From my understanding, there are several different ways to implement decals, from screen space, to copying geometry, but I can never find an explination of it's math.
So what exactly is the math about Decal geometrical projection? I understand that it's dependent on some set of UVs to be projected, which is generated by clipped triangle coordinates, and meant to only be used on statics.
How does the Screen Space projection work exactly?
And I understand that the two previous methods do not work on dynamic geometry, (say you want a bullet wound on a character), how is that solved?