Render images, README.

README.md

@@ -7,6 +7,8 @@ Terry Sun; Arch Linux, Intel i5-4670, GTX 750
 
 A CUDA-accelerated path tracer: a global-illumination renderer.
 
+![](img/main-10000.png)
+
 ## Features
 
 ### Materials
@@ -17,8 +19,14 @@ The pathtracer supports the following material surfaces:
 * specular/reflective (perfect and imperfect): light reflects perfectly off the
   surface; or, light takes an imperfect reflected directly using the [Phong
   BRDF][gpu-specular].
-* refractive (using [Schlick's Approximation][wiki-schlick] to blend reflective
-  and refractive light bounces): glass, water
+* refractive (using [Schlick's Approximation][wiki-schlick] of the Fresnel
+  effect to blend reflective and refractive light bounces).
+
+![](img/specular-5000.png)
+![](img/refract-5000.png)
+
+*(Left: specular exponent 200; specular exponent 25)*
+*(Right: indices of refraction 1.31 (water ice), 1.7 (impure glass))*
 
   [gpu-specular]: http://http.developer.nvidia.com/GPUGems3/gpugems3_ch20.html
   [wiki-schlick]: https://en.wikipedia.org/wiki/Schlick%27s_approximation
@@ -30,30 +38,81 @@ of rays shot from the camera. DOF is defined with a focal distance from the
 camera, at which objects are perfectly in focus, and an aperture radius,
 defining the amount of variance added to each ray.
 
-![](img/nodof.png)
-![](img/dof05.png)
-![](img/dof03.png)
+![](img/dof-none-5000.png)
+![](img/dof04-5000.png)
+
+*(no DOF; DOF with distance 5.5, aperture 0.4; 5000 iterations each)*
 
 ### Antialiasing
 
 Camera rays are shot from the camera's position in the direction of a pixel.
-Antialiasing jitters the target of the ray within a pixel.
+Antialiasing jitters the target of the ray within a pixel. This is a brief
+computation that happens once per pixel per iteration; it has little impact on
+performance.
+
+![](img/aa-none-5000.png)
+![](img/aa-5000.png)
+
+*(note antialiasing along cube, light, and wall corners)*
+
+### Texture mapping
+
+Textures can be read in to define diffuse colors for a material.
+
+For spheres, polar coordinates *phi* and *theta* are used as the UV coordinates,
+wrapping a texture across a sphere. For cubes, polar coordinates are calculated
+relative to the cube face; each face of the cube has an identical copy of the
+texture.
+
+For both texture and normal mapping: add a small amount of complexity to the
+intersection tesitng code in order to output UV coordinates. Most of the cost,
+if any, would come from additional memory requirements (access into global
+memory when reading the texture).
 
-[TODO: picture]
+![](img/uv1-5000.png)
+![](img/uv2-5000.png)
+
+### Normal mapping
+
+Textures can be read in to define ray-bounce surface normals (superceding normal
+vectors generated by the geometry intersection).
+
+Combining the two above effects:
+
+![](img/globe-texture-5000.png)
+![](img/globe-normal-5000.png)
+![](img/globe-both-5000.png)
+
+*(normal map only; texture map only; texture and normal map)*
 
 ### Stream compaction.
 
-Shared-memory work-efficient stream compaction.
+This pathtracer uses `thrust::remove_if` to perform stream compaction on dead
+rays.
 
-[TODO: analysis]
+I also implemented a [GPU-shared-memory, work-efficient stream compaction
+algorithm][p2-shared-mem]. Unfortunately I couldn't integrate that into this
+project -- I suspect there are memory errors when I translated the stream
+compaction to handle pathtracing structs rather than integer values.
 
-### Texture mapping
+  [p2-shared-mem]: https://github.com/terrynsun/CIS565-P2-Stream-Compaction
+
+w. stream compaction
+500 iterations, w. back wall: 61.30s
+500 iterations, w/o. back wall: 61.76
 
-[TODO: picture(s)]
+w/o. stream compaction
+500 iterations, w. back wall: 47.95
+500 iterations, w/o. back wall: 47.84
 
-### Bump mapping
+With - without stream compaction
+Open box:
+Closed box:
 
-[TODO: picture(s)]
+Small light:
+Large light:
+
+[TODO: analysis]
 
 ## Run
 
@@ -104,7 +163,6 @@ MATERIAL  (material ID)                 //material header
 RGB       (float r) (float g) (float b) //diffuse color
 SPECX     (float specx)                 //specular exponent
 SPECRGB   (float r) (float g) (float b) //specular color
-REFR      (bool refr)       //refractivity flag, 0 for no, 1 for yes
 REFRIOR   (float ior)       //index of refraction for Fresnel effects
 EMITTANCE (float emittance) //the emittance of the material; >0 is a light source
 TEXTURE   (int textureid)   //texture corresponding to diffuse coloring

