Source/Render/Cycles/Volume

= Volume Render =

To Do

 * Support BSDFs in volumes
 * Material density output (like displacement)
 * Gradient of density field = normal, compute like bump mapping


 * Multiple scattering approximation with octaves
 * Use ray differentials for volume shading


 * Verify lamp MIS correctness with volumes and mix of surfaces and volumes.


 * World volumes
 * Do we need an option to exclude the world volume from the interior of objects? Some more general mechanism?
 * Very low density should not be optimized out for closures, now there is a discontinuity.


 * Incorrectly connnected surface shader to volume socket: detect and ignore?


 * Random jitter offset for heterogeneous volumes can use stratified samples
 * Add a user setting for transparency cutoff, as optimization and to make creating opaque volumes possible without infinite density.
 * Ray visibility (partially there)