texturing ruined walls

nome_sane

I'm trying to find a good way of creating nice ruined walls. But be able to cut in the damage arbitrarily. The way I am approaching this at the moment is with tiled textures as in the diagram but obviously you get quite ugly seams.

It looks cool in the distance but this is for an fps so you can get up close to the wall. I was thinking I could use a blend shader on the strip of damage but that, I guess would be relatively expensive.

Does anyone know better ways to do this kind of thing?
Any thoughts would be much appreciated.

Joshua Stubbles

You'll never a true ideal blend when using 2 textures like that. But it's better for memory, so..

You can try blending or using decals.

With texture blending, you can use either vertex coloring (cheap but depends on # of verts for quality of blend) or a blend map using another UV channel (more expensive but gives you per pixel blend control).

For decals, Fallout3 is a great example. Roughly 90% of all of their chipped/broken edges are nothing more that normal mapped decals with alpha. It's a convincing trick from a distance, but it's very obvious the closer you get. But in all honesty, the average player will neither care nor notice.

Or you can just suck it up and deal with it
Even Metal Gear 4 and Gears of War have walls with seams like that. It's a normal part of env work, and unavoidable at times.

StrangeFate

Assuming you can use whatever technique you want (custom texture excluded), I'd go with vertex blending.
If you only want to have 1-2 broken walls then i'd maybe even think about using a custom texture, you could even use a tiling texture on the not broken part and then make a custom strip with the broken look that blends into the tiling one.

If you want to have lots of random broken walls then blending is the fastest and most flexible approach I'd say. The additonal geometry you need wont do much of an impact anywhere.

nome_sane

Thanks for getting back to me guys. I've not had a chance to look at fallout yet but I know the kind of thing your talking about and I'll look into it.
I would guess MGS4 and gears can get away with it a bit more being 3rd person. I think I will let it slide in less obvious areas the player cant get up close to but neaten it up in more important places either with blending or decals.

It would definitely give the nicest results using bespoke damage sections. But I am really looking for a method where I can be very free about where I create damage like across arches and places like that.

If the shader isn't too expensive, vertex blending sounds like a good option. The blend doesn't need to be perfect as long as there isn't a really harsh seam which attracts the players attention.

Thanks again.