scenes/aa.txt

@@ -0,0 +1,100 @@
+// Camera
+CAMERA
+RES         100 100
+FOVY        45
+ITERATIONS  5000
+DEPTH       8
+FILE        aa
+DOF         -1 -1
+EYE         0 8 2.5
+VIEW        0 0 -1
+UP          0 1 0
+
+// ---------------------- Materials ---------------------- \\
+
+// Emissive material (light)
+MATERIAL 0
+RGB         1 1 1
+EMITTANCE   2
+
+// Diffuse white
+MATERIAL 1
+RGB         .98 .98 .98
+
+// Diffuse orange
+MATERIAL 2
+RGB         0.85 .5 .3
+
+// Diffuse purple
+MATERIAL 3
+RGB         0.55 .55 .85
+
+// Textured
+MATERIAL 4
+RGB         .35 .75 .35
+
+// ---------------------- Objects ---------------------- \\
+
+// Ceiling light
+OBJECT 0
+cube
+material 0
+TRANS       0 10 0
+ROTAT       0 0 0
+SCALE       6 .3 6
+
+// Floor
+OBJECT 1
+cube
+material 1
+TRANS       0 0 0
+ROTAT       0 0 0
+SCALE       10 0.1 10
+
+// Ceiling
+OBJECT 2
+cube
+material 1
+TRANS       0 10 0
+ROTAT       0 0 90
+SCALE       0.1 10 10
+
+// Back wall
+OBJECT 3
+cube
+material 1
+TRANS       0 5 -5
+ROTAT       0 90 0
+SCALE       0.1 10 10
+
+// Front wall
+OBJECT 4
+cube
+material 1
+TRANS       0 5 5
+ROTAT       0 90 0
+SCALE       0.1 10 10
+
+// Left wall
+OBJECT 5
+cube
+material 2
+TRANS       -5 5 0
+ROTAT       0 0 0
+SCALE       0.1 10 10
+
+// Right wall
+OBJECT 6
+cube
+material 3
+TRANS       5 5 0
+ROTAT       0 0 0
+SCALE       0.1 10 10
+
+// White textured
+OBJECT 7
+cube
+material 4
+TRANS       0 6 -1.5
+ROTAT       0 15 25
+SCALE       3 3 3

scenes/cornell.txt

@@ -1,10 +1,10 @@
 // Camera
 CAMERA
-RES         800 800
+RES         350 350
 FOVY        45
-ITERATIONS  500
+ITERATIONS  5000
 DEPTH       8
-FILE        cornell
+FILE        specular
 DOF         -1 -1
 EYE         0.0 5 4.5
 VIEW        0 0 -1
@@ -21,29 +21,35 @@ EMITTANCE   3
 MATERIAL 1
 RGB         .98 .98 .98
 
-// Diffuse red
+// Diffuse orange
 MATERIAL 2
-RGB         .85 .35 .35
+RGB         0.85 .5 .3
 
-// Diffuse green
+// Diffuse purple
 MATERIAL 3
-RGB         .35 .85 .35
+RGB         0.55 .55 .85
 
-// Specular yellow
+// Globe textured
 MATERIAL 4
-RGB         0.4 0.4 0
-SPECEX      50
-SPECRGB     1 1 1
+RGB         .85 .35 .35
 
-// Refractive green
+// Perfect specular
 MATERIAL 5
-RGB         0.0 0.8 0.8
-REFR        1
-REFRIOR     1.5
+RGB         .3 .3 .3
+SPECRGB     .8 .8 .8
+SPECEX      0
 
-// Diffuse orange
+// Imperfect specular
 MATERIAL 6
-RGB         .8 .8 0
+RGB         .3 .3 .3
+SPECRGB     .8 .8 .8
+SPECEX      20
+
+// Less imperfect specular
+MATERIAL 7
+RGB         .3 .3 .3
+SPECRGB     .8 .8 .8
+SPECEX      100
 
 // ---------------------- Objects ---------------------- \\
 
@@ -103,18 +109,34 @@ TRANS       5 5 0
 ROTAT       0 0 0
 SCALE       0.1 10 10
 
-// Specular Yellow
+// Reddish
 OBJECT 7
 sphere
 material 4
-TRANS       -2 6 -1
+TRANS       0 2.5 -2.5
 ROTAT       0 0 0
 SCALE       3 3 3
 
-// Glass sphere
+// Imperfect specular
 OBJECT 8
 sphere
 material 6
-TRANS       0 2 -1.5
+TRANS       -3 4.5 -0.5
+ROTAT       0 0 0
+SCALE       3 3 3
+
+// Imperfect specular
+OBJECT 9
+sphere
+material 7
+TRANS       3 4.5 -0.5
+ROTAT       0 0 0
+SCALE       3 3 3
+
+// Perfect specular
+OBJECT 10
+sphere
+material 5
+TRANS       0 5.5 -3.5
 ROTAT       0 0 0
 SCALE       3 3 3

scenes/dof.txt

@@ -5,7 +5,7 @@ FOVY        45
 ITERATIONS  5000
 DEPTH       8
 FILE        dof
-DOF         -1 -1
+DOF         5.5 0.4
 EYE         0.0 5 4.5
 VIEW        0 0 -1
 UP          0 1 0