├── LICENSE ├── README.md ├── RTRenderer.js └── Tutorial (Simple).md /LICENSE: -------------------------------------------------------------------------------- 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. By contrast, 15 | the GNU General Public License is intended to guarantee your freedom to 16 | share and change all versions of a program--to make sure it remains free 17 | software for all its users. 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It is safest 630 | to attach them to the start of each source file to most effectively 631 | state the exclusion of warranty; and each file should have at least 632 | the "copyright" line and a pointer to where the full notice is found. 633 | 634 | 635 | Copyright (C) 636 | 637 | This program is free software: you can redistribute it and/or modify 638 | it under the terms of the GNU General Public License as published by 639 | the Free Software Foundation, either version 3 of the License, or 640 | (at your option) any later version. 641 | 642 | This program is distributed in the hope that it will be useful, 643 | but WITHOUT ANY WARRANTY; without even the implied warranty of 644 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 645 | GNU General Public License for more details. 646 | 647 | You should have received a copy of the GNU General Public License 648 | along with this program. If not, see . 649 | 650 | Also add information on how to contact you by electronic and paper mail. 651 | 652 | If the program does terminal interaction, make it output a short 653 | notice like this when it starts in an interactive mode: 654 | 655 | Copyright (C) 656 | This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'. 657 | This is free software, and you are welcome to redistribute it 658 | under certain conditions; type `show c' for details. 659 | 660 | The hypothetical commands `show w' and `show c' should show the appropriate 661 | parts of the General Public License. Of course, your program's commands 662 | might be different; for a GUI interface, you would use an "about box". 663 | 664 | You should also get your employer (if you work as a programmer) or school, 665 | if any, to sign a "copyright disclaimer" for the program, if necessary. 666 | For more information on this, and how to apply and follow the GNU GPL, see 667 | . 668 | 669 | The GNU General Public License does not permit incorporating your program 670 | into proprietary programs. If your program is a subroutine library, you 671 | may consider it more useful to permit linking proprietary applications with 672 | the library. If this is what you want to do, use the GNU Lesser General 673 | Public License instead of this License. But first, please read 674 | . 675 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | #Unity Raytraced Renderer 2 | === 3 | ##Usage 4 | Just by simple attaching this script to any camera, the raytraced renderer will perform it's magic, 5 | It is however noteworthy that this was made in Unity 4 and backwards comppatability is not guaranteed. 6 | This works in both indie and pro, with all features, no ristrictions. 7 | All Textures that are to be rendered must have `Read/Write Enabled` Enabled 8 | 9 | ##Settings 10 | I will briefly explain each setting of the script 11 | 12 | `Real Time` Simple enough, if you want the renderer to do more than 1 render, check this 13 | 14 | `AutoGenerateColliders` Unless you've read the code and know what this dies, keep this one on 15 | 16 | `Smooth Edges` This will make round edges seem rounf and not jagged. It does however decrease performance quite a bit. 17 | 18 | `Single material Only` If your meshes have more than 1 material, and you want them to render, tick this, otherwise it's just a performance boost ;) 19 | 20 | `Use Lighting` Without this everything will be rendered as if it was completely lit on all sides. 21 | 22 | `Resolution` The multiplyer of the resolution to render at. If you have a `100x100` display and it is at `0.1`, it will render at `10x10`. At `2.0` it will render at `200x200`. 23 | 24 | `Max Stack` The maximum number of recursive steps to take. Good numbers: 5-20 25 | 26 | ##Rights 27 | Note that this is a community project. Any commits are welcome! Any feedback is welcome. 28 | I do not care about credit. Tell your friends you made this for all I care :P 29 | Also note that this was started by me: Benproductions1 30 | 31 | ##Contact 32 | If anyone has any questions/comments/remarks feel free to do so on the unity forums page for this project here: 33 | http://forum.unity3d.com/showthread.php?175212 34 | -------------------------------------------------------------------------------- /RTRenderer.js: -------------------------------------------------------------------------------- 1 | /* 2 | This Script was originally created by (me) Benproductions1 3 | Be advised that it is in no way shape or form not permitted to edit this! 4 | This is designed to be a community project, it will always stay that way! 5 | The Github repository can be found here: 6 | https://github.com/Benproductions1/Unity-Raytracer 7 | 8 | I hope you learn something from this project and/or contribute to it :) 9 | 10 | HOW TO USE!! 11 | If your just here to see my work, 12 | I suggest making a new scene, throwing in some objects 13 | Adding this script to the camera and see what happens 14 | 15 | TIP: if your computer is slow, it will have allot of hang time 16 | 17 | TIP: This raytracing uses the CPU, not the GPU 18 | 19 | TIP: Do not try real time raytracing with a resolution of 1 20 | */ 21 | 22 | /* 23 | ---||SETUP||--- 24 | */ 25 | 26 | import System.IO; 27 | 28 | //Raytracer Settings 29 | var RealTime:boolean = true; 30 | var AutoGenerateColliders:boolean = true; 31 | var SmoothEdges:boolean = true; 32 | var SingleMaterialOnly:boolean = false; 33 | var UseLighting:boolean = true; 34 | var resolution:float = 1; 35 | var MaxStack:int = 2; 36 | 37 | //The render texture 38 | @System.NonSerialized 39 | var screen:Texture2D; 40 | 41 | //The shader used for reflections 42 | private var reflectiveShader:Shader; 43 | 44 | //iteration variables 45 | private var x:int; 46 | private var y:int; 47 | 48 | private var light:Light; 49 | private var tris:int[]; 50 | private var tri:int[]; 51 | 52 | private var index:int; 53 | private var index2:int; 54 | private var index3:int; 55 | 56 | //temporary variables 57 | private var ray:Ray; 58 | private var direction:Vector3; 59 | private var normal:Vector3; 60 | 61 | private var tmpFloat:float; 62 | private var tmpFloat2:float; 63 | 64 | private var tmpTex:Texture2D; 65 | private var tmpMat:Material; 66 | 67 | private var tmpMeshFilter:MeshFilter; 68 | private var tmpGameObject:GameObject; 69 | 70 | //List variables for optimisation 71 | private var lights:Light[]; 72 | 73 | //Collision Mask 74 | private var collisionMask:LayerMask = 1 << 31; 75 | 76 | 77 | /* 78 | ---||INITIALISATION||--- 79 | */ 80 | 81 | function Start() { 82 | //If the render texture already exists, destroy it! 83 | if (screen) { 84 | Destroy(screen); 85 | } 86 | 87 | //Create a new texture to render to 88 | screen = new Texture2D(Screen.width*resolution, Screen.height*resolution); 89 | 90 | //Find the reflective shader to use (Specular) 91 | reflectiveShader = Shader.Find("Specular"); 92 | 93 | if (AutoGenerateColliders) { 94 | //Generate Raytrace Colliders (mesh) for all renderers 95 | for (tmpMeshFilter in FindSceneObjectsOfType(typeof MeshFilter) as MeshFilter[]) { 96 | GenerateColliders(tmpMeshFilter); 97 | } 98 | } 99 | 100 | if (!RealTime) { 101 | //Start Single Ray Trace 102 | RayTrace(); 103 | } 104 | } 105 | 106 | 107 | /* 108 | ---||RUNTIME LOOP||--- 109 | */ 110 | 111 | function Update() { 112 | if (RealTime) { 113 | //Try real time ray tracing 114 | RayTrace(); 115 | } 116 | } 117 | 118 | function OnGUI() { 119 | //Draw the rendered image along with an FPS count 120 | GUI.DrawTexture(Rect(0, 0, Screen.width, Screen.height), screen); 121 | GUILayout.Label("fps: " + Mathf.Round(1/Time.smoothDeltaTime)); 122 | } 123 | 124 | //One full raytrace 125 | function RayTrace():void { 126 | //Find all lights and remember them (optimisation) 127 | lights = FindSceneObjectsOfType(typeof Light) as Light[]; 128 | 129 | //Iterate through each pixel 130 | for (x = 0; x < screen.width; x += 1) { 131 | for (y = 0; y < screen.height; y += 1) { 132 | //Trace each pixel and set the return value as the colour 133 | screen.SetPixel(x, y, TracePixel(Vector2(x, y))); 134 | } 135 | } 136 | //Apply changes to the render texture 137 | screen.Apply(); 138 | } 139 | 140 | //Raytrace for one pixel 141 | function TracePixel(pos:Vector2):Color { 142 | //Calculate world position of the pixel and start a single Trace 143 | ray = camera.ScreenPointToRay(Vector3(pos.x/resolution, pos.y/resolution, 0)); 144 | return TraceRay(ray.origin, ray.direction, 0); 145 | } 146 | 147 | //A Single Trace 148 | function TraceRay(origin:Vector3, direction:Vector3, stack:int):Color { 149 | //Set nessesary temporary local variables 150 | var tmpColor:Color; 151 | var hit:RaycastHit; 152 | 153 | //Check Stack Flow and perform Raycast 154 | if (stack < MaxStack && Physics.Raycast(origin, direction, hit, camera.farClipPlane, collisionMask)) { 155 | 156 | //Perform calculations only if we hit a collider with a parent (error handling) 157 | if (hit.collider && hit.collider.transform.parent) { 158 | //if we have multiple materials and we are checking for multiple materials 159 | if (hit.collider.transform.parent.GetComponent(MeshFilter).mesh.subMeshCount > 1 && !SingleMaterialOnly) { 160 | //find