The emission allows parts of the shader to glow, even when there's no light. |
Standard Standard emission works pretty simply. After the lighting has been calculated and applied to the diffuse, emission is added on top. |
Multiply Multiplyed emission has the emission multiplied by the diffuse color before being added. |
Set Set emission works very differently to the others. It mixes the Emission on top of the diffuse, but continues to be shadeless. This lets you do things like cell shading or outlines. |