2.30
Filter: Emission

- 2.30.1. Overview
- 2.30.2. Algorithm
- 2.30.3. Types

2.30.1
Overview
1
An emissive surface is a surface that appears to emit light. The r2 package offers emission as a visual effect implemented as a filter. An optional glow effect is provided to allow emissive surfaces to appear to have a configurable aura.
2
The emission effect is obviously not physically accurate - surfaces do not really emit light. The user is expected to make intelligent use of the standard light sources to provide lighting, and to use the emission effect to complement them.
2.30.1.3 Emission
2.30.2
Algorithm
1
The plain emission effect without glow is implemented as trivially as possible by sampling the emission value from a rendered scene's geometry buffer, multiplying it by the albedo color and then simply adding the result to the current pixel color.
2
The emission effect with glow is implemented similarly, except that the albedo * emission term is stored in a separate image, and that image is blurred with a configurable box blur before being additively blended over the original scene. Higher levels of blurring can give the impression of a dusty atmosphere.
2.30.2.3 Emission (Glow)
2.30.3
Types
1
In the r2 package, the emission effect is provided by the R2FilterEmission type.