Thread by @_Jambax

Using Niagara to draw damage masks with only a single 8-bit render target in @UnrealEngine

Works on skinned meshes and no positional map required, just a single-channel acceleration map baked offline with a custom editor tool. #UE5

Project Discord:
discord.gg/rrMzug9J2n

@UnrealEngine Hits are buffered on CPU and sent to Niagara in batches (up to 64 each-frame), so you can absolutely hammer it with hits.

Takes ~0.6ms for a 1K render target on GTX 980. Next improvement is to prioritise updating within camera view, and atlas targets for different mesh sections.

A custom in-editor tool is used to bake the acceleration data from the content browser.

Specify the mesh, choose the sampling regions abnd UV set, and it packs accordingly. Even shows a preview now :)

There is an upper limit of 65,536 tris - but can be increased to 262,144 by reducing precision of the quantized barycentric data.

Alternatively you can compute pixel barycentric position at runtime, and have >4 million triangles. Good luck skinning a mesh like that though...

Frustratingly - it's impossible to store an R32_UINT texture in Unreal as an asset because silly API decisions, so have to use R32_FLOAT for the acceleration map and asuint/asfloat HLSL intrinsics.

Could fix it by modifying engine, but trying to restrict this to a plugin format.

Looking forward to combining it with this:

https://twitter.com/_Jambax/status/1580323382922424320