Volumetric Path Tracing

The main difficulty lying in implementing heterogeneous volumes. Since the transmittance obtained from the ODE equation is an integral in this case, a clever technique called null-scattering is required to solve this problem. Additionally, implementing multiple importance sampling in this scenario is also a challenging problem.

Monochromatic heterogeneous volume

Colored heterogeneous volume

My own scene

My scenes are all created using Blender.