Project3: Jinxiang Wang

.gitignore

@@ -4,7 +4,7 @@
 *.vcxproj
 *.xcodeproj
 build
-
+*/hdri
 # Created by https://www.gitignore.io/api/linux,osx,sublimetext,windows,jetbrains,vim,emacs,cmake,c++,cuda,visualstudio,webstorm,eclipse,xcode
 
 ### Linux ###
@@ -23,7 +23,8 @@ build
 .LSOverride
 
 # Icon must end with two \r
-Icon
+Icon
+
 
 # Thumbnails
 ._*

CMakeLists.txt

@@ -43,7 +43,12 @@ else(UNIX)
 
     add_definitions(${GLEW_DEFINITIONS})
     include_directories(${GLEW_INCLUDE_DIR} ${GLFW_INCLUDE_DIR})
-    set(LIBRARIES ${GLEW_LIBRARY} ${GLFW_LIBRARY} ${OPENGL_LIBRARY})
+
+    set(OIDN_ROOT_DIR ${EXTERNAL}/oidn)
+    include_directories("${OIDN_ROOT_DIR}/include")
+    link_directories("${OIDN_ROOT_DIR}/lib")
+
+    set(LIBRARIES ${GLEW_LIBRARY} ${GLFW_LIBRARY} ${OPENGL_LIBRARY} OpenImageDenoise)
 endif(UNIX)
 
 set(GLM_ROOT_DIR "${CMAKE_SOURCE_DIR}/external")
@@ -61,6 +66,15 @@ set(headers
     src/sceneStructs.h
     src/preview.h
     src/utilities.h
+    src/tiny_obj_loader.h
+    src/PTDirectives.h
+    src/bvh.h
+    src/texture.h
+    src/memoryArena.h
+    src/cudaUtilities.h
+    src/light.h
+    src/pbr.h
+    src/disneybsdf.h
 )
 
 set(sources
@@ -74,6 +88,10 @@ set(sources
     src/scene.cpp
     src/preview.cpp
     src/utilities.cpp
+    src/tiny_obj_loader.cpp
+    src/bvh.cu
+    src/texture.cu
+    src/cudaUtilities.cu
 )
 
 set(imgui_headers
@@ -128,3 +146,20 @@ target_link_libraries(${CMAKE_PROJECT_NAME}
 target_compile_options(${CMAKE_PROJECT_NAME} PRIVATE "$<$<AND:$<CONFIG:Debug,RelWithDebInfo>,$<COMPILE_LANGUAGE:CUDA>>:-G;-src-in-ptx>")
 target_compile_options(${CMAKE_PROJECT_NAME} PRIVATE "$<$<AND:$<CONFIG:Release>,$<COMPILE_LANGUAGE:CUDA>>:-lineinfo;-src-in-ptx>")
 set_property(DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR} PROPERTY VS_STARTUP_PROJECT ${CMAKE_PROJECT_NAME})
+
+
+# add_custom_command(TARGET ${CMAKE_PROJECT_NAME} POST_BUILD
+#     COMMAND ${CMAKE_COMMAND} -E copy_if_different
+#         "${CMAKE_SOURCE_DIR}/external/oidn/bin/OpenImageDenoise.dll"
+#         $<TARGET_FILE_DIR:${CMAKE_PROJECT_NAME}>
+#     COMMAND ${CMAKE_COMMAND} -E copy_if_different
+#         "${CMAKE_SOURCE_DIR}/external/oidn/bin/OpenImageDenoise_core.dll"
+#         $<TARGET_FILE_DIR:${CMAKE_PROJECT_NAME}>)
+
+file(GLOB OIDN_DLLS "${PROJECT_SOURCE_DIR}/external/oidn/bin/*.dll")
+foreach(DLL ${OIDN_DLLS})
+    add_custom_command(TARGET ${CMAKE_PROJECT_NAME} POST_BUILD
+                       COMMAND ${CMAKE_COMMAND} -E copy
+                       "${DLL}"
+                       "$<TARGET_FILE_DIR:${CMAKE_PROJECT_NAME}>")
+endforeach()

README.md

@@ -1,13 +1,158 @@
-CUDA Path Tracer
-================
+# 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)
+- Jinxiang Wang
+- Tested on: Windows 11, AMD Ryzen 9 8945HS w/ Radeon 780M Graphics 4.00 GHz 32GB, RTX 4070 Laptop 8 GB
 
-### (TODO: Your README)
+## Results Preview:
 
-*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.
+![](results/Cover/CoverDenoisedMIS.png)
 
