ray-tracer

A basic ray-tracer in C that implements BVHs and SBVHs, using a fully parallelized approach.
It doesn't support reflections, materials or even textures however. Triangles are rendered in greyscale using smooth shading.

The parser only supports wavefront (.obj) triangulated meshes. It might not support all variants of this format though. If your mesh does not render correctly, try importing it to Blender and exporting it again.

Basic usage

The first command line argument expects the path to .obj file. From then, the program works like a CLI. There are two commands:

• render [args] is used to generate an image of the scene (in output.ppm). Arguments:
  • bvh enables the use of a BVH to speed up the rendering process (will error if the bvh command wasn't used beforehand).
  • heatmap generates a heatmap in addition to the render (in heatmap.ppm).
  • red=n (where n is an integer) sets the hit threshold beyond which pixels get bright red on the heatmap.
  • Any other argument will be interpreted as the path to a render configuration file.
• bvh [args] is used to generate a BVH for the scene. It is then saved for all future renders. Arguments:
  • spatial enables the use of spatial splits.
  • output creates a mesh of the BVH (in bvh.obj).
  • alpha=f (where f is a float between 0 and 1) sets the alpha parameter for spatial splits.

Example config file

The camera position is defined using spherical coordinates, whose center is FOCUS. Angles are expected in degrees.

RATIO: 3/2
IM_H: 400
VP_H: 1
FOC_L: 1
FOCUS: 0.5 0.5 0.5
R: 3
THETA: 90
PHI: -90