This is the second installment about the light settings.
In the Light Paths panel of the render tab, right beside the No Caustics check box there are other settings that can cut a bit from the realism of the lighting scheme in favor of a faster render. Setting the max bounces to a lower value like 4 might not be so noticeable for some scenes, and depending on the shaders used, you can adjust separately the bounces for diffuse, transmission or glossy light paths.
We’ll find another light related setting in the Materials tab. You can check off a setting called Multiple Importance Sample for shaders on objects that might not be relevant contributors of light in the scene. In previous Blender releases including 2.65 this was called Sample as Lamp which sounded intelligible but obviously was not so accurate since it was replaced by the more puzzling new name. Objects can also have some light calculations removed in the Ray Visibility panel in Object tab.
Let’s also take a look at the dark side of light: trying to fake shadows with a soft natural look in Blender Internal can cost time. Increasing the raytraced shadows soft size gives a nice realistic effect but it can look too grainy unless the samples setting goes up. To speed things, you might consider testing several sample values so not to go overboard, or just work with the default setting of 1 sample – size 1 and crisp raytraced shadows. You can also take a look at the buffer shadows option available for some type of lamps.
In Cycles, shadows don’t come with their own settings as they are not “faked” and are naturally soft. There is render time loss lurking in the shadows though, as areas poorly lit tend to generate a lot of noise and will need more passes to render.
Do you have any other tips? Share them in the comments below.
