I am pretty new to 3D and I was hoping someone could help educate me on something.
I have been working through “Blender 2.6 Cycles: Materials and Textures Cookbook”. As I was going back through the setup after changing to 2.7 I noticed that “Clamp” is now 2 different settings, “Clamp Direct, and Clamp Indirect”.
I was wondering if someone could explain the difference between the two of them, and how those 2 differ from the original “Clamp” setting?
If you’re still having trouble, basically Clamp Direct will clamp the intensity of pixels being hit directly by light sources. This means bright highlights and reflections. Generally you won’t want to clamp this value much, if at all, as these values are important to a linear color pipeline and post production/comp. Indirect clamping will clamp pixels being hit by reflected light. This is a VERY handy tool to have for most scenes. Light paths that bounce from glossy to diffuse multiple times are difficult to resolve and often cause ultrabright pixels or fireflies that will take many passes to average out to a correct result afterwards. Things like hair, materials with fresnel interreflections, and the like are especially prone to this. Clamping this value will ensure that you don’t get any accidental bright pixels during sampling, while also ensuring that you’re not measurably affecting the dynamic range of the final image as a whole.