material from triangle index 161 | tmpMat = hit.collider.transform.parent.renderer.materials[GetMatFromTrisInMesh(hit.collider.transform.parent.GetComponent(MeshFilter).mesh, hit.triangleIndex)]; 162 | } 163 | else { 164 | //set material to primary material 165 | tmpMat = hit.collider.transform.parent.renderer.material; 166 | } 167 | 168 | //if the material has a texture 169 | if (tmpMat.mainTexture) { 170 | //set the colour to that of the texture coord of the raycast hit 171 | tmpColor = (tmpMat.mainTexture as Texture2D).GetPixelBilinear(hit.textureCoord.x, hit.textureCoord.y); 172 | } 173 | else { 174 | //set the colour to the colour of the material 175 | tmpColor = tmpMat.color; 176 | } 177 | 178 | //Transparent pixel, trace again and add on to colour 179 | if (tmpColor.a < 1) { 180 | tmpColor *= tmpColor.a; 181 | tmpColor += (1-tmpColor.a)*TraceRay(hit.point-hit.normal*0.01, direction, stack+1); 182 | } 183 | 184 | //Surface is reflective, trace reflection and add on to colour 185 | if (tmpMat.shader == reflectiveShader) { 186 | tmpFloat = tmpColor.a*tmpMat.GetFloat("_Shininess"); 187 | tmpColor += tmpFloat*TraceRay(hit.point+hit.normal*0.0001, Vector3.Reflect(direction, hit.normal), stack+1); 188 | } 189 | 190 | //Calculate lighting 191 | if (UseLighting) { 192 | //With smooth edges 193 | if (SmoothEdges) { 194 | tmpColor *= TraceLight(hit.point+hit.normal*0.0001, InterpolateNormal(hit.point, hit.normal, hit.collider.transform.parent.GetComponent(MeshFilter).mesh, hit.triangleIndex, hit.transform)); 195 | } 196 | //Without smooth edges 197 | else { 198 | tmpColor *= TraceLight(hit.point+hit.normal*0.0001, hit.normal); 199 | } 200 | } 201 | 202 | tmpColor.a = 1; 203 | return tmpColor; 204 | } 205 | else { 206 | //Return Error colour on wierd error 207 | return Color.red; 208 | } 209 | } 210 | else { 211 | //Render Skybox if present, else just blue 212 | if (RenderSettings.skybox) { 213 | //Perform A Skybox Trace 214 | tmpColor = SkyboxTrace(direction, RenderSettings.skybox); 215 | 216 | //Replace alpha with White colour 217 | //for some reason nessesary 218 | tmpColor += Color.white*(1-tmpColor.a)/10; 219 | tmpColor.a = 1; 220 | 221 | return tmpColor; 222 | } 223 | else { 224 | return Color.blue; 225 | } 226 | } 227 | } 228 | 229 | //Convert a direction to a pixel of a cubemap (used only for skyboxes) 230 | function SkyboxTrace(direction:Vector3, skybox:Material):Color { 231 | //Funky stuff I still don't quite get 232 | //If you can explain this, please add comments 233 | 234 | if (Mathf.Abs(direction.x) > Mathf.Abs(direction.y)) { 235 | if (Mathf.Abs(direction.x) > Mathf.Abs(direction.z)) { 236 | if (direction.x < 0) { 237 | return (skybox.GetTexture("_LeftTex") as Texture2D).GetPixelBilinear((-direction.z/-direction.x+1)/2, (direction.y/-direction.x+1)/2); 238 | } 239 | else{ 240 | return (skybox.GetTexture("_RightTex") as Texture2D).GetPixelBilinear((direction.z/direction.x+1)/2, (direction.y/direction.x+1)/2); 241 | } 242 | } 243 | else{ 244 | if (direction.z < 0) { 245 | return (skybox.GetTexture("_BackTex") as Texture2D).GetPixelBilinear((direction.x/-direction.z+1)/2, (direction.y/-direction.z+1)/2); 246 | } 247 | else{ 248 | return (skybox.GetTexture("_FrontTex") as Texture2D).GetPixelBilinear((-direction.x/direction.z+1)/2, (direction.y/direction.z+1)/2); 249 | } 250 | } 251 | } 252 | else if (Mathf.Abs(direction.y) > Mathf.Abs(direction.z)){ 253 | if (direction.y < 0) { 254 | return (skybox.GetTexture("_DownTex") as Texture2D).GetPixelBilinear((-direction.x/-direction.y+1)/2, (direction.z/-direction.y+1)/2); 255 | } 256 | else{ 257 | return (skybox.GetTexture("_UpTex") as Texture2D).GetPixelBilinear((-direction.x/direction.y+1)/2, (-direction.z/direction.y+1)/2); 258 | } 259 | } 260 | else{ 261 | if (direction.z < 0) { 262 | return (skybox.GetTexture("_BackTex") as Texture2D).GetPixelBilinear((direction.x/-direction.z+1)/2, (direction.y/-direction.z+1)/2); 263 | } 264 | else{ 265 | return (skybox.GetTexture("_FrontTex") as Texture2D).GetPixelBilinear((-direction.x/direction.z+1)/2, (direction.y/direction.z+1)/2); 266 | } 267 | } 268 | } 269 | 270 | //Returns the material index of a mesh a triangle is using 271 | //Acctually it returns the index of the submesh the triangle is in 272 | function GetMatFromTrisInMesh(mesh:Mesh, trisIndex:int):int { 273 | //get the triangel from the triangle index 274 | tri = [mesh.triangles[trisIndex*3], mesh.triangles[trisIndex*3+1], mesh.triangles[trisIndex*3+2]]; 275 | 276 | //Iterate through all submeshes, each submesh has a different material of the same index as the submesh 277 | for (index = 0; index < mesh.subMeshCount; index++) { 278 | //Get submesh trianges 279 | tris = mesh.GetTriangles(index); 280 | //Iterate through all triangles 281 | for (index2 = 0; index2 < tris.length; index2 += 3) { 282 | //Find the same triangle and return the index of the submesh it is in 283 | if (tris[index2] == tri[0] && tris[index2+1] == tri[1] && tris[index2+2] == tri[2]) { 284 | return index; 285 | } 286 | } 287 | } 288 | } 289 | 290 | //Interpolates between the 3 normals of a triangle given the point 291 | function InterpolateNormal(point:Vector3, normal:Vector3, mesh:Mesh, trisIndex:int, trans:Transform):Vector3 { 292 | //find the indexes of each verticie of the triange 293 | index = mesh.triangles[trisIndex*3]; 294 | index2 = mesh.triangles[trisIndex*3+1]; 295 | index3 = mesh.triangles[trisIndex*3+2]; 296 | 297 | //temporary variable used for re-arrenement 298 | var tmpIndex:int; 299 | 300 | //Find the distance between each verticie and the point 301 | var d1:float = Vector3.Distance(mesh.vertices[index], point); 302 | var d2:float = Vector3.Distance(mesh.vertices[index2], point); 303 | var d3:float = Vector3.Distance(mesh.vertices[index3], point); 304 | 305 | //compare and rearrange the verticie index so that index is the one furthest away from the point 306 | if (d2 > d1 && d2 > d3) { 307 | tmpIndex = index; 308 | index = index2; 309 | index2 = tmpIndex; 310 | } 311 | else if (d3 > d1 && d3 > d2) { 312 | tmpIndex = index; 313 | index = index3; 314 | index3 = tmpIndex; 315 | tmpIndex = index2; 316 | index2 = index3; 317 | index3 = tmpIndex; 318 | } 319 | 320 | //Find the point along the line between the 2 other verticies that the ray from the furthest verticies through the point intersects 321 | //Using Plane raycasting 322 | //Generate Plane 323 | var plane:Plane = Plane(trans.TransformPoint(mesh.vertices[index2]), trans.TransformPoint(mesh.vertices[index3])+normal, trans.TransformPoint(mesh.vertices[index3])-normal); 324 | //Renerate Ray 325 | ray = Ray(trans.TransformPoint(mesh.vertices[index]), (point - trans.TransformPoint(mesh.vertices[index])).normalized); 326 | 327 | //Intersect Ray and Plane 328 | if (!plane.Raycast(ray, tmpFloat)) { 329 | //Something went terribly wrong... damn it 330 | Debug.Log("This Shouldn't EVER happen"); 331 | return normal; 332 | } 333 | 334 | //Do the interpolation :D 335 | //If you really wanna see how this works, just google it 336 | //It's too complicated to explain here 337 | var point2:Vector3 = ray.origin+ray.direction*tmpFloat; 338 | var normal2:Vector3 = Vector3.Lerp(trans.TransformDirection(mesh.normals[index2]), trans.TransformDirection(mesh.normals[index3]), Vector3.Distance(trans.TransformPoint(mesh.vertices[index2]), point2)/Vector3.Distance(trans.TransformPoint(mesh.vertices[index2]), trans.TransformPoint(mesh.vertices[index3]))); 339 | var normal3:Vector3 = Vector3.Lerp(normal2, trans.TransformDirection(mesh.normals[index]), Vector3.Distance(point2, point)/Vector3.Distance(point2, trans.TransformPoint(mesh.vertices[index]))); 340 | //return interpolated normal 341 | return normal3; 342 | } 343 | 344 | //Calculate the lighting of a point 345 | function TraceLight(pos:Vector3, normal:Vector3):Color { 346 | //set nessesary temporary provate variables 347 | //set default light to ambient lighting 348 | var tmpColor:Color = RenderSettings.ambientLight; 349 | 350 | //Iterate through all lights in the scene 351 | //lights is computer once per render (optimisation) 352 | for (light in lights) { 353 | //Only calculate lighting if the light is on 354 | if (light.enabled) { 355 | //trace the light and add it to the light colour 356 | tmpColor += LightTrace(light, pos, normal); 357 | } 358 | } 359 | 360 | //return light colour at that point 361 | return tmpColor; 362 | } 363 | 364 | //Trace lighting for one light at one spot 365 | function LightTrace(light:Light, pos:Vector3, normal:Vector3):Color { 366 | var hit:RaycastHit; 367 | 368 | //If light is directional (easy) 369 | //Just trace in the opposite direction 370 | if (light.type == LightType.Directional) { 371 | direction = light.transform.TransformDirection(Vector3.back); 372 | return transparancyTrace(Color(light.intensity, light.intensity, light.intensity)*(1-Quaternion.Angle(Quaternion.identity, Quaternion.FromToRotation(normal, direction))/90), pos, direction, Mathf.Infinity); 373 | } 374 | 375 | //If light is point light (medium) 376 | //Just trace towards it, if within range 377 | //also apply linear falloff according to distance and range 378 | if (light.type == LightType.Point) { 379 | if (Vector3.Distance(pos, light.transform.position) <= light.range) { 380 | direction = (light.transform.position - pos).normalized; 381 | tmpFloat = (light.range-Vector3.Distance(pos, light.transform.position))/light.range*light.intensity; 382 | return transparancyTrace(Color(tmpFloat, tmpFloat, tmpFloat)*(1-Quaternion.Angle(Quaternion.identity, Quaternion.FromToRotation(normal, direction))/90), pos, direction, Vector3.Distance(light.transform.position, pos)); 