Question: DX 11 Mesh deformation based on a "decal" with a heightmap

Skamberin

So yeah, I was just thinking about if it is possible to have a mesh in UDK with DX 11 tesselation, base part of its deformation on a decal applied anywhere on it's body.

Like say you fire a gun onto a wall and the decal simulates a mesh altering impact by altering the geometry of the mesh in just THAT area, giving the decal more depth.

Or say you use a sharp melee weapon on an un-armoured enemy to get deep cut wounds.

Would something like this be achievable? And if so, any ideas on how?

It might be overkill on hardware, but from what I've seen of DX 11 you should be able to allocate a higher resolution of tesselation onto different parts of a mesh, which would mean that only part of the mesh is highly tessellated to better present the "damage".

It's just something I wondered about, playing Half Life 2 lately made me realise that the good ol' impact shots have mostly vanished from FPS games, and what better way to re-introduce them then this :P

Oniram

i actually thought about this for something today. i was wondering if it were possible to shoot at something (say an oil drum.. to be generic), and the drum gets deformed after you shoot it. i was gonna give it ago at some material and scripting for that but got caught up in something else. generally i think it is possible, but probably quite difficult

roosterMAP

you dont need tessellation for a decal. As long as u dont really need an occlusion, a normal map should suffice.

Visceral

Oniram wrote: »

i actually thought about this for something today. i was wondering if it were possible to shoot at something (say an oil drum.. to be generic), and the drum gets deformed after you shoot it. i was gonna give it ago at some material and scripting for that but got caught up in something else. generally i think it is possible, but probably quite difficult

I think this was done in one of the early PhysX tests, its deffinatly possible to do at runtime. However why dont you just try make a decal with tesselation applied to it?

As far as i know UDK decals work with both parallax maps and normal maps so why dont you go ahead and try?

Oniram

i will.. ill do just that.

A. Rabbit

I want to test this out as well when I get a new gfx card, you can achieve a similar effect using a parallax occlusion decal shader.

Skamberin

It'd honestly be very interesting to see this working on a character, if someone figures out how to do it with regular decals on static meshes, it could in theory be possible on rigid bodies actors and the like, where it would obviously shine the most.

JordanW

Not possible without a lot of code work. Decals are just duplicate geometry on top of existing geometry so you couldn't punch something in without getting rid of the existing geometry or masking it somehow. You could build your deformations into your base shader though and have a mask (vert color or textures) dynamically modified by code.