Blender Dokumentation: Composite-Nodes/ Color/ Gamma

Diese Seite bezieht sich auf Blender v2.49

In 2.50 gibt es den linearisierten Workflow. Da schreibe ich dann was über Gamma. Jetzt macht es wenig Sinn.

Anwendung

The reason for applying gamma correction to the final render is to correct lighting issues. Lighting issues that are corrected by the gamma correction are light attenuation with distance, light falloff at terminators and light and shadows superpositions. Simply think about the renderer as a virtual camera. By applying a gamma correction to your render, you are just replicating what digital camera do with the photos. Digital camera gamma correct their photos so you do the same thing. The gamma correction is, indeed, 0.45. Not 2.2.

But the reverse gamma correction on the textures and colors have another very important consequence when you are using rendering techniques such as radiosity or GI. When doing the GI calculations, all textures and colors are taken to mean reflectance. If you do not reverse gamma correct your textures and colors, then the GI render will look way too bright because the reflected colors are all way too high and thus a lot more light is bouncing around than it should.

Gamma correction in Blender enters in a few places. The first is in this section with the nodes, both this node and the Tonemap node, and the second is in calculating Radiosity. In the noodle to the left, the split viewer shows the before and after effect of applying a gamma correction.