383 | } 384 | } 385 | 386 | //If light is spot light (Hard) 387 | //Do the same as a point light, but also get the angle from direction towards the light to the opposite direction of the light 388 | //If this angle is more than the spot angle, no light 389 | //else apply linear fall off according to this angle and spot angle 390 | if (light.type == LightType.Spot) { 391 | if (Vector3.Distance(pos, light.transform.position) <= light.range) { 392 | direction = (light.transform.position - pos).normalized; 393 | if (Vector3.Angle(direction, -light.transform.forward) < light.spotAngle) { 394 | tmpFloat = (light.range-Vector3.Distance(pos, light.transform.position))/light.range*light.intensity; 395 | tmpFloat *= 1 - Vector3.Angle(direction, -light.transform.forward)/light.spotAngle; 396 | return transparancyTrace(Color(tmpFloat, tmpFloat, tmpFloat)*(1-Quaternion.Angle(Quaternion.identity, Quaternion.FromToRotation(normal, direction))/90), pos, direction, Vector3.Distance(light.transform.position, pos)); 397 | } 398 | } 399 | } 400 | 401 | //If the light is of any other type, do not calculate any lighting 402 | return Color.black; 403 | } 404 | 405 | //This traces for transparent shadows 406 | //Instead of tracing once to see if an object was hit, it does a RaycastAll 407 | //And Iterates through all objects, gets the pixel colour of that raycast hit 408 | //Then multiples it by the inverse of the alpha of that pixel 409 | function transparancyTrace(col:Color, pos:Vector3, dir:Vector3, dist:float) { 410 | var tmpColor = col; 411 | var hits:RaycastHit[]; 412 | var hit:RaycastHit; 413 | 414 | //Raycast throug everything, returning a list of hits, instead of just the closest 415 | hits = Physics.RaycastAll(pos, dir, dist, collisionMask); 416 | //Iterate through each hit 417 | for (hit in hits) { 418 | //Same as in TraceRay, it gets the pixel colour of that hit point 419 | //So no point in commenting on this 420 | if (hit.collider.transform.parent.GetComponent(MeshFilter).mesh.subMeshCount > 1 && !SingleMaterialOnly) { 421 | tmpMat = hit.collider.transform.parent.renderer.materials[GetMatFromTrisInMesh(hit.collider.transform.parent.GetComponent(MeshFilter).mesh, hit.triangleIndex)]; 422 | } 423 | else { 424 | tmpMat = hit.collider.transform.parent.renderer.material; 425 | } 426 | 427 | //Apply colour transformation according to pixels alpha value 428 | if (tmpMat.mainTexture) { 429 | tmpTex = (tmpMat.mainTexture as Texture2D); 430 | tmpColor *= 1-tmpTex.GetPixelBilinear(hit.textureCoord.x, hit.textureCoord.y).a; 431 | } 432 | else { 433 | tmpColor *= 1-tmpMat.color.a; 434 | } 435 | } 436 | //return resulting colour 437 | return tmpColor; 438 | } 439 | 440 | //Some stupid unnessesary and unused stuff to save the rendered texture to file 441 | //really not worth explaining 442 | function SaveTextureToFile(texture:Texture2D, fileName):void { 443 | var bytes = texture.EncodeToPNG(); 444 | var file = new File.Open(Application.dataPath + "/" + fileName,FileMode.Create); 445 | BinaryWriter(file).Write(bytes); 446 | file.Close(); 447 | } 448 | 449 | //Generates colliders used for raytracing for one GamObject 450 | //I wish I could add this to Instantiate!! 451 | function GenerateColliders(go:GameObject):GameObject { 452 | //Generate colliders only if there is a mesh filter 453 | if (go.GetComponent(MeshFilter)) { 454 | GenerateColliders(go.GetComponent(MeshFilter)); 455 | } 456 | //return same gameObject 457 | return go; 458 | } 459 | 460 | //Generate Colliders for a MeshFilter 461 | function GenerateColliders(mf:MeshFilter):GameObject { 462 | //Create Object 463 | tmpGameObject = GameObject("MeshRender"); 464 | //Set Defaults and copy settings 465 | tmpGameObject.transform.parent = mf.transform; 466 | tmpGameObject.AddComponent(MeshFilter).mesh = mf.mesh; 467 | tmpGameObject.AddComponent(MeshCollider).sharedMesh = mf.mesh; 468 | //Make collider a trigger 469 | tmpGameObject.collider.isTrigger = true; 470 | //reset positioning 471 | tmpGameObject.transform.localPosition = Vector3.zero; 472 | tmpGameObject.transform.localScale = Vector3.one; 473 | tmpGameObject.transform.rotation = mf.transform.rotation; 474 | //set layer 475 | tmpGameObject.layer = 31; 476 | //return MeshFilter 477 | return tmpGameObject; 478 | } 479 | -------------------------------------------------------------------------------- /Tutorial (Simple).md: -------------------------------------------------------------------------------- 1 | Building a RayTracer in Unity 2 | ============================= 3 | ##Intro 4 | Hello, and again, welcome to the "Building a RayTracer in Unity" tutorial. 5 | Here are a couple things you should probably know: 6 | 7 | - Everything will be statically typed... even function 8 | - I will post the full script after every chapter 9 | - This is made in Unity 4 indie. I have no guarantees it will work anywhere else 10 | - If at any time during this tutorial you get lost on something, please take the time to look it up, before you ask me 11 | - If you do not feel comfortable doing some basic programing, please learn before you come here :) 12 | 13 | Note that throughout this tutorial I am assuming that you are already aware of the basics behind raytracing.I also assume you have basic knowledge in programming in Unityscript. 14 | Note that I will not teach you scripting, nor will I answer any questions related to basic scripting problems, as there are enough tutorials out there that already do that. I am solely focusing on Raytracing in Unity. 15 | 16 | ##Part 1: Black and White 17 | The very first thing we should get working, is just getting unity to render something on the screen. For the time being, we are not going to worry what we are rendering, but more on how we are going to render it. 18 | 19 | Lets begin with the start of the script: Defining the variables. 20 | The Only variable we need as of yet is the texture we want to render too 21 | This textur emust be of type `Texture2D` as this is the only texture type which allows reading and writing. 22 | ```javascript 23 | private var renderTexture:Texture2D; 24 | ``` 25 | 26 | Now we must also create a new texture and assign it to our new variable 27 | We should do this in the `Awake` function, as this is the earliest point where we have access to the screen height 28 | ```javascript 29 | //Create render texture with screen size 30 | function Awake():void { 31 | renderTexture = new Texture2D(Screen.height, Screen.width); 32 | } 33 | ``` 34 | 35 | Now that we have the foundations, lets write the function that will do 1 full render 36 | We should split this "render" into 2 parts, as we will need the other part later 37 | Lets start with a function that loops through all the pixels 38 | 39 | ```javascript 40 | //The function that renders the entire scene to a texture 41 | function RayTrace():void { 42 | for (var x:int = 0; x < renderTexture.width; x += 1) { 43 | for (var y:int = 0; y < renderTexture.height; y += 1) { 44 | 45 | //Now that we have an x/y value for each pixel, we need to make that into a 3d ray 46 | //according to the camera we are attached to 47 | var ray:Ray = camera.ScreenPointToRay(Vector3(x, y, 0)); 48 | 49 | //Now lets call a function with this ray and apply it's return value to the pixel we are on 50 | //We will define this function afterwards 51 | renderTexture.SetPixel(x, y, TraceRay(ray)); 52 | } 53 | } 54 | 55 | //We also need to apply the changes we have made to the texture 56 | //This is a part that can cause much pain and frustraction if forgotten 57 | //So don't forget ;) 58 | renderTexture.Apply(); 59 | } 60 | ``` 61 | 62 | Next thing we have to do is get the rendering that's done for each pixel down. 63 | To do this I will be using the inbuilt `Raycast` function. 64 | I assume you already know how to use this function. 65 | For now all we want to do is find out if at the current pixel there is or isn't an object. 66 | In the first case, we will return white else black. It's that simple. 67 | 68 | ```javascript 69 | //Trace a Ray for a singple point 70 | function TraceRay(ray:Ray):Color { 71 | 72 | if (Physics.Raycast(ray)) { 73 | return Color.white; 74 | } 75 | 76 | return Color.black; 77 | } 78 | ``` 79 | 80 | Before we can test what we have written though, we need to actually display the texture on the screen. 81 | I preffer always doing this with `GUI` elements, specifically `DrawTexture` as it fits perfectly 82 | We also have to call our `RayTrace` function. Lets put it in `Start` for now 83 | 84 | ```javascript 85 | function Start():void { 86 | RayTrace(); 87 | } 88 | 89 | //Draw the render 90 | function OnGUI():void { 91 | GUI.DrawTexture(Rect(0, 0, Screen.width, Screen.height), renderTexture); 92 | } 93 | ``` 94 | 95 | Now we have a "working" raytracer. If we open up a new scene, place a couple of objects with colliders attached, attach our script to the camera and run it, we will see exactly what we had hoped for, Black and White: 96 | 97 | ![ScreenShot](http://db.tt/HbHYumol) 98 | 99 | Thats it for part 1, here is the code so far: 100 | ```javascript 101 | private var renderTexture:Texture2D; 102 | 103 | //Create render texture with screen size 104 | function Awake() { 105 | renderTexture = new Texture2D(Screen.width, Screen.height); 106 | } 107 | 108 | //Do one raytrace when we start playing 109 | function Start() { 110 | RayTrace(); 111 | } 112 | 113 | //Draw the render 114 | function OnGUI() { 115 | GUI.DrawTexture(Rect(0, 0, Screen.width, Screen.height), renderTexture); 116 | } 117 | 118 | //The function that renders the entire scene to a texture 119 | function RayTrace():void { 120 | for (var x:int = 0; x < renderTexture.width; x += 1) { 121 | for (var y:int = 0; y < renderTexture.height; y += 1) { 122 | 123 | //Now that we have an x/y value for each pixel, we need to make that into a 3d ray 124 | //according to the camera we are attached to 125 | var ray:Ray = camera.ScreenPointToRay(Vector3(x, y, 0)); 126 | 127 | //Now lets call a function with this ray and apply it's return value to the pixel we are on 128 | //We will define this function afterwards 129 | renderTexture.SetPixel(x, y, TraceRay(ray)); 130 | } 131 | } 132 | 133 | renderTexture.Apply(); 134 | } 135 | 136 | //Trace a Ray for a singple point 137 | function TraceRay(ray:Ray):Color { 138 | 139 | if (Physics.Raycast(ray)) { 140 | return Color.white; 141 | } 142 | 143 | return Color.black; 144 | } 145 | ``` 146 | 147 | ##Part 1.5: Additional Features 148 | As you might have noticed, it takes Unity some time to even render a simple scene with the code so far. It is certainly not a good idea to try and do this in real time, unless we change the resolution. 