExample"; 35 | loadPlugin "c:/Users/sonictk/Git/experiments/maya_node_callback_example/build/Debug/callbackNodeExample.mll"; 36 | 37 | createNode "transform"; 38 | applyCallback -n "transform1"; 39 | ``` 40 | 41 | # Credits 42 | 43 | Siew Yi Liang (a.k.a **sonictk**) 44 | -------------------------------------------------------------------------------- /src/apply_callback_command.cpp: -------------------------------------------------------------------------------- 1 | #include "apply_callback_command.h" 2 | #include "callback_node.h" 3 | #include 4 | #include 5 | #include 6 | #include 7 | #include 8 | 9 | 10 | const char *flagSelListLongName = "-node"; 11 | const char *flagSelListShortName = "-n"; 12 | 13 | const char *flagHelpLongName = "-help"; 14 | const char *flagHelpShortName = "-h"; 15 | 16 | const char *helpText = "This command will setup a callback on a given node.\n" 17 | "Usage:\n applyCallback [options]\n" 18 | "Options:\n" 19 | "-h / -help Prints this message.\n\n" 20 | "-n / -node The name of the node to setup the callback example for.\n\n"; 21 | 22 | const MString ApplyCallbackCommand::kCOMMAND_NAME = "applyCallback"; 23 | 24 | 25 | void *ApplyCallbackCommand::creator() 26 | { 27 | return new ApplyCallbackCommand(); 28 | } 29 | 30 | 31 | MSyntax ApplyCallbackCommand::newSyntax() 32 | { 33 | MSyntax syntax; 34 | syntax.addFlag(flagHelpShortName, flagHelpLongName); 35 | syntax.addFlag(flagSelListShortName, flagSelListLongName, MSyntax::kSelectionItem); 36 | syntax.enableQuery(false); 37 | syntax.enableEdit(false); 38 | syntax.useSelectionAsDefault(true); 39 | 40 | return syntax; 41 | } 42 | 43 | 44 | MStatus ApplyCallbackCommand::parseArgs(const MArgList &args) 45 | { 46 | MStatus result; 47 | MArgDatabase argDb(syntax(), args, &result); 48 | CHECK_MSTATUS_AND_RETURN_IT(result); 49 | 50 | if (argDb.isFlagSet(flagHelpShortName)) { 51 | displayInfo(helpText); 52 | flagHelpSpecified = true; 53 | return MStatus::kSuccess; 54 | } else { 55 | flagHelpSpecified = false; 56 | } 57 | 58 | if (argDb.isFlagSet(flagSelListShortName)) { 59 | argDb.getFlagArgument(flagSelListShortName, 0, flagSelList); 60 | } 61 | 62 | return result; 63 | } 64 | 65 | 66 | MStatus ApplyCallbackCommand::doIt(const MArgList &args) 67 | { 68 | setCommandString(ApplyCallbackCommand::kCOMMAND_NAME); 69 | clearResult(); 70 | 71 | MStatus result = parseArgs(args); 72 | CHECK_MSTATUS_AND_RETURN_IT(result); 73 | 74 | if (this->flagHelpSpecified == true) { 75 | return MStatus::kSuccess; 76 | } 77 | 78 | return redoIt(); 79 | } 80 | 81 | 82 | MStatus ApplyCallbackCommand::redoIt() 83 | { 84 | MStatus result; 85 | if (flagSelList.length() != 1) { 86 | MGlobal::displayError("You need to select a single node to apply the callback to!"); 87 | return MStatus::kInvalidParameter; 88 | } 89 | 90 | if (doesCallbackNodeAlreadyExist() == true) { 91 | MGlobal::displayError("The feature already exists! You need to delete the existing callback node first!"); 92 | return MStatus::kFailure; 93 | } 94 | 95 | MObject callbackNode = dgMod.createNode(CallbackNode::kNODE_ID, &result); 96 | CHECK_MSTATUS_AND_RETURN_IT(result); 97 | result = dgMod.doIt(); 98 | CHECK_MSTATUS_AND_RETURN_IT(result); 99 | 100 | MFnDependencyNode fnNode(callbackNode); 101 | MPlug callbackNodeMsgPlug = fnNode.findPlug(CallbackNode::kIN_TRANSFORM_ATTR_NAME, 102 | false, 103 | &result); 104 | CHECK_MSTATUS_AND_RETURN_IT(result); 105 | 106 | MObject transform; 107 | result = flagSelList.getDependNode(0, transform); 108 | CHECK_MSTATUS_AND_RETURN_IT(result); 109 | if (!transform.hasFn(MFn::kDependencyNode)) { 110 | MGlobal::displayError("The object specified is not a valid DG node!"); 111 | return MStatus::kInvalidParameter; 112 | } 113 | result = fnNode.setObject(transform); 114 | CHECK_MSTATUS_AND_RETURN_IT(result); 115 | if (!fnNode.hasAttribute(CallbackNode::kMSG_CXN_ATTR_NAME)) { 116 | MFnMessageAttribute fnMsgAttr; 117 | MObject msgAttr = fnMsgAttr.create(CallbackNode::kMSG_CXN_ATTR_NAME, 118 | CallbackNode::kMSG_CXN_ATTR_NAME, 119 | &result); 120 | CHECK_MSTATUS_AND_RETURN_IT(result); 121 | fnNode.addAttribute(msgAttr); 122 | } 123 | MDGModifier dgModCxn; 124 | MPlug msgPlug = fnNode.findPlug(CallbackNode::kMSG_CXN_ATTR_NAME, false, &result); 125 | CHECK_MSTATUS_AND_RETURN_IT(result); 126 | result = dgModCxn.connect(msgPlug, callbackNodeMsgPlug); 127 | CHECK_MSTATUS_AND_RETURN_IT(result); 128 | dgModCxn.doIt(); 129 | 130 | return result; 131 | } 132 | 133 | 134 | MStatus ApplyCallbackCommand::undoIt() 135 | { 136 | dgMod.undoIt(); 137 | return MStatus::kSuccess; 138 | } 139 | 140 | 141 | bool ApplyCallbackCommand::isUndoable() const 142 | { 143 | if (flagHelpSpecified == true) { 144 | return false; 145 | } else { 146 | return true; 147 | } 148 | } 149 | -------------------------------------------------------------------------------- /src/apply_callback_command.h: -------------------------------------------------------------------------------- 1 | #ifndef APPLY_CALLBACK_COMMAND_H 2 | #define APPLY_CALLBACK_COMMAND_H 3 | 4 | 5 | #include 6 | #include 7 | #include 8 | #include 9 | 10 | 11 | class ApplyCallbackCommand : public MPxCommand 12 | { 13 | public: 14 | /** 15 | * This function returns a new instance of the command. 16 | * 17 | * @return A new instance of this command. 18 | */ 19 | static void *creator(); 20 | 21 | /** 22 | * This method parses the arguments that were given to the command and stores 23 | * it in local class data. It finally calls ``redoIt`` to implement the actual 24 | * command functionality. 25 | * 26 | * @param args The arguments that were passed to the command. 27 | * @return The status code. 28 | */ 29 | MStatus doIt(const MArgList &args); 30 | 31 | /** 32 | * This method implements the actual functionality of the command. It is also 33 | * called when the user elects to perform an interactive redo of the command. 34 | * 35 | * @return The status code. 36 | */ 37 | MStatus redoIt(); 38 | 39 | /** 40 | * This method is called when the user performs an undo of the command. It 41 | * restores the scene to its earlier state before the command was run. 42 | * 43 | * @return The status code. 44 | */ 45 | MStatus undoIt(); 46 | 47 | /** 48 | * This method is used to specify whether or not the command is undoable. 49 | * 50 | * @return ``true`` if the command is undo-able, ``false`` otherwise. 51 | * Should only return ``true`` when the command is executed in 52 | * non-query mode. 53 | */ 54 | bool isUndoable() const; 55 | 56 | /** 57 | * This static method returns the syntax object for this command. 