A GPU Path Tracer written in CUDA C++ with BVH acceleration.

This 512 x 512 Cornell Box with 500 samples per pixel took 109 seconds to render.

Features:

• Parses a scene in Mitsuba XML file format.
• GPU Path Tracer (with global illumination) using CUDA.
• Implements a BVH acceleration structure.
• Support for spheres and triangle meshes.
• Support for diffuse, mirror, plastic, Phong materials (with Fresnel reflection).
• Anti-aliasing, Russian Roulette termination.
• Exports the scene into a png file.

Running the code

1. To compile, use the command:

make

in the home directory. (If the program cannot find CUDA, adjust the CUDA_PATH in the Makefile)

2. After compiling, use the command:

./torrey scenes/spheres/scene1.xml

'scenes/spheres/scene1.xml' after ./torrey is just an example. Additional scenes can also be rendered. The xml file can be located in various folders within the ‘scenes’ folder like:

./torrey scenes/cbox/cbox.xml

The resolution and sample size can be adjusted by changing the values of the xml files.

3. The rendered image can be found in the 'output' folder under the name 'img.png'!

Tested on:

• System: Ubuntu 23.04
• CPU: Intel i7-13700k
• GPU: RTX 3080
• Nvidia Driver Version: 535.86.10
• CUDA Version: 12.2

More sample images!

Spheres_Scene1 (Diffuse and Phong spheres)

640 x 480 pixels with 500 samples per pixel. Render time: 10 seconds

Buddha

640 x 480 pixels with 500 samples per pixel. Render time: 44 seconds (The Buddha has 1087474 triangles)

Party (Bunny, Buddha, Armadillo, and Dragon)

640 x 480 pixels with 500 samples per pixel. Render time: 310 seconds
(The bunny has 144046 triangles, the dragon has 871306, and the armadillo has 212574)