Unbiased Volumetrics

We just finished implementing full unbiased volumetrics with multiple scattering in the PathTraceIntegrator.
Here is a image rendered using the metropolis sampler. Please note the halo around the lights and the god-rays coming through the plant on the left. As usual you can tweak all the properties of participating media in real-time.
Volumetrics will be available starting from release 0.9.9.