58 | * 59 | * @return The syntax object set up for this command. 60 | */ 61 | static MSyntax newSyntax(); 62 | 63 | /// The name of the command that is meant to be run. 64 | static const MString kCOMMAND_NAME; 65 | 66 | /** 67 | * This method parses the given arguments to the command and stores the 68 | * results in local class data. 69 | * 70 | * @param args The arguments that were passed to the command. 71 | * @return The status code. 72 | */ 73 | MStatus parseArgs(const MArgList &args); 74 | 75 | /// Storage for the flag arguments that will be passed into the command. 76 | bool flagHelpSpecified = false; 77 | MSelectionList flagSelList; 78 | 79 | /// Storage for the operations that this command performs on the DG so that we 80 | /// can undo them if necessary. 81 | MDGModifier dgMod; 82 | }; 83 | 84 | 85 | #endif /* APPLY_CALLBACK_COMMAND_H */ 86 | -------------------------------------------------------------------------------- /src/callback_node.cpp: -------------------------------------------------------------------------------- 1 | #include "callback_node.h" 2 | #include 3 | #include 4 | #include 5 | #include 6 | #include 7 | #include 8 | #include 9 | #include 10 | #include 11 | #include 12 | #include 13 | 14 | using std::cerr; 15 | using std::strstr; 16 | using std::sin; 17 | using std::cos; 18 | 19 | const MTypeId CallbackNode::kNODE_ID(0x0007ffff); 20 | const MString CallbackNode::kNODE_NAME = "callbackNodeExample"; 21 | const char *CallbackNode::kIN_TRANSFORM_ATTR_NAME = "transform"; 22 | const char *CallbackNode::kMSG_CXN_ATTR_NAME = "callback"; 23 | const char *CallbackNode::kTOGGLE_ATTR_NAME = "toggle"; 24 | 25 | MObject CallbackNode::inTransformAttr; 26 | MObject CallbackNode::toggleAttr; 27 | 28 | MCallbackIdArray CallbackNode::callbacks; 29 | 30 | 31 | bool doesCallbackNodeAlreadyExist() 32 | { 33 | MStatus status; 34 | MItDependencyNodes itDn(MFn::kPluginDependNode, &status); 35 | if (status != MStatus::kSuccess) { 36 | cerr << "Error when attempting to create iterator!\n"; 37 | return false; 38 | } 39 | MFnDependencyNode fnNode; 40 | for (; !itDn.isDone(); itDn.next()) { 41 | MObject curNode = itDn.thisNode(); 42 | fnNode.setObject(curNode); 43 | if (fnNode.typeId() == CallbackNode::kNODE_ID) { 44 | return true; 45 | } 46 | } 47 | return false; 48 | } 49 | 50 | 51 | MStatus uninstallCallback() 52 | { 53 | MStatus status = MMessage::removeCallbacks(CallbackNode::callbacks); 54 | MGlobal::displayInfo("Removed feature!"); 55 | return status; 56 | } 57 | 58 | 59 | void uninstallCallback(MObject &node, void *data) 60 | { 61 | uninstallCallback(); 62 | } 63 | 64 | 65 | /** 66 | * This callback is triggered whenever an attribute changes on the callback node. 67 | * It is responsible for setting up the example features in the scene. 68 | * 69 | * @param msg The message indicating why this callback was triggered. 70 | * @param plug The plug representing the attribute that changed. 71 | * @param otherPlug Unused argument. 72 | * @param data Unused argument. 