How to get rid of shadow from transparent area when background lighting only in Cycles I have a scene with a a few planes that have a transparency texture (alpha map) set up. Lighting is done with environment texture only.



Problem is that with 0 diffuse bounces I get shadow action from the planes even at the transparent areas. I am looking for an Cycles only (no compositing!) way to get rid of the shadow action with 0 diffuse bounces.

For comparison, change lighting from background to sun (add sun, remove any input from world output surface, or set background strength to 0.0), and you'll see there is no shadow action from transparent areas of the planes.
After asking around in IRC it turns out this is actually a bug with background light + transparent BSDF.

Reported https://developer.blender.org/T44599