CIS565-Fall-2018 · wuyan33 · Sep 29, 2018 · Sep 29, 2018 · Oct 1, 2018 · Oct 1, 2018
diff --git a/README.md b/README.md
@@ -3,11 +3,51 @@ CUDA Path Tracer
 
 **University of Pennsylvania, CIS 565: GPU Programming and Architecture, Project 3**
 
-* (TODO) YOUR NAME HERE
-* Tested on: (TODO) Windows 22, i7-2222 @ 2.22GHz 22GB, GTX 222 222MB (Moore 2222 Lab)
+* Yan Wu
+* [LinknedIn](https://www.linkedin.com/in/yan-wu-a71270159/)
+* Tested on: Windows 10, i7-8750H @ 2.20GHz 16GB, GTX 1060 6GB (Personal Laptop)
 
-### (TODO: Your README)
+### Project Description
+ In this project, I implemented a CUDA-based path tracer capable of rendering images. Since in this class we are concerned with working in GPU programming, performance, and the generation of actual beautiful images (and not with mundane programming tasks like I/O), this project includes base code for loading a scene description file, described below, and various other things that generally make up a framework for previewing and saving images.
 
-*DO NOT* leave the README to the last minute! It is a crucial part of the
-project, and we will not be able to grade you without a good README.
+### Features
+* Basic Features:
+   - A shading kernel with BSDF evaluation for:
+      - Ideal Diffuse surfaces (using provided cosine-weighted scatter function, see below.) [PBRT 8.3].
+      - Perfectly specular-reflective (mirrored) surfaces (e.g. using glm::reflect).
+      - See notes on diffuse/specular in scatterRay and on imperfect specular below.
+   - Path continuation/termination using Stream Compaction
+   - Implemented a means of making rays/pathSegments/intersections contiguous in memory by material type
+      - Sort the rays/path segments so that rays/paths interacting with the same material are contiguous in memory
+   - A toggleable option to cache the first bounce intersections for re-use across all subsequent iterations.
 
+* Extra Features:
+   - Refraction (e.g. glass/water) [PBRT 8.2] with Frensel effects using Schlick's approximation [PBRT 8.5]. 
+   - Physically-based depth-of-field (by jittering rays within an aperture) [PBRT 6.2.3].
+   - Antialiasing.
+   - More exciting features in the future...
+
+### Result and comparison
+* Original scene without anything: <br />
+   <img src="images/initial.gif" width = "50%"> <br />
+* Without implementing Stream Compaction(So slow!): <br />
+   <img src="images/withoutCompaction.gif" width = "50%"> <br />
+   We can see that even those useless paths are taken into count. By using stream compaction we can get a way more efficient outcome.
+
+* With fraction vs Without fraction:<br />
+   <img src="images/withoutRefract.png" width = "45%"> <img src="images/sorting slow.png" width = "45%"> <br />
+   More realistic with refraction implemented!
+* With Anti-Aliasing vs Non-Anti-Aliasing:<br />
+    <img src="images/no_antialiasing.png" width = "45%"> <img src="images/antialiasing1608samp.png" width = "45%"> <br />
+    <img src="images/aliasCompare.PNG" width = "80%"> <br />
+    If we check carefully at the baseline of the walls, especially on the back wall, we could see that the anti-aliasing feature is working.
+* With DOF(Depth of Field) vs No DOF:<br />
+    <img src="images/withoutDOF.png" width = "45%"> <img src="images/0.5DOF20.png" width = "45%"><br />
+    Depth of Field implemented great, we can totally see the difference as distance changes. The program with DOF only executed 433 loop so the right picture is a little too blurry.
+
+### Bloopers
+* Here are some interesting bugs I encountered when I was trying to implement schlick's approximation(left) and DOF(right).<br />
+    <img src="images/schlick wrong 2.png" width = "45%"> <img src="images/dof10samp364.png" width = "45%"><br />
+
+
+
diff --git a/images/0.5DOF20.png b/images/0.5DOF20.png
diff --git a/images/0.5dofsamp131.png b/images/0.5dofsamp131.png
diff --git a/images/aliasCompare.PNG b/images/aliasCompare.PNG
diff --git a/images/antialiasing1608samp.png b/images/antialiasing1608samp.png
diff --git a/images/antialiasing420samp.png b/images/antialiasing420samp.png
diff --git a/images/cache 3194sample.png b/images/cache 3194sample.png
diff --git a/images/cache.png b/images/cache.png
diff --git a/images/cornell.2018-10-02_23-37-45z.267samp.png b/images/cornell.2018-10-02_23-37-45z.267samp.png
diff --git a/images/dof10samp364.png b/images/dof10samp364.png
diff --git a/images/dof16samp358.png b/images/dof16samp358.png
diff --git a/images/dof20samp598.png b/images/dof20samp598.png
diff --git a/images/initial.gif b/images/initial.gif
diff --git a/images/no_antialiasing.png b/images/no_antialiasing.png
diff --git a/images/schlick working.png b/images/schlick working.png
diff --git a/images/schlick wrong 1.png b/images/schlick wrong 1.png
diff --git a/images/schlick wrong 2.png b/images/schlick wrong 2.png
diff --git a/images/sorting slow.png b/images/sorting slow.png
diff --git a/images/withoutCompaction.gif b/images/withoutCompaction.gif
diff --git a/images/withoutDOF.png b/images/withoutDOF.png
diff --git a/images/withoutRefract.png b/images/withoutRefract.png
diff --git a/scenes/cornell.txt b/scenes/cornell.txt
@@ -1,4 +1,4 @@
-// Emissive material (light)
+// Emissive material (light)
 MATERIAL 0
 RGB         1 1 1
 SPECEX      0