149 | I thought it might be a good Idea to add in some special features with this raytracer, more specifically the ability to render "real-time" and also the ability to "set" the resolution. 150 | Honestly features you should be able to add yourself, but I'll do it anyway. 151 | This will be a quite short part, but I will go over quickly adding these small features: 152 | 153 | 154 | First we need to add 2 more variables, ones accessible to the user: 155 | 156 | ```javascript 157 | //weather or not to render in real time 158 | var RealTime:boolean = false; 159 | 160 | //How much of our screen resolution we render at 161 | var RenderResolution:float = 1; 162 | ``` 163 | 164 | Lets first make the nessesary changes for adding real time: 165 | 166 | ```javascript 167 | //In Start we only render if we are not real time 168 | function Start() { 169 | if (!RealTime) { 170 | RayTrace(); 171 | } 172 | } 173 | 174 | //In the new Update, we only render if we are real time 175 | function Update() { 176 | if (RealTime) { 177 | RayTrace(); 178 | } 179 | } 180 | ``` 181 | 182 | Now lets change the `renderTexture` depending on the resolution we set, 183 | As well as cast the ray inversly relative to the resolution 184 | 185 | ```javascript 186 | //Create render texture with screen size with resolution 187 | function Awake() { 188 | renderTexture = new Texture2D(Screen.width*RenderResolution, Screen.height*RenderResolution); 189 | } 190 | 191 | //Now in our nested for loops 192 | var ray:Ray = camera.ScreenPointToRay(Vector3(x/RenderResolution, y/RenderResolution, 0)); 193 | ``` 194 | 195 | Now that we've added these simple features, lets move on to part 2 196 | And as always, heres all the code: 197 | 198 | ```javascript 199 | //weather or not to render in real time 200 | var RealTime:boolean = false; 201 | 202 | //How much of our screen resolution we render at 203 | var RenderResolution:float = 1; 204 | 205 | private var renderTexture:Texture2D; 206 | 207 | //Create render texture with screen size with resolution 208 | function Awake() { 209 | renderTexture = new Texture2D(Screen.width*RenderResolution, Screen.height*RenderResolution); 210 | } 211 | 212 | //Do one raytrace when we start playing 213 | function Start() { 214 | if (!RealTime) { 215 | RayTrace(); 216 | } 217 | } 218 | 219 | //Real Time Rendering 220 | function Update() { 221 | if (RealTime) { 222 | RayTrace(); 223 | } 224 | } 225 | 226 | //Draw the render 227 | function OnGUI() { 228 | GUI.DrawTexture(Rect(0, 0, Screen.width, Screen.height), renderTexture); 229 | } 230 | 231 | //The function that renders the entire scene to a texture 232 | function RayTrace():void { 233 | for (var x:int = 0; x < renderTexture.width; x += 1) { 234 | for (var y:int = 0; y < renderTexture.height; y += 1) { 235 | 236 | //Now that we have an x/y value for each pixel, we need to make that into a 3d ray 237 | //according to the camera we are attached to 238 | var ray:Ray = camera.ScreenPointToRay(Vector3(x/RenderResolution, y/RenderResolution, 0)); 239 | 240 | //Now lets call a function with this ray and apply it's return value to the pixel we are on 241 | //We will define this function afterwards 242 | renderTexture.SetPixel(x, y, TraceRay(ray)); 243 | } 244 | } 245 | 246 | renderTexture.Apply(); 247 | } 248 | 249 | //Trace a Ray for a singple point 250 | function TraceRay(ray:Ray):Color { 251 | 252 | if (Physics.Raycast(ray)) { 253 | return Color.white; 254 | } 255 | 256 | return Color.black; 257 | } 258 | ``` 259 | 260 | ##Part 2: Colors and Textures 261 | How about we now move away from just rendering black and white and let's use the color of the material of whatever we hit. 262 | The Main thing we are going to work on from now on, is going to be our `TraceRay` function, so assume from now on all code is written in there unless specifically stated otherwise: 263 | 264 | ```javascript 265 | //We fist have to create the hit variable 266 | var hit:RaycastHit; 267 | 268 | //Now we parse it in as another argument 269 | if (Physics.Raycast(ray, hit)) { 270 | //now we can get all kinds of information out of the "hit" 271 | //like hit.distance, hit.point, all of which will be usefull later on 272 | } 273 | 274 | return Color.black; 275 | ``` 276 | 277 | Next we should get the material we hit, then get it's color and return it: 278 | 279 | ```javascript 280 | var hit:RaycastHit; 281 | if (Physics.Raycast(ray, hit)) { 282 | 283 | //Create a temporary reference variable (useful later on) 284 | var mat:Material; 285 | 286 | //Get the material attached to the renderer of the collider we hit 287 | //if we used hit.transform instead, we would encounter bugs with rigidbodys 288 | //so we use collider 289 | mat = hit.collider.renderer.material; 290 | 291 | //return the main color of that material 292 | return mat.color; 293 | 294 | } 295 | return Color.black; 296 | ``` 297 | 298 | Congratulations, if we now make different materials for the objects and assign them different colours, our raytraced renderer will properly shade them. 299 | But just shading is quite boring. How about we add texturing while we're at it? 300 | One of the awesome things about Unity Raycasting, is that the raycast hit also returns a UV coordinate. 301 | This makes it very simple for us to also add texturing: 302 | 303 | ```javascript 304 | var hit:RaycastHit; 305 | 306 | if (Physics.Raycast(ray, hit)) { 307 | var mat:Material; 308 | mat = hit.collider.renderer.material; 309 | 310 | //if the material has a texture 311 | if (mat.mainTexture) { 312 | //return the color of the pixel at the pixel coordinate of the hit 313 | return (mat.mainTexture as Texture2D).GetPixelBilinear(hit.textureCoord.x, hit.textureCoord.y); 314 | } 315 | else { 316 | //return the material color 317 | return mat.color; 318 | } 319 | } 320 | return Color.black; 321 | ``` 322 | 323 | One note to make, is that this will only work if the texture of that material is read-write accessible. 324 | This can be set in the import options of that texture. 325 | Another note, is that to get the texture coordinates, you have to have a `MeshCollider` on the object. 326 | When looking at this, and thinking about the things we want to add later, it seems like it will be quite a pain (and a lot of `if` statements) for all possible values of the return color. 327 | Instead of doing what we are doing right now, lets make our lives easier and have 1 color we change throught that function? 328 | 329 | ```javascript 330 | //The color this function will return 331 | var returnColor:Color = Color.black; 332 | 333 | var hit:RaycastHit; 334 | 335 | if (Physics.Raycast(ray, hit)) { 336 | var mat:Material; 337 | mat = hit.collider.renderer.material; 338 | 339 | //Instead of returning or settings the color, we simply add the color 340 | if (mat.mainTexture) { 341 | returnColor += (mat.mainTexture as Texture2D).GetPixelBilinear(hit.textureCoord.x, hit.textureCoord.y); 342 | } 343 | else { 344 | returnColor += mat.color; 345 | } 346 | } 347 | 348 | //At the end, we simple return the color 349 | return returnColor 350 | ``` 351 | 352 | Yay! We now have textured and shaded objects. 