Adding bullet holes that may span UV boundries

RipX · Jul 2011

I'm currently working on my first (properly UV) mapped 3D model. It is very low poly because it is for use in Flash (No molehill, see attachment). I envisage it being used for a multi-player FPS and was thinking about when someone shoots the wall that it would place a bullet hole on the UV but then I started to wonder about what would happen if the bullet hole crossed a UV boundary? My initial thought is, the Bullet hole would appear in multiple places on the building and that would be rubbish.

Obviously I then thought, how would I avoid that and thought about masking the relevant poly but I expect that check could be pretty slow and wondered if there is an 'official' way of going about this?

Thanks for any info

RipX

leechdemon · Jul 2011

My best guess would be to give it a second set of UV coordinates where the entire mesh is uniquely unwrapped, similar to how AO or Lightmaps are often baked. With unique UV's, your seams will always be on polygon edges, not UV edges. Not sure if your system allows that, though.

I've heard of bullets that cast rays, and the bullethole is a decal mapped to a plane, and the plane is projected onto the building wherever the ray is cast. But I have no idea how to actually DO that, though.

Building looks cool, though!

cryrid · Jul 2011

Decals seem to have been the common approach in engines that I've worked with.

RipX · Jul 2011

Yeh, sure, I'm assuming I would draw a decal to the UV texture. But what I'm saying is, when I do that, there is the possibility that the decal would go onto another polys UV data. What I'm trying to figure out is, how do I stop that?!

RipX

Farfarer · Jul 2011

A decal is usually a new, unique piece of geometry that's spawned just above the surface. Whatever's behind it has no effect on the decal itself - the decal just draws on top.

RipX · Jul 2011

@talon, would that mean that the decal could actually float out of your mesh into null space and appear as if floating out of a face!?

RipX

keizza · Jul 2011

it won't appear to float if you offset it from the wall of the building just a teeny weeny nudge.....

locus · Jul 2011

http://www.inlandstudios.com/index.php?show=software.decalcreator

There is a brief explanation of decals on this page as well a trial-ware plug-in for Maya. There is also a video at the bottom of the page that shows how a decal works on another mesh.

Ace-Angel · Jul 2011

locus wrote: »

http://www.inlandstudios.com/index.php?show=software.decalcreator

There is a brief explanation of decals on this page as well a trial-ware plug-in for Maya. There is also a video at the bottom of the page that shows how a decal works on another mesh.

Holy crap, that looks like something out of UDK! Awesome. Wish Max had such a solution, and not the hacky composite material.

Adding bullet holes that may span UV boundries

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