73 | */ 74 | void featureCallback(MNodeMessage::AttributeMessage msg, 75 | MPlug &plug, 76 | MPlug &otherPlug, 77 | void *data) 78 | { 79 | if (msg != (MNodeMessage::kAttributeSet|MNodeMessage::kIncomingDirection)) { 80 | return; 81 | } 82 | const char *plugName = plug.partialName(0,0,0,0,0,1).asChar(); 83 | if (strstr("translateX", plugName) == NULL) { 84 | return; 85 | } 86 | MStatus status; 87 | MPlug transformPlug = plug.parent(&status); 88 | if (status != MStatus::kSuccess) { 89 | return; 90 | } 91 | double xVal = plug.asDouble(); 92 | MPlug transformYPlug = transformPlug.child(1, &status); 93 | if (status != MStatus::kSuccess) { 94 | return; 95 | } 96 | MPlug transformZPlug = transformPlug.child(2, &status); 97 | if (status != MStatus::kSuccess) { 98 | return; 99 | } 100 | // NOTE: (sonictk) Here we make the node go in a spiral motion as an example 101 | double newYVal = sin(xVal); 102 | double newZVal = cos(transformZPlug.asDouble() + xVal); 103 | transformYPlug.setDouble(newYVal); 104 | transformZPlug.setDouble(newZVal); 105 | } 106 | 107 | 108 | /** 109 | * This callback is triggered whenever an attribute changes on the callback node. 110 | * It is responsible for setting up the example features in the scene. 111 | * 112 | * @param msg The message indicating why this callback was triggered. 113 | * @param plug The plug representing the attribute that changed. 114 | * @param otherPlug Unused argument. 115 | * @param data Unused argument. 116 | */ 117 | void installCallback(MNodeMessage::AttributeMessage msg, 118 | MPlug &plug, 119 | MPlug &otherPlug, 120 | void *data) 121 | { 122 | if (msg == (MNodeMessage::kConnectionBroken| 123 | MNodeMessage::kIncomingDirection| 124 | MNodeMessage::kOtherPlugSet)) { 125 | uninstallCallback(); 126 | } 127 | if (msg != (MNodeMessage::kConnectionMade| 128 | MNodeMessage::kIncomingDirection| 129 | MNodeMessage::kOtherPlugSet)) { 130 | return; 131 | } 132 | // NOTE: (sonictk) We check if the node has its message connection connected 133 | // first to determine if we should install the real callback onto that node 134 | MObject callbackNode = plug.node(); 135 | MFnDependencyNode fnNode(callbackNode); 136 | MPlug cxnPlug = fnNode.findPlug(CallbackNode::kIN_TRANSFORM_ATTR_NAME); 137 | MPlugArray connectedPlugs; 138 | cxnPlug.connectedTo(connectedPlugs, true, false); 139 | if (connectedPlugs.length() != 1) { 140 | return; 141 | } 142 | MObject transformNode = connectedPlugs[0].node(); 143 | if (!transformNode.hasFn(MFn::kTransform)) { 144 | return; 145 | } 146 | // NOTE: (sonictk) Install the callback onto the other node and add it to the 147 | // registry of callbacks to track 148 | MStatus status; 149 | MCallbackId featureCallbackId = MNodeMessage::addAttributeChangedCallback(transformNode, 150 | featureCallback, 151 | NULL, 152 | &status); 153 | if (status != MStatus::kSuccess) { 154 | return; 155 | } 156 | CallbackNode::callbacks.append(featureCallbackId); 157 | MGlobal::displayInfo("Feature installed!"); 158 | } 159 | 160 | 161 | void *CallbackNode::creator() 162 | { 163 | return new CallbackNode(); 164 | } 165 | 166 | 167 | MStatus CallbackNode::initialize() 168 | { 169 | MStatus result; 170 | 171 | MFnMessageAttribute fnMsgAttr; 172 | inTransformAttr = fnMsgAttr.create(CallbackNode::kIN_TRANSFORM_ATTR_NAME, 173 | CallbackNode::kIN_TRANSFORM_ATTR_NAME, 174 | &result); 175 | CHECK_MSTATUS_AND_RETURN_IT(result); 176 | 177 | MFnNumericAttribute fnNumAttr; 178 | toggleAttr = fnNumAttr.create(CallbackNode::kTOGGLE_ATTR_NAME, 179 | CallbackNode::kTOGGLE_ATTR_NAME, 180 | MFnNumericData::kBoolean, 181 | 0, 182 | &result); 183 | CHECK_MSTATUS_AND_RETURN_IT(result); 184 | fnNumAttr.setKeyable(true); 185 | 186 | addAttribute(inTransformAttr); 187 | addAttribute(toggleAttr); 188 | 189 | return result; 190 | } 191 | 192 | 193 | void CallbackNode::postConstructor() 194 | { 195 | MStatus status; 196 | MObject thisNode = thisMObject(); 197 | 198 | MCallbackId installId = MNodeMessage::addAttributeChangedCallback(thisNode, 199 | installCallback, 200 | NULL, 201 | &status); 202 | if (status != MStatus::kSuccess) { 203 | MGlobal::displayError("Unable to install example feature!"); 204 | uninstallCallback(); 205 | return; 206 | } 207 | callbacks.append(installId); 208 | MNodeMessage::addNodePreRemovalCallback(thisNode, 209 | uninstallCallback, 210 | NULL, 211 | &status); 212 | if (status != MStatus::kSuccess) { 213 | MGlobal::displayError("Unable to install example feature!"); 214 | uninstallCallback(); 215 | return; 216 | } 217 | } 218 | -------------------------------------------------------------------------------- /src/callback_node.h: -------------------------------------------------------------------------------- 1 | /** 2 | * @brief This is a defintion of a Maya node that demonstrates a method of 3 | * installing callbacks onto the scene during its lifetime. 4 | */ 5 | #ifndef CALLBACK_NODE_H 6 | #define CALLBACK_NODE_H 7 | 8 | 9 | #include 10 | #include 11 | #include 12 | #include 13 | #include 14 | #include 15 | #include 16 | #include 17 | 18 | 19 | /** 20 | * This function checks if a callback node already exists in the current Maya session. 21 | * 22 | * @return ``true`` if the node already exists, ``false`` otherwise. 23 | */ 24 | bool doesCallbackNodeAlreadyExist(); 25 | 26 | 27 | /** 28 | * This function will handle cleanup of all callbacks that were installed for the 29 | * example feature to work. 30 | * 31 | * @return ``MStatus::kSuccess`` if the feature was successfully removed. 32 | */ 33 | MStatus uninstallCallback(); 34 | 35 | 36 | /** 37 | * This callback is triggered whenever the callback node is deleted. It is responsible 38 | * for handling un-installation of all the callbacks that were initially set up by 39 | * this node in the current Maya scene. 40 | * 41 | * @param node Ununsed argument. 42 | * @param data Unused argument. 43 | */ 44 | void uninstallCallback(MObject &node, void *data); 45 | 46 | 47 | /// This is a dependency node that will install a callback during its lifetime. 48 | class CallbackNode : MPxNode 49 | { 50 | public: 51 | /** 52 | * The creator function. 53 | * 54 | * @return A new instance of the node. 55 | */ 56 | static void *creator(); 57 | 58 | /** 59 | * This is the initialization of the node. It creates the attributes and sets up 60 | * their dependencies. 61 | * 62 | * @return The status code. 63 | */ 64 | static MStatus initialize(); 65 | 66 | /** 67 | * This function is run when the node is first created. It is responsible for 68 | * setting up all the necessary callbacks. 