diff --git a/scenes/cornell_new.txt b/scenes/cornell_new.txt
@@ -0,0 +1,197 @@
+// Emissive material (light)
+MATERIAL 0
+RGB         1 1 1
+SPECEX      0
+SPECRGB     0 0 0
+REFL        0
+REFR        0
+REFRIOR     0
+EMITTANCE   5
+
+// Diffuse white
+MATERIAL 1
+RGB         .98 .98 .98
+SPECEX      0
+SPECRGB     0 0 0
+REFL        0
+REFR        0
+REFRIOR     0
+EMITTANCE   0
+
+// Diffuse red
+MATERIAL 2
+RGB         .85 .35 .35
+SPECEX      0
+SPECRGB     0 0 0
+REFL        0
+REFR        0
+REFRIOR     0
+EMITTANCE   0
+
+// Diffuse green
+MATERIAL 3
+RGB         .35 .85 .35
+SPECEX      0
+SPECRGB     0 0 0
+REFL        0
+REFR        0
+REFRIOR     0
+EMITTANCE   0
+
+// Specular white
+MATERIAL 4
+RGB         .98 .98 .98
+SPECEX      0
+SPECRGB     .98 .98 .98
+REFL        1
+REFR        0
+REFRIOR     0
+EMITTANCE   0
+
+// Camera
+CAMERA
+RES         800 800
+FOVY        45
+ITERATIONS  5000
+DEPTH       8
+FILE        cornell
+EYE         0.0 5 10.5
+LOOKAT      0 5 0
+UP          0 1 0
+
+
+// Ceiling light
+OBJECT 0
+cube
+material 0
+TRANS       0 10 0
+ROTAT       0 0 0
+SCALE       3 .3 3
+
+// Floor
+OBJECT 1
+cube
+material 1
+TRANS       0 0 0
+ROTAT       0 0 0
+SCALE       10 .01 10
+
+// Ceiling
+OBJECT 2
+cube
+material 1
+TRANS       0 10 0
+ROTAT       0 0 90
+SCALE       .01 10 10
+
+// Back wall
+OBJECT 3
+cube
+material 1
+TRANS       0 5 -15
+ROTAT       0 90 0
+SCALE       .01 10 10
+
+// Left wall
+OBJECT 4
+cube
+material 2
+TRANS       -5 5 0
+ROTAT       0 0 0
+SCALE       .01 10 10
+
+// Right wall
+OBJECT 5
+cube
+material 3
+TRANS       5 5 0
+ROTAT       0 0 0
+SCALE       .01 10 10
+
+// Sphere
+OBJECT 6
+sphere
+material 4
+TRANS       1 3 -2
+ROTAT       0 0 0
+SCALE       2 2 2
+
+// Floor
+OBJECT 7
+cube
+material 1
+TRANS       0 0 -10
+ROTAT       0 0 0
+SCALE       10 .01 10
+
+// Ceiling
+OBJECT 8
+cube
+material 1
+TRANS       0 10 -10
+ROTAT       0 0 90
+SCALE       .01 10 10
+
+// Left wall
+OBJECT 9
+cube
+material 2
+TRANS       -5 5 -10
+ROTAT       0 0 0
+SCALE       .01 10 10
+
+// Right wall
+OBJECT 10
+cube
+material 3
+TRANS       5 5 -10
+ROTAT       0 0 0
+SCALE       .01 10 10
+
+// Sphere
+OBJECT 11
+sphere
+material 4
+TRANS       1 3 2
+ROTAT       0 0 0
+SCALE       2 2 2
+
+// Sphere
+OBJECT 12
+sphere
+material 4
+TRANS       1 3 -6
+ROTAT       0 0 0
+SCALE       2 2 2
+
+// Sphere
+OBJECT 13
+sphere
+material 4
+TRANS       1 3 -9
+ROTAT       0 0 0
+SCALE       2 2 2
+
+// Sphere
+OBJECT 14
+sphere
+material 4
+TRANS       1 3 -12
+ROTAT       0 0 0
+SCALE       2 2 2
+
+// Ceiling light
+OBJECT 15
+cube
+material 0
+TRANS       5 5 -5
+ROTAT       0 0 0
+SCALE       .3 0.3 15
+
+// Ceiling light
+OBJECT 16
+cube
+material 0
+TRANS       -5 5 -5
+ROTAT       0 0 0
+SCALE       .3 0.3 15
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
@@ -19,5 +19,5 @@ set(SOURCE_FILES
 
