How do I make only some parts of my texture emissive?

Hi guys, i have a model with some part solid color and the other one a “Ligth” Part when you place the texture on the model its doing cool but you see the “Ligth” part opaque(because doesnt have emissive properties) im tryin to make this part emissive but keeping the solid color intact… i think with a subtract from this maps will work but what you think guys?

Use a black and white mask and feed both the lit color texture, the diffuse color texture and the mask (alpha) texture through a LERP node in the material

Diffuse input:


A : Color of object

B : Color of Glow

Alpha : Mask

Emissive input:

Mask multiplied by glow color 3 constant or texture - black parts give a result of 0 therefore no glow there.

You may also wish to set your model up with 2 elements, each element can have a different material applied to it.

The method for doing this will vary depending on the art package you use - eg in blender: set the emisive bits to have a seperate material to the main body.

This method is less efficient than the masking method when it comes to rendering the model, however it can be useful for ease of setting up the model and for dynamicaly altering materials more easily.

eg. engines or thrusters having an emisive component which is controled via parameters to effect the glow and colour.