Questions about glowing/emissive decals

Hi everyone,

I am new to Unity, and am attempting to start making a game that involves throwing glowing paint (like Predator blood) on walls.

I am planning on going about this by using ray-casting to determine what surface the paint is "thrown" onto, and then applying a medium size splatter texture onto the surface of contact (no dynamic liquid splatter physics planned yet).

I am still learning about material properties, and I was wondering how to make the paint decal seem like it was glowing.

  1. If I don't need the paint's glow to cast any shadows, is adding an emissive property to the paint material the best way to do this?

  2. If I do want the paint's glow to cast shadows, would spawning a light underneath the paint material be the best approach?

  3. If I want the paint's glow to fade out over 5 seconds, and then have the paint instance to delete itself from the environment after that 5 seconds, is the decal still an appropriate way of adding paint to the world?

Thanks in advance!

  1. Sort of; the best may be to use an "unlit" shader, unless you really need additional lighting on top of the emissive light. Unity 3.2 apparently ships with these, so you may not need to write your own.

  2. Probably. A point light sounds like a good bet.

  3. I think the short answer is "Yes". But I don't know what you mean, by the word "still", in that question.