[Bf-committers] Cycles: Optimizing render speed?

[Kurt Weiss]

Sampling, Path Tracing:
Samples: e.g. 70.

Cycles renders all 70 Samples, regardless of whether the tile is 
changing or not.
Often that's not neccessary in the main parts of the picture...

Maybe it's a idea to add a possibility to define a threshold by 
comparing new an old images of the tile. (e.g. max. change of RGB value 
in pixels)

Especially in areas where only background is present, the engine could 
abort sampling after one or two samples. This would save a lot of time 
at unattended rendering.