353 | Lets see what it looks like so far? 354 | 355 | ![ScreenShot](http://db.tt/v63jXgat) 356 | 357 | Before we begin to add lighting, as promised, I will paste the full code again 358 | 359 | ```javascript 360 | //weather or not to render in real time 361 | var RealTime:boolean = false; 362 | 363 | //How much of our screen resolution we render at 364 | var RenderResolution:float = 1; 365 | 366 | private var renderTexture:Texture2D; 367 | 368 | //Create render texture with screen size with resolution 369 | function Awake() { 370 | renderTexture = new Texture2D(Screen.width*RenderResolution, Screen.height*RenderResolution); 371 | } 372 | 373 | //Do one raytrace when we start playing 374 | function Start() { 375 | if (!RealTime) { 376 | RayTrace(); 377 | } 378 | } 379 | 380 | //Real Time Rendering 381 | function Update() { 382 | if (RealTime) { 383 | RayTrace(); 384 | } 385 | } 386 | 387 | //Draw the render 388 | function OnGUI() { 389 | GUI.DrawTexture(Rect(0, 0, Screen.width, Screen.height), renderTexture); 390 | } 391 | 392 | //The function that renders the entire scene to a texture 393 | function RayTrace():void { 394 | for (var x:int = 0; x < renderTexture.width; x += 1) { 395 | for (var y:int = 0; y < renderTexture.height; y += 1) { 396 | 397 | //Now that we have an x/y value for each pixel, we need to make that into a 3d ray 398 | //according to the camera we are attached to 399 | var ray:Ray = camera.ScreenPointToRay(Vector3(x/RenderResolution, y/RenderResolution, 0)); 400 | 401 | //Now lets call a function with this ray and apply it's return value to the pixel we are on 402 | //We will define this function afterwards 403 | renderTexture.SetPixel(x, y, TraceRay(ray)); 404 | } 405 | } 406 | 407 | renderTexture.Apply(); 408 | } 409 | 410 | //Trace a Ray for a singple point 411 | function TraceRay(ray:Ray):Color { 412 | //The color we change throught the function 413 | var returnColor:Color = Color.black; 414 | 415 | var hit:RaycastHit; 416 | 417 | if (Physics.Raycast(ray, hit)) { 418 | 419 | //The material of the object we hit 420 | var mat:Material; 421 | 422 | //Set the used material 423 | mat = hit.collider.renderer.material; 424 | 425 | //if the material has a texture 426 | if (mat.mainTexture) { 427 | //return the color of the pixel at the pixel coordinate of the hit 428 | returnColor += (mat.mainTexture as Texture2D).GetPixelBilinear(hit.textureCoord.x, hit.textureCoord.y); 429 | } 430 | else { 431 | //return the material color 432 | returnColor += mat.color; 433 | } 434 | } 435 | 436 | //The color of this pixel 437 | return returnColor; 438 | } 439 | ``` 440 | 441 | ##Part 3: Finally some Light 442 | 443 | A very important part in any Raytraced renderer is always the way it handles light. 444 | In this part I will go over the basics of implementing directional lighting in our renderer. 445 | 446 | To do this, we need a function that asseses the light color, given a certain point. 447 | The first major information we need for this, are all the lights in the scene. 448 | For optimisation purposes, we will only do a full search for all lights before we render: 449 | 450 | ```javascript 451 | //We create a new variable to hold all lights 452 | private var lights:Light[]; 453 | 454 | //In our RayTrace Function 455 | //We find all lights 456 | function RayTrace():void { 457 | lights = FindSceneObjectsOfType(typeof(Light)) as Light[]; 458 | } 459 | ``` 460 | 461 | Now that we have access to all the lights, we begin writing the function to assess the lighting at a certain point. 462 | Just for nicer looking code, we should break this up into 2 functions. 463 | 464 | ```javascript 465 | //Trace a single point for all lights 466 | function TraceLight(pos:Vector3):Color { 467 | //We set the starting light to that of the render settings ambient light 468 | //This makes it easier to predict how it will look when we render it 469 | var returnColor:Color = RenderSettings.ambientLight; 470 | 471 | //We loop through all the lights and perform a light addition with each 472 | for (var light:Light in lights) { 473 | if (light.enabled) { 474 | //Add the light that this light source casts to the color of this point 475 | returnColor += LightTrace(light, pos); 476 | } 477 | } 478 | 479 | //return the color of this point according to lighting 480 | return returnColor; 481 | } 482 | 483 | //Trace a single point for a single light 484 | function LightTrace(light:Light, pos:Vector3):Color { 485 | //Only trace if it's a directional light 486 | if (light.type == LightType.Directional) { 487 | 488 | /* 489 | This needs some explaining: 490 | All we do here, is cast a ray indefinately in the opposite direction 491 | Of the way the directional light is facing. If this ray hits an object, it means 492 | that no light is recieved from this light source at this point, 493 | so we return black. 494 | If this ray doesn not hit, it means this point is recieving light from this light source 495 | so we return the color of the light, multiplied by it's intensity 496 | */ 497 | if (Physics.Raycast(pos, -light.transform.forward)) { 498 | return Color.black; 499 | } 500 | return light.color*light.intensity; 501 | } 502 | } 503 | ``` 504 | 505 | Before we can test this, we also need to add the `TraceLight` function into our `TraceRay` calculation, so that we take into account lighting for every point we hit. 506 | This is a relatively easy part, all we have to do is multiply the `returnColor` by the "light" at that point: 507 | 508 | ```javascript 509 | //After we apply the material color 510 | //We apply lighting 511 | returnColor *= TraceLight(hit.point); 512 | ``` 513 | 514 | And thats it! We now have shadows. 515 | 516 | ![ScreenShot](http://db.tt/Uz95LMVd) 517 | 518 | As you probably have noticed while playing around with the directional lighting we now have, 519 | That there is one major problem with this: White error spots... 520 | 521 | The problem is that we are tracing the light from the exact point on the surface. 522 | Due to inaccuracies of raycasting (due to floating point precision) there is no guarantee that the ray will intersect with the surface if it originates from it. 523 | The only way to counter this problem, is to trace our light from a point very slightly off the surface, using the normal: 524 | 525 | ```javascript 526 | //Instead of just tracing from the point 527 | //we add a small value of the hit normal to it 528 | returnColor *= TraceLight(hit.point + hit.normal*0.0001); 529 | ``` 530 | 531 | This tiny little change will make all the difference. 532 | 533 | ![ScreenShot](http://db.tt/4d86Kqfq) 534 | 535 | And here is all the code so far: 536 | 537 | ```javascript 538 | //weather or not to render in real time 539 | var RealTime:boolean = false; 540 | 541 | //How much of our screen resolution we render at 542 | var RenderResolution:float = 1; 543 | 544 | private var renderTexture:Texture2D; 545 | private var lights:Light[]; 546 | 547 | //Create render texture with screen size with resolution 548 | function Awake() { 549 | renderTexture = new Texture2D(Screen.width*RenderResolution, Screen.height*RenderResolution); 550 | } 551 | 552 | //Do one raytrace when we start playing 553 | function Start() { 554 | if (!RealTime) { 555 | RayTrace(); 556 | } 557 | } 558 | 559 | //Real Time Rendering 560 | function Update() { 561 | if (RealTime) { 562 | RayTrace(); 563 | } 564 | } 565 | 566 | //Draw the render 567 | function OnGUI() { 568 | GUI.DrawTexture(Rect(0, 0, Screen.width, Screen.height), renderTexture); 569 | } 570 | 571 | //The function that renders the entire scene to a texture 572 | function RayTrace():void { 573 | //Gather all lights 574 | lights = FindSceneObjectsOfType(typeof(Light)) as Light[]; 575 | 576 | for (var x:int = 0; x < renderTexture.width; x += 1) { 577 | for (var y:int = 0; y < renderTexture.height; y += 1) { 578 | 579 | //Now that we have an x/y value for each pixel, we need to make that into a 3d ray 580 | //according to the camera we are attached to 581 | var ray:Ray = camera.ScreenPointToRay(Vector3(x/RenderResolution, y/RenderResolution, 0)); 582 | 583 | //Now lets call a function with this ray and apply it's return value to the pixel we are on 584 | //We will define this function afterwards 585 | renderTexture.SetPixel(x, y, TraceRay(ray)); 586 | } 587 | } 588 | 589 | renderTexture.Apply(); 590 | } 591 | 592 | //Trace a Ray for a singple point 593 | function TraceRay(ray:Ray):Color { 594 | //The color we change throught the function 595 | var returnColor:Color = Color.black; 596 | 597 | var hit:RaycastHit; 598 | 599 | if (Physics.Raycast(ray, hit)) { 600 | 601 | //The material of the object we hit 602 | var mat:Material; 603 | 604 | //Set the used material 605 | mat = hit.collider.renderer.material; 606 | 607 | //if the material has a texture 608 | if (mat.mainTexture) { 609 | //return the color of the pixel at the pixel coordinate of the hit 610 | returnColor += (mat.mainTexture as Texture2D).GetPixelBilinear(hit.textureCoord.x, hit.textureCoord.y); 611 | } 612 | else { 613 | //return the material color 614 | returnColor += mat.color; 615 | } 616 | 617 | returnColor *= TraceLight(hit.point + hit.normal*0.0001); 618 | } 619 | 620 | //The color of this pixel 621 | return returnColor; 622 | } 623 | 624 | //Trace a single point for all lights 625 | function TraceLight(pos:Vector3):Color { 626 | //Set starting light to that of the render settings 627 | var returnColor:Color = RenderSettings.ambientLight; 628 | 629 | //We loop through all the lights and perform a light addition with each 630 | for (var light:Light in lights) { 631 | if (light.enabled) { 632 | //Add the light that this light source casts to the color of this point 633 | returnColor += LightTrace(light, pos); 634 | } 635 | } 636 | return returnColor; 637 | } 638 | 639 | //Trace a single point for a single light 640 | function LightTrace(light:Light, pos:Vector3):Color { 641 | //Trace the directional light 642 | if (light.type == LightType.Directional) { 643 | if (Physics.Raycast(pos, -light.transform.forward)) { 644 | return Color.black; 645 | } 646 | return light.color*light.intensity; 647 | } 648 | } 649 | ``` 650 | 651 | ##Part 4: Automatic Collision Setup 652 | 653 | So far we have always relied on whoever set up the scene to have put mesh colliders on everything. 654 | We have also been relying on there not being any functionality besides our renderer. 655 | The problem is in some cases, we just want to throw some things in the scene, run it and have it work. 656 | 657 | This part has nothing to do with raytracing, but it will make your life easier later on. 658 | Feel free to just skip to the end and copy the code. 659 | 660 | What we need to do is add our own colliders to all the objects in the scene. 661 | Put these colliders on a different layer (so they don't effect anything). 662 | And then only raycast this layer. 