I know there is a free decal system but i would like to make it on my own and though i know how to use decals with planes in walls i would like the decals follow the surface of the bumped shader in wall or follow irregular mesh shapes. I tried using projector decal shader but the image shown has not the same color as using the decal with a plane and it repeats a pattern all along the wall and not just one decal.
The aim is get something similar to this First blood part 2 - Wolfire Games Blog
I already pointed you to my Decal System with its Projection Modes. But in the case that someone is looking for an answer to that questions, I’ll answer it here as well.
You can specify the needed projection mode on your own as demonstrated in this video: http://www.youtube.com/watch?v=4cEnbPYDG8M
This allows you to take the bump of the object onto which the decal projection happens into account, certainly only with the appropriate shader/projection mode combination.
The animation can be handled in many ways, be it though a uv animation or another technique, which is a different topic, but can certainly be solved.