+<p align="center">A large mineway castle shaded with one Disney BRDF material (6,490,766 triangles, 300 spp, 6.1 fps)</p>
+
+![](results/RefractDragon.png)
+
+<p align="center">A stanford dragon shaded with refract material</p>
+
+## Features Implemented:
+
+1. Bounding Volume Hierarchy (HLBVH)
+2. Disney DRDF model (not fully correct in some cases)
+3. GUI for dynamic material modification
+4. Muiti-Importance Sampling
+5. ACES Tone Mapping
+6. TinyObj mesh loading
+7. Environment Map
+8. Stocastic Sampled Anti-Aliasing
+
+# Bounding Volume Hierarchy
+
+The base code shoots rays out from the camera and compute intersections with all objects in the scene.
+
+This works fine when we can implicitly define intersecting method for each geometry (just like SDF). But after mesh loading feature is implemented, the way of light-scene intersection is changed from calculating
+intersection with implicit geometries to calculating it with all triangles!
+
+This gives an extremely low performance when model with many faces is loaded:
+
+| < 200 faces (~60 fps)            | ~6000 faces (< 10 fps)          |
+| -------------------------------- | ------------------------------- |
+| ![](results/BVH/simplescene.png) | ![](results/BVH/marioScene.png) |
+
+To effectively reduce the amout of intersection computation, we could use BVH, Bounding Volume Hierarchy, which construct
+a tree-like structure to store scene primitives.
+
+The efficiency of BVH depends on how we build the tree. There are many ways to segment triangls, for this project, I used HLBVH, which is a combination of Surface Area Heuristic (SAH) and morton code based Linear BVH. For more reference, check [PBRT 4.3 Bounding Volume Hierarchy](https://pbr-book.org/3ed-2018/Primitives_and_Intersection_Acceleration/Bounding_Volume_Hierarchies).
+
+And this gives a very good speed up
+
+| Before BVH (< 10 fps)           | After BVH (~30 fps)           |
+| ------------------------------- | ----------------------------- |
+| ![](results/BVH/marioScene.png) | ![](results/BVH/AfterBVH.png) |
+
+We can go even further with a stanford dragon (2,349,078 triangles)
+
+| Dragon ( 15 fps)            |
+| --------------------------- |
+| ![](results/BVH/Dragon.png) |
+
+Visualizer:
+
+| Wahoo                    | Dragon                         | Mineway Castle                |
+| ------------------------ | ------------------------------ | ----------------------------- |
+| 5117 triangles           | 2,349,078 triangles            | 6,490,766 triangles           |
+| ![](results/BVH/BVH.png) | ![](results/BVH/DragonBVH.png) | ![](results/BVH/CoverBVH.png) |
+
+# Disney BRDF Model
+
+This is a robust and art-oriented material model that allows for interpolation between different types of material based on pbr parameters. The model implemented in this project referenced SIGGRAPH 2012 [Physically Based Shading at Disney](https://media.disneyanimation.com/uploads/production/publication_asset/48/asset/s2012_pbs_disney_brdf_notes_v3.pdf) by Disney and their public repo [brdf](https://github.com/wdas/brdf/tree/main)
+![](results/DisneyBRDF/presentation.png)
+
+The input parameters are given by:
+
+color baseColor .82 .67 .16  
+float metallic 0 1 0  
+float subsurface 0 1 0  
+float specular 0 1 .5  
+float roughness 0 1 .5  
+float specularTint 0 1 0  
+float anisotropic 0 1 0  
+float sheen 0 1 0  
+float sheenTint 0 1 .5  
+float clearcoat 0 1 0  
+float clearcoatGloss 0 1 1
+
+| Input Format
+| ------------------------------------- |
+| ![](results/DisneyBRDF/jsonInput.png) |
+
+GUI allowing for dynamically changing parameters:
+
+| GUI                             |
+| ------------------------------- |
+| ![](results/DisneyBRDF/GUI.png) |
+
+A brief demo illustrates the usage:
+
+https://github.com/user-attachments/assets/62e0fcce-20bc-49f6-b9c6-eea6904767dc
+
+# Direct Lighting & Multi-Importance Sampling
+
+Consider the following 2 scenarios:
+
+1. When light is very small in size
+2. When we want to implement point light/directional light/spot light
+
+When light is small in size, it is less likely for a diffused BRDF to gather meaningful light contribution.
+Therefore, each time when a ray hits a surface, we can consider sampling radiance directly from a light in the scene.
+This way of calculating radiance contribution is called direct lighting.
+
+The direct radiance from different sample point:
+
+| Direct Lighting Radiance        | Accumulative Color (depth = 1)  |
+| ------------------------------- | ------------------------------- |
+| ![](results/MIS/DIRadiance.png) | ![](results/MIS/accumColor.png) |
+
+But direct lighting behaves poorly when sampling from a large area light.
+
+Veach Scene:
+
+| BSDF Lighting                | Direct Lighting            | MIS Lighting                  |
+| ---------------------------- | -------------------------- | ----------------------------- |
+| ![](results/MIS/MISBSDF.png) | ![](results/MIS/MISDI.png) | ![](results/MIS/MISVeach.png) |
+
+So a good practice might be to combine the two method, which is the main idea of Multi-Importance Sampling. To ensure energy-conserving contribution, we use Power Heuristic to calculate the appropriate weight for the directional light radiance.
+
+Also by having an additional directional light contribution, we can acchieve a faster convergence. In order to make a correct contribution to our final color. At each bounce, multiply the sampled radiance with corresponding throughput (radiance `*` accumThroughput `*` BSDF(wo, wdirect)).
+
+Some results:
+
+| MIS On                     | MIS Off                     |
+| -------------------------- | --------------------------- |
+| ![](results/MIS/MISOn.png) | ![](results/MIS/MISOff.png) |
+
+### Tone Mapping
+
+---
+
+Applying ACES Tone Mapping
+
+| ACES Off                      | ACES On                      |
+| ----------------------------- | ---------------------------- |
+| ![](results/ACES/ACESOff.png) | ![](results/ACES/ACESOn.png) |
+
+### Stocastic AA
+
+---
+
+| AA Off                     | AA On                    |
+| -------------------------- | ------------------------ |
+| ![](results//beforeAA.png) | ![](results/afterAA.png) |
+
+### Denoiser (Intel® Open Image Denoise)
+
+---
+
+| Denoiser Off                          | Denoiser On                             |
+| ------------------------------------- | --------------------------------------- |
+| ![](results/Cover/CoverNoDenoise.png) | ![](results/Cover/CoverDenoisedMIS.png) |