Laser

A GPU path tracer in C++/OpenCL.

Sample Output

Note the following:

• Reflected green light from the wall (wall not in view)
• Interpolated smooth shading across the surface of the teapot (you can still see the low resolution of the model by looking at the jagged silhouette)
• Depth of field / blurred background (easily visible if you look where the walls meet or at the handle of the teapot)

Render info:

Device: AMD Radeon RX 570
Triangles: 1,006
Render time: 4 minutes 49 seconds
Image size: 600x600
Samples per pixel: 4096
Max ray depth: 8 bounces
*Note: output was in .ppm, converted to .jpeg to display here

Features

• High levels of parallelism using GPU
• Direct and indirect lighting (global illumination)
• Triangle primitives (polygon primitives also supported through Assimp importer)
• Loading triangle meshes from external files
• Multiple objects in scene
• Transformation using translation, rotation, scale
• Physically based camera model with adjustable vFOV, focus distance, defocus blur (depth of field)
• Bounding Volume Heirarchy (BVH) acceleration structure
  • Automatic construction on CPU
  • Stack-based traversal on GPU
• Various materials
  • Diffuse
  • Metal
  • Glass
  • Area lights
• Smooth shading / soft shadows
• Adjustable samples per pixel for anti-aliasing and decreased noise
• Image output to .ppm

Next steps

Planned features include:

• Build system
• Scene description format (so different scenes can be rendered without modifying code)
• Textures
• HDR
• Tone mapping
• Surface Area Heuristic (SAH) BVH construction