69 | * 70 | */ 71 | virtual void postConstructor(); 72 | 73 | static const MTypeId kNODE_ID; /// The unique ID that identifies this node. 74 | static const MString kNODE_NAME; /// The name of the DG node. 75 | 76 | static const char *kIN_TRANSFORM_ATTR_NAME; /// The name of the message connection attribute on the callback node. 77 | static const char *kMSG_CXN_ATTR_NAME; /// The name of the message connection attribute on the transform node. 78 | static const char *kTOGGLE_ATTR_NAME; /// The name of the attribute to toggle the feature. 79 | 80 | static MObject inTransformAttr; 81 | static MObject toggleAttr; 82 | 83 | static MCallbackIdArray callbacks; /// Storage for the callbacks registered by this node. 84 | }; 85 | 86 | 87 | #endif /* CALLBACK_NODE_H */ 88 | -------------------------------------------------------------------------------- /src/plugin_main.cpp: -------------------------------------------------------------------------------- 1 | #include "plugin_main.h" 2 | #include 3 | 4 | const char *kAUTHOR = "Siew Yi Liang"; 5 | const char *kVERSION = "1.0.0"; 6 | const char *kREQUIRED_API_VERSION = "Any"; 7 | 8 | 9 | MStatus initializePlugin(MObject obj) 10 | { 11 | MStatus status; 12 | MFnPlugin plugin(obj, kAUTHOR, kVERSION, kREQUIRED_API_VERSION); 13 | 14 | status = plugin.registerNode(CallbackNode::kNODE_NAME, 15 | CallbackNode::kNODE_ID, 16 | &CallbackNode::creator, 17 | &CallbackNode::initialize, 18 | MPxNode::kDependNode); 19 | CHECK_MSTATUS_AND_RETURN_IT(status); 20 | 21 | status = plugin.registerCommand(ApplyCallbackCommand::kCOMMAND_NAME, 22 | ApplyCallbackCommand::creator, 23 | ApplyCallbackCommand::newSyntax); 24 | CHECK_MSTATUS_AND_RETURN_IT(status); 25 | 26 | return status; 27 | } 28 | 29 | 30 | MStatus uninitializePlugin(MObject obj) 31 | { 32 | MFnPlugin plugin(obj); 33 | MStatus status; 34 | uninstallCallback(); 35 | status = plugin.deregisterNode(CallbackNode::kNODE_ID); 36 | CHECK_MSTATUS_AND_RETURN_IT(status); 37 | 38 | status = plugin.deregisterCommand(ApplyCallbackCommand::kCOMMAND_NAME); 39 | CHECK_MSTATUS_AND_RETURN_IT(status); 40 | 41 | return status; 42 | } 43 | -------------------------------------------------------------------------------- /src/plugin_main.h: -------------------------------------------------------------------------------- 1 | /** 2 | * @brief This is the declaration of the plugin initalization functions. It is 3 | * responsible for registration of the plugin nodes and all other 4 | * associated types that are available to be loaded in Maya. 5 | */ 6 | #ifndef PLUGIN_MAIN_H 7 | #define PLUGIN_MAIN_H 8 | 9 | 10 | #include "callback_node.cpp" 11 | #include "apply_callback_command.cpp" 12 | 13 | 14 | /** 15 | * This is the entry point of the plugin. It is run when the plugin is first 16 | * loaded into Maya. 17 | * 18 | * @param obj The internal Maya object containing Maya private information 19 | * about the plug-in. 20 | * 21 | * @return The status code. 22 | */ 23 | MStatus initializePlugin(MObject obj); 24 | 25 | 26 | /** 27 | * The teardown function of the plugin. This function unregisters all dependency 28 | * nodes and other services that the plug-in registers during initialization. 29 | * 30 | * @param obj The internal Maya object containing Maya private information 31 | * about the plug-in. 32 | * 33 | * @return The status code. 34 | */ 35 | MStatus uninitializePlugin(MObject obj); 36 | 37 | 38 | #endif /* PLUGIN_MAIN_H */ 39 | --------------------------------------------------------------------------------