663 | 664 | Lets start by writing the function that does this automatically: 665 | 666 | ```javascript 667 | function GenerateColliders():void { 668 | 669 | //Loop through all mesh filters 670 | for (var mf:MeshFilter in FindSceneObjectsOfType(typeof MeshFilter) as MeshFilter[]) { 671 | 672 | //Only if they have a MeshRenderer attached 673 | //They might not... who knows? 674 | if (mf.GetComponent(MeshRenderer)) { 675 | //Create a new object we will use for rendering 676 | var tmpGO:GameObject = GameObject("RTRMeshRenderer"); 677 | 678 | //Add the Collider with the same mesh as the MeshFilter 679 | tmpGO.AddComponent(MeshCollider).sharedMesh = mf.mesh; 680 | 681 | //Make it a child of the MeshFilter 682 | tmpGO.transform.parent = mf.transform; 683 | 684 | //Make this new object the same dimentions as the meshFilter 685 | tmpGO.transform.localPosition = Vector3.zero; 686 | tmpGO.transform.localScale = Vector3.one; 687 | tmpGO.transform.localRotation = Quaternion.identity; 688 | 689 | //Make it a trigger (to avoid Physx) 690 | tmpGO.collider.isTrigger = true; 691 | 692 | //Set it's layer 693 | tmpGO.layer = 31; 694 | } 695 | } 696 | } 697 | ``` 698 | 699 | We then have to make the changes so that we only raycast that layer, and we also generate the coliders when we `Start`. 700 | 701 | ```javascript 702 | //Collision Mask 703 | private var collisionMask:LayerMask = 1 << 31; 704 | 705 | function Start() { 706 | //Generate Colliders for all objects 707 | GenerateColliders(); 708 | 709 | if (!RealTime) { 710 | RayTrace(); 711 | } 712 | } 713 | 714 | //In the TraceRay Function 715 | if (Physics.Raycast(ray, hit, collisionMask)) { 716 | //Also we need to access the parent of the object to be able to get rendering information 717 | mat = hit.collider.transform.parent.renderer.material; 718 | 719 | //In the LightTrace function 720 | if (Physics.Raycast(pos, -light.transform.forward, collisionMask)) { 721 | ``` 722 | 723 | And there we have it! Automatic collider setup. Now we can even run physics with no problems! 724 | 725 | As always, here is the complete code: 726 | 727 | ```javascript 728 | //weather or not to render in real time 729 | var RealTime:boolean = false; 730 | 731 | //How much of our screen resolution we render at 732 | var RenderResolution:float = 1; 733 | 734 | private var renderTexture:Texture2D; 735 | private var lights:Light[]; 736 | 737 | //Collision Mask 738 | private var collisionMask:LayerMask = 1 << 31; 739 | 740 | //Create render texture with screen size with resolution 741 | function Awake() { 742 | renderTexture = new Texture2D(Screen.width*RenderResolution, Screen.height*RenderResolution); 743 | } 744 | 745 | //Do one raytrace when we start playing 746 | function Start() { 747 | GenerateColliders(); 748 | 749 | if (!RealTime) { 750 | RayTrace(); 751 | } 752 | } 753 | 754 | //Real Time Rendering 755 | function Update() { 756 | if (RealTime) { 757 | RayTrace(); 758 | } 759 | } 760 | 761 | //Draw the render 762 | function OnGUI() { 763 | GUI.DrawTexture(Rect(0, 0, Screen.width, Screen.height), renderTexture); 764 | } 765 | 766 | //The function that renders the entire scene to a texture 767 | function RayTrace():void { 768 | //Gather all lights 769 | lights = FindSceneObjectsOfType(typeof(Light)) as Light[]; 770 | 771 | for (var x:int = 0; x < renderTexture.width; x += 1) { 772 | for (var y:int = 0; y < renderTexture.height; y += 1) { 773 | 774 | //Now that we have an x/y value for each pixel, we need to make that into a 3d ray 775 | //according to the camera we are attached to 776 | var ray:Ray = camera.ScreenPointToRay(Vector3(x/RenderResolution, y/RenderResolution, 0)); 777 | 778 | //Now lets call a function with this ray and apply it's return value to the pixel we are on 779 | //We will define this function afterwards 780 | renderTexture.SetPixel(x, y, TraceRay(ray)); 781 | } 782 | } 783 | 784 | renderTexture.Apply(); 785 | } 786 | 787 | //Trace a Ray for a singple point 788 | function TraceRay(ray:Ray):Color { 789 | //The color we change throught the function 790 | var returnColor:Color = Color.black; 791 | 792 | var hit:RaycastHit; 793 | 794 | if (Physics.Raycast(ray, hit, Mathf.Infinity, collisionMask)) { 795 | 796 | //The material of the object we hit 797 | var mat:Material; 798 | 799 | //Set the used material 800 | mat = hit.collider.transform.parent.renderer.material; 801 | 802 | //if the material has a texture 803 | if (mat.mainTexture) { 804 | //return the color of the pixel at the pixel coordinate of the hit 805 | returnColor += (mat.mainTexture as Texture2D).GetPixelBilinear(hit.textureCoord.x, hit.textureCoord.y); 806 | } 807 | else { 808 | //return the material color 809 | returnColor += mat.color; 810 | } 811 | 812 | returnColor *= TraceLight(hit.point + hit.normal*0.0001); 813 | } 814 | 815 | //The color of this pixel 816 | return returnColor; 817 | } 818 | 819 | //Trace a single point for all lights 820 | function TraceLight(pos:Vector3):Color { 821 | //Set starting light to that of the render settings 822 | var returnColor:Color = RenderSettings.ambientLight; 823 | 824 | //We loop through all the lights and perform a light addition with each 825 | for (var light:Light in lights) { 826 | if (light.enabled) { 827 | //Add the light that this light source casts to the color of this point 828 | returnColor += LightTrace(light, pos); 829 | } 830 | } 831 | return returnColor; 832 | } 833 | 834 | //Trace a single point for a single light 835 | function LightTrace(light:Light, pos:Vector3):Color { 836 | //Trace the directional light 837 | if (light.type == LightType.Directional) { 838 | if (Physics.Raycast(pos, -light.transform.forward, Mathf.Infinity, collisionMask)) { 839 | return Color.black; 840 | } 841 | return light.color*light.intensity; 842 | } 843 | } 844 | 845 | //Generate colliders for all objects 846 | function GenerateColliders():void { 847 | //Loop through all mesh filters 848 | for (var mf:MeshFilter in FindSceneObjectsOfType(typeof MeshFilter) as MeshFilter[]) { 849 | if (mf.GetComponent(MeshRenderer)) { 850 | //Create a new object we will use for rendering 851 | //And make it the same as the MeshFilter 852 | var tmpGO:GameObject = GameObject("RTRMeshRenderer"); 853 | tmpGO.AddComponent(MeshCollider).sharedMesh = mf.mesh; 854 | tmpGO.transform.parent = mf.transform; 855 | tmpGO.transform.localPosition = Vector3.zero; 856 | tmpGO.transform.localScale = Vector3.one; 857 | tmpGO.transform.localRotation = Quaternion.identity; 858 | 859 | tmpGO.collider.isTrigger = true; 860 | tmpGO.layer = 31; 861 | } 862 | } 863 | } 864 | ``` 865 | 866 | ##Pasrt 5: Shading with normals 867 | 868 | As you might have noticed, when we render something like a sphere, 869 | we have some obvious differences between how Unity renders it, and how we render it. 870 | The main difference is, that Unity determines the light at a point depending on the Normal of that surface. 871 | 872 | The way we can determine a multiplyer of our light color at that point, is by looking at a "dot product" 873 | 874 | A "Dot Product" is a mathamatical function, that allows us to determin the relationship between 2 directional vectors. 875 | Lets say we have 2 vectors that are equal. The dot product would equal 1. If they are perpendicular, it's 0. And if they are opposite, the dot product is -1. 876 | As you have probably noticed, this is exactly what we need, but it is also an optimisation, as we do not need to calculate lighting, if the dot product is negative. 877 | The way a dot product is calculated in Unity, is by using the inbuilt `Vector3` function: `Dot`. 878 | 879 | The first thing we need to do is parse both our lighting functions, the normal of the raycast hit: 880 | 881 | ```javascript 882 | //In TraceRay 883 | returnColor *= TraceLight(hit.point + hit.normal*0.0001, hit.normal); 884 | 885 | function TraceLight(pos:Vector3, normal:Vector3):Color { 886 | //When we call the other function: 887 | returnColor += LightTrace(light, pos, normal); 888 | 889 | function LightTrace(light:Light, pos:Vector3, normal:Vector3):Color { 890 | ``` 891 | 892 | In our `LightTrace` function, we can then calculate the dot and act accordingly: 893 | 894 | ```javascript 895 | //Trace the directional light 896 | if (light.type == LightType.Directional) { 897 | //calculate the dot product 898 | var dot:float = Vector3.Dot(-light.transform.forward, normal); 899 | 900 | //only perform lighting calculations, if the dot is more than 0 901 | if (dot > 0) { 902 | if (Physics.Raycast(pos, -light.transform.forward, Mathf.Infinity, collisionMask)) { 903 | return Color.black; 904 | } 905 | 906 | //return the color multiplied by the dot 907 | return light.color*light.intensity*dot; 908 | } 909 | //the face is facing away from the light, so no light is on it 910 | return Color.black; 911 | } 912 | ``` 913 | 914 | After running this you might think: Hey... it's an improvement... but now everything looks kind of blocky. 915 | AKA there is no smoothness in along the edges of the triangles that make a sphere. 916 | 917 | What you are reffering to is called Normal Interpolation. It's a very complex, computationally expensive calculation, that interpolates between the normals in a triangle to produce smooth looking surfaces. 918 | Most likely I will not be going over that in this tutorial, because of it's complexity. If you want an implementation of it, fell free to look at the github repository of my own Raytracer I built before making this tutorial. 919 | 920 | Now we have proper (fast) normal shading, isn't it awesome!? 