 cuda_add_library(src
     ${SOURCE_FILES}
-    OPTIONS -arch=sm_20
+    OPTIONS -arch=sm_61
     )
diff --git a/src/interactions.h b/src/interactions.h
@@ -76,4 +76,47 @@ void scatterRay(
     // TODO: implement this.
     // A basic implementation of pure-diffuse shading will just call the
     // calculateRandomDirectionInHemisphere defined above.
+	thrust::uniform_real_distribution<float> u01(0, 1);
+	float probability = u01(rng);
+	if (m.hasRefractive) {
+		float costheta = glm::dot(pathSegment.ray.direction, normal);
+		float n1 = costheta < 0 ? 1 : m.indexOfRefraction;
+		float n2 = costheta < 0 ? m.indexOfRefraction : 1;
+		float eta = n1 / n2;
+		float R0 = powf((n1 - n2) / (n1 + n2), 2);
+		float R_theta = R0 + (1 - R0)*powf(1 - glm::abs(costheta), 5);
+		if (probability > R_theta) {
+			pathSegment.ray.direction = glm::refract(pathSegment.ray.direction, normal, eta);
+			if(costheta >= 0) pathSegment.color *= m.color;
+		}
+		else {
+			pathSegment.ray.direction = glm::reflect(pathSegment.ray.direction, normal);
+			pathSegment.color *= m.specular.color;
+		}
+	}
+	else if (probability > m.hasReflective) {
+		pathSegment.color *= m.color;
+		pathSegment.ray.direction = calculateRandomDirectionInHemisphere(normal, rng);
+	}
+	else {
+		// specular reflection
+		pathSegment.color *= m.specular.color;
+		pathSegment.ray.direction = glm::reflect(pathSegment.ray.direction, normal);
+	}
+	pathSegment.ray.origin = intersect + 0.01f * pathSegment.ray.direction;
+}
+
+__host__ __device__
+void scatterRay1(
+	PathSegment & pathSegment,
+	glm::vec3 intersect,
+	glm::vec3 normal,
+	const Material &m,
+	thrust::default_random_engine &rng) {
+	// TODO: implement this.
+	// A basic implementation of pure-diffuse shading will just call the
+	// calculateRandomDirectionInHemisphere defined above.
+	pathSegment.ray.direction = calculateRandomDirectionInHemisphere(normal, rng);
+	pathSegment.color *= m.color;
+	pathSegment.ray.origin = intersect + normal * 0.01f;
 }