I’ve got the image below. The K is created with a texture, not geometry. I’d like to get the K glowing with some kind of composite node, but am having trouble figuring out how to isolate the K from the rest of the object.
If you want it to actually emit light, you could make a grayscale version of the image and set it to affect the “Emit” parameter. Yeah hrmmm. How to isolate the K. I dunno.
For isolating of “K”: You can try something like Chroma Key to separate by color, or try to decompose to three different chanels: Red, Green, Blue - then use blue channel to make blur/glow effect then “add/lighten” this image to original one.
Another thing you could do is separate the K from the rest of the object and put it onto a different render layer than give it some glow and composite it back into the final.