921 | 922 | ![ScreenShot](http://db.tt/UmDHFr05) 923 | 924 | And now the code.... again... 925 | 926 | ```javascript 927 | //weather or not to render in real time 928 | var RealTime:boolean = false; 929 | 930 | //How much of our screen resolution we render at 931 | var RenderResolution:float = 1; 932 | 933 | private var renderTexture:Texture2D; 934 | private var lights:Light[]; 935 | 936 | //Collision Mask 937 | private var collisionMask:LayerMask = 1 << 31; 938 | 939 | //Create render texture with screen size with resolution 940 | function Awake() { 941 | renderTexture = new Texture2D(Screen.width*RenderResolution, Screen.height*RenderResolution); 942 | } 943 | 944 | //Do one raytrace when we start playing 945 | function Start() { 946 | GenerateColliders(); 947 | 948 | if (!RealTime) { 949 | RayTrace(); 950 | } 951 | } 952 | 953 | //Real Time Rendering 954 | function Update() { 955 | if (RealTime) { 956 | RayTrace(); 957 | } 958 | } 959 | 960 | //Draw the render 961 | function OnGUI() { 962 | GUI.DrawTexture(Rect(0, 0, Screen.width, Screen.height), renderTexture); 963 | } 964 | 965 | //The function that renders the entire scene to a texture 966 | function RayTrace():void { 967 | //Gather all lights 968 | lights = FindSceneObjectsOfType(typeof(Light)) as Light[]; 969 | 970 | for (var x:int = 0; x < renderTexture.width; x += 1) { 971 | for (var y:int = 0; y < renderTexture.height; y += 1) { 972 | 973 | //Now that we have an x/y value for each pixel, we need to make that into a 3d ray 974 | //according to the camera we are attached to 975 | var ray:Ray = camera.ScreenPointToRay(Vector3(x/RenderResolution, y/RenderResolution, 0)); 976 | 977 | //Now lets call a function with this ray and apply it's return value to the pixel we are on 978 | //We will define this function afterwards 979 | renderTexture.SetPixel(x, y, TraceRay(ray)); 980 | } 981 | } 982 | 983 | renderTexture.Apply(); 984 | } 985 | 986 | //Trace a Ray for a singple point 987 | function TraceRay(ray:Ray):Color { 988 | //The color we change throught the function 989 | var returnColor:Color = Color.black; 990 | 991 | var hit:RaycastHit; 992 | 993 | if (Physics.Raycast(ray, hit, Mathf.Infinity, collisionMask)) { 994 | 995 | //The material of the object we hit 996 | var mat:Material; 997 | 998 | //Set the used material 999 | mat = hit.collider.transform.parent.renderer.material; 1000 | 1001 | //if the material has a texture 1002 | if (mat.mainTexture) { 1003 | //return the color of the pixel at the pixel coordinate of the hit 1004 | returnColor += (mat.mainTexture as Texture2D).GetPixelBilinear(hit.textureCoord.x, hit.textureCoord.y); 1005 | } 1006 | else { 1007 | //return the material color 1008 | returnColor += mat.color; 1009 | } 1010 | 1011 | returnColor *= TraceLight(hit.point + hit.normal*0.0001, hit.normal); 1012 | } 1013 | 1014 | //The color of this pixel 1015 | return returnColor; 1016 | } 1017 | 1018 | //Trace a single point for all lights 1019 | function TraceLight(pos:Vector3, normal:Vector3):Color { 1020 | //Set starting light to that of the render settings 1021 | var returnColor:Color = RenderSettings.ambientLight; 1022 | 1023 | //We loop through all the lights and perform a light addition with each 1024 | for (var light:Light in lights) { 1025 | if (light.enabled) { 1026 | //Add the light that this light source casts to the color of this point 1027 | returnColor += LightTrace(light, pos, normal); 1028 | } 1029 | } 1030 | return returnColor; 1031 | } 1032 | 1033 | //Trace a single point for a single light 1034 | function LightTrace(light:Light, pos:Vector3, normal:Vector3):Color { 1035 | //Trace the directional light 1036 | if (light.type == LightType.Directional) { 1037 | //calculate the dot product 1038 | var dot:float = Vector3.Dot(-light.transform.forward, normal); 1039 | 1040 | //only perform lighting calculations, if the dot is more than 0 1041 | if (dot > 0) { 1042 | if (Physics.Raycast(pos, -light.transform.forward, Mathf.Infinity, collisionMask)) { 1043 | return Color.black; 1044 | } 1045 | 1046 | return light.color*light.intensity*dot; 1047 | } 1048 | return Color.black; 1049 | } 1050 | } 1051 | 1052 | //Generate colliders for all objects 1053 | function GenerateColliders():void { 1054 | //Loop through all mesh filters 1055 | for (var mf:MeshFilter in FindSceneObjectsOfType(typeof MeshFilter) as MeshFilter[]) { 1056 | if (mf.GetComponent(MeshRenderer)) { 1057 | //Create a new object we will use for rendering 1058 | //And make it the same as the MeshFilter 1059 | var tmpGO:GameObject = GameObject("RTRMeshRenderer"); 1060 | tmpGO.AddComponent(MeshCollider).sharedMesh = mf.mesh; 1061 | tmpGO.transform.parent = mf.transform; 1062 | tmpGO.transform.localPosition = Vector3.zero; 1063 | tmpGO.transform.localScale = Vector3.one; 1064 | tmpGO.transform.localRotation = Quaternion.identity; 1065 | 1066 | tmpGO.collider.isTrigger = true; 1067 | tmpGO.layer = 31; 1068 | } 1069 | } 1070 | } 1071 | ``` 1072 | 1073 | ##Part 6: More Lighting 1074 | 1075 | So now we have a raytracer that can do many things, but there are some key aspects that we have missed. 1076 | More specifically the different types of lights Unity offers. 1077 | 1078 | In this part, I will be going over how to add Point and Spot light support into the Raytracer. 1079 | Note that in this part all code will be in the `LigthTrace` function. 1080 | 1081 | Lets start with Point as it's easier. 1082 | ###Point Lights 1083 | First we have to consider all the aspects of a point light: 1084 | 1085 | - Range 1086 | - Intensity 1087 | - Color 1088 | 1089 | Intensity and Color we have already implemented sucessfully in our Directional lighting, but Range adds a whole new consept. 1090 | No longer will we have either a light at full brightness or in the shadow, but interpolation between fully bright and in the shadows. 1091 | We also have to consider that our Raycast can not be infinite, because the light source has an origin, unlike a directional light. 1092 | 1093 | Lets start by calculating the distance from our point to the light. 1094 | Because both point and spot are so similar, I will make some optimisations for each. 1095 | 1096 | ```javascript 1097 | function LightTrace(light:Light, pos:Vector3, normal:Vector3):Color { 1098 | if (light.type == LightType.Directional) { 1099 | } 1100 | else { 1101 | //calculate the distance between our point and the light 1102 | var distance:float = Vector3.Distance(pos, light.transform.position); 1103 | 1104 | //No matter if the light is point or spot, it still has a range and we account for that 1105 | if (distance < light.range) { 1106 | 1107 | //Now we have to check for which type of light it is 1108 | if (light.type == LightType.Point) { 1109 | } 1110 | } 1111 | 1112 | //we are outside of the lights range, so no need for light 1113 | return Color.black; 1114 | } 1115 | } 1116 | ``` 1117 | 1118 | While we are at it, lets also account for the new normal shading, which is again the same for both light types. 1119 | As an optimisation I will create 2 new variables as we will need both later. 1120 | 1121 | ```javascript 1122 | function LightTrace(light:Light, pos:Vector3, normal:Vector3):Color { 1123 | //Because we have already defined dot in here, we should define it at the top of our funstion and only use it inside 1124 | //If you do not do this, you will recieve errors 1125 | var dot:float; 1126 | 1127 | if (light.type == LightType.Directional) { 1128 | //We also need to change this line, to remove errors it would generate 1129 | dot = Vector3.Dot(-light.transform.forward, normal); 1130 | } 1131 | else { 1132 | //Lets calculate the direction from our point, to the light. 1133 | //we will need this for both the normal shading and also shadow checking 1134 | var direction:Vector3 = (light.transform.position - pos).normalized; 1135 | 1136 | //Now we calculate the dot product of the direction and the normal. 1137 | dot = Vector3.Dot(normal, direction); 1138 | 1139 | var distance:float = Vector3.Distance(pos, light.transform.position); 1140 | 1141 | //We also check if our dot is larger than 0 here 1142 | if (distance < light.range && dot > 0) { 1143 | if (light.type == LightType.Point) { 1144 | } 1145 | } 1146 | return Color.black; 1147 | } 1148 | } 1149 | ``` 1150 | 1151 | Now we move on to the logic behind what color to return: 1152 | It's acctually quite simple. 1153 | If a raycast from our point, in the direction we calculated, with the maximum distance we calculated hit's anything, we return black as usual. 1154 | Else we return the color of the light multiplied by it's intensity and by the dot (as per usual), but then we also multiply it by the percentage of distance we are from the light source origin. 1155 | 1156 | If you don't understand it, I don't blame you... Heres the formula for our new multiplier: `1 - light.range/distance`. 1157 | 1158 | So all we have to do is: 1159 | 1160 | ```javascript 1161 | function LightTrace(light:Light, pos:Vector3, normal:Vector3):Color { 1162 | if (light.type == LightType.Directional) { 1163 | } 1164 | else { 1165 | var direction:Vector3 = (light.transform.position - pos).normalized; 1166 | dot = Vector3.Dot(normal, direction); 1167 | var distance:float = Vector3.Distance(pos, light.transform.position); 1168 | if (distance < light.range && dot > 0) { 1169 | if (light.type == LightType.Point) { 1170 | //Raycast as we described 1171 | if (Physics.Raycast(pos, direction, distance, collisionMask)) { 1172 | return Color.black; 1173 | } 1174 | 1175 | //Amd then our new formula 1176 | return light.color*light.intensity*dot*(1 - light.range/distance); 1177 | 1178 | } 1179 | } 1180 | return Color.black; 1181 | } 1182 | } 1183 | ``` 1184 | 1185 | And there we have it... we now have working point lights! 1186 | 1187 | ###Spot Lights 1188 | 1189 | Lets do this in the same fassion that we did with point lights. 1190 | Fist lets consider all aspects of a spot light: 1191 | 1192 | - Spot Angle 1193 | - Range 1194 | - Intensity 1195 | - Color 1196 | 1197 | Like before we have 1 new thing to work on. Although it might not be exactly the same way Unity does it, but let's consider a spot light to be a point light, where there is a limited angle of exposure. This means, that the dot product of the direction to the light source and the backward direction of the light must be smaller than the Spot angle transformed in some way. 1198 | If we consider that dot product would range from 1 to 0 with 180 degrees of the lights forward direction. 1199 | Therefore, the point is within the spot light, if the `dot > 1 - light.spotAngle/180`. 1200 | 1201 | But just finding weather or not the point is within the spot is not enough. We also have to interpolate between the edge of the spot angle and the dot. So as well as considering distance when we calculate the color, we have a new multiplier: `(dot/(1 - light.spotAngle/180))` 1202 | 1203 | Lets implement this. As we already have most of the information present, this should be easy: 1204 | 1205 | ```javascript 1206 | function LightTrace(light:Light, pos:Vector3, normal:Vector3):Color { 1207 | if (light.type == LightType.Directional) { 1208 | } 1209 | else { 1210 | if (distance < light.range && dot > 0) { 1211 | if (light.type == LightType.Point) { 1212 | } 1213 | //Lets check weather we are in the spot or not 1214 | else if (light.type == LightType.Spot) { 1215 | //Get the dot product between the backwards direction of the light and our direction to it 1216 | var dot2:float = Vector3.Dot(-light.transform.forward, normal); 1217 | 1218 | //Only do spot lighting if we are within the spot light 1219 | if (dot2 < (1 - light.spotAngle/180)) { 1220 | if (Physics.Raycast(pos, direction, distance, collisionMask)) { 1221 | return Color.black; 1222 | } 1223 | 1224 | //We multiply by the multiplier we defined above 1225 | return light.color*light.intensity*dot*(1 - light.range/distance)*((dot2/(1 - light.spotAngle/180))); 1226 | } 1227 | } 1228 | } 1229 | return Color.black; 1230 | } 1231 | } 1232 | ``` 1233 | 1234 | And there we go! We now have working spot lights. They don't work in quite the same way as the ones in Unity, but at least they are spot lights. 1235 | 1236 | Lets look at both of them in action: 1237 | 1238 | ![ScreenShot](http://db.tt/uI4mSUXA) 1239 | 1240 | On that note, here is also the current code: 1241 | 1242 | ```javascript 1243 | //weather or not to render in real time 1244 | var RealTime:boolean = false; 1245 | 1246 | //How much of our screen resolution we render at 1247 | var RenderResolution:float = 1; 1248 | 1249 | private var renderTexture:Texture2D; 1250 | private var lights:Light[]; 1251 | 1252 | //Collision Mask 1253 | private var collisionMask:LayerMask = 1 << 31; 1254 | 1255 | //Create render texture with screen size with resolution 1256 | function Awake() { 1257 | renderTexture = new Texture2D(Screen.width*RenderResolution, Screen.height*RenderResolution); 1258 | } 1259 | 1260 | //Do one raytrace when we start playing 1261 | function Start() { 1262 | GenerateColliders(); 1263 | 1264 | if (!RealTime) { 1265 | RayTrace(); 1266 | RTRenderer.SaveTextureToFile(renderTexture, "lolies.png"); 1267 | } 1268 | } 1269 | 1270 | //Real Time Rendering 1271 | function Update() { 1272 | if (RealTime) { 1273 | RayTrace(); 1274 | } 1275 | } 1276 | 1277 | //Draw the render 1278 | function OnGUI() { 1279 | GUI.DrawTexture(Rect(0, 0, Screen.width, Screen.height), renderTexture); 1280 | } 1281 | 1282 | //The function that renders the entire scene to a texture 1283 | function RayTrace():void { 1284 | //Gather all lights 1285 | lights = FindSceneObjectsOfType(typeof(Light)) as Light[]; 1286 | 1287 | for (var x:int = 0; x < renderTexture.width; x += 1) { 1288 | for (var y:int = 0; y < renderTexture.height; y += 1) { 1289 | 1290 | //Now that we have an x/y value for each pixel, we need to make that into a 3d ray 1291 | //according to the camera we are attached to 1292 | var ray:Ray = camera.ScreenPointToRay(Vector3(x/RenderResolution, y/RenderResolution, 0)); 1293 | 1294 | //Now lets call a function with this ray and apply it's return value to the pixel we are on 1295 | //We will define this function afterwards 1296 | renderTexture.SetPixel(x, y, TraceRay(ray)); 1297 | } 1298 | } 1299 | 1300 | renderTexture.Apply(); 1301 | } 1302 | 1303 | //Trace a Ray for a singple point 1304 | function TraceRay(ray:Ray):Color { 1305 | //The color we change throught the function 1306 | var returnColor:Color = Color.black; 1307 | 1308 | var hit:RaycastHit; 1309 | 1310 | if (Physics.Raycast(ray, hit, Mathf.Infinity, collisionMask)) { 1311 | 1312 | //The material of the object we hit 1313 | var mat:Material; 1314 | 1315 | //Set the used material 1316 | mat = hit.collider.transform.parent.renderer.material; 1317 | 1318 | //if the material has a texture 1319 | if (mat.mainTexture) { 1320 | //return the color of the pixel at the pixel coordinate of the hit 1321 | returnColor += (mat.mainTexture as Texture2D).GetPixelBilinear(hit.textureCoord.x, hit.textureCoord.y); 1322 | } 1323 | else { 1324 | //return the material color 1325 | returnColor += mat.color; 1326 | } 1327 | 1328 | returnColor *= TraceLight(hit.point + hit.normal*0.0001, hit.normal); 1329 | } 1330 | 1331 | //The color of this pixel 1332 | return returnColor; 1333 | } 1334 | 1335 | //Trace a single point for all lights 1336 | function TraceLight(pos:Vector3, normal:Vector3):Color { 1337 | //Set starting light to that of the render settings 1338 | var returnColor:Color = RenderSettings.ambientLight; 1339 | 1340 | //We loop through all the lights and perform a light addition with each 1341 | for (var light:Light in lights) { 1342 | if (light.enabled) { 1343 | //Add the light that this light source casts to the color of this point 1344 | returnColor += LightTrace(light, pos, normal); 1345 | } 1346 | } 1347 | return returnColor; 1348 | } 1349 | 1350 | //Trace a single point for a single light 1351 | function LightTrace(light:Light, pos:Vector3, normal:Vector3):Color { 1352 | var dot:float; 1353 | 1354 | //Trace the directional light 1355 | if (light.type == LightType.Directional) { 1356 | //calculate the dot product 1357 | dot = Vector3.Dot(-light.transform.forward, normal); 1358 | 1359 | //only perform lighting calculations, if the dot is more than 0 1360 | if (dot > 0) { 1361 | if (Physics.Raycast(pos, -light.transform.forward, Mathf.Infinity, collisionMask)) { 1362 | return Color.black; 1363 | } 1364 | 1365 | return light.color*light.intensity*dot; 1366 | } 1367 | return Color.black; 1368 | } 1369 | else { 1370 | var direction:Vector3 = (light.transform.position - pos).normalized; 1371 | dot = Vector3.Dot(normal, direction); 1372 | var distance:float = Vector3.Distance(pos, light.transform.position); 1373 | if (distance < light.range && dot > 0) { 1374 | if (light.type == LightType.Point) { 1375 | //Raycast as we described 1376 | if (Physics.Raycast(pos, direction, distance, collisionMask)) { 1377 | return Color.black; 1378 | } 1379 | return light.color*light.intensity*dot*(1 - distance/light.range); 1380 | } 1381 | //Lets check weather we are in the spot or not 1382 | else if (light.type == LightType.Spot) { 1383 | var dot2:float = Vector3.Dot(-light.transform.forward, direction); 1384 | if (dot2 > (1 - light.spotAngle/180)) { 1385 | if (Physics.Raycast(pos, direction, distance, collisionMask)) { 1386 | return Color.black; 1387 | } 1388 | 1389 | //We multiply by the multiplier we defined above 1390 | return light.color*light.intensity*dot*(1 - distance/light.range)*((dot2/(1 - light.spotAngle/180))); 1391 | } 1392 | } 1393 | } 1394 | return Color.black; 1395 | } 1396 | } 1397 | 1398 | //Generate colliders for all objects 1399 | function GenerateColliders():void { 1400 | //Loop through all mesh filters 1401 | for (var mf:MeshFilter in FindSceneObjectsOfType(typeof MeshFilter) as MeshFilter[]) { 1402 | if (mf.GetComponent(MeshRenderer)) { 1403 | //Create a new object we will use for rendering 1404 | //And make it the same as the MeshFilter 1405 | var tmpGO:GameObject = GameObject("RTRMeshRenderer"); 1406 | tmpGO.AddComponent(MeshCollider).sharedMesh = mf.mesh; 1407 | tmpGO.transform.parent = mf.transform; 1408 | tmpGO.transform.localPosition = Vector3.zero; 1409 | tmpGO.transform.localScale = Vector3.one; 1410 | tmpGO.transform.localRotation = Quaternion.identity; 1411 | 1412 | tmpGO.collider.isTrigger = true; 1413 | tmpGO.layer = 31; 1414 | } 1415 | } 1416 | } 1417 | ``` 1418 | 1419 | ##Conclusion 1420 | 1421 | After quite a long time, I have finally finished this tutorial. I hope it was at least of some use to you. 1422 | Although I myself have written a way more advanced Raytraced Renderer than the one I wrote for this tutorial, It was definately fun. If you have any questions, feel free to hit me up on the Unity Forums. 1423 | 1424 | My name is Benproductions1 1425 | Have a nice day 1426 | 1427 | Unity Forums: 1428 | http://forum.unity3d.com/members/45364-Benproductions1 1429 | http://forum.unity3d.com/threads/178992-RayTracing-Tutorial-Full-(Simple) 1430 | 1431 | My RayTracer: 1432 | https://github.com/Benproductions1/Unity-Raytracer 1433 | --------------------------------------------------------------------------------