UE5, Foliage, and Octahedral Imposters

[Doctor_Kannon]

As we all know, UE5 and Nanite has provided us with massive improvements with respect to the rendering of geometry.

However, Nanite is not currently working with foliage (two-sided materials).

Is there a plan, or roadmap, to address this? Can we expect Nanite to someday work with two-sided materials?

Might UE5 someday generate Octahedral Imposters? Or should we move forward with generating our own OIs?

Thanks!

[Dojo]

It is already possible to generate Octahedral Imposters using Ryan Bruck’s upgraded plugin by Luciano. He made a course about it if you are interested: https://www.udemy.com/course/unreal-engine-octahedral-imposters-create-lod/learn/lecture/22554426#announcements

So far as I understand the limitation with Nanite comes from it unable to handle animation/WorldPositionOffset. While I am hoping there will be improved foliage feautures in the future I am not personally not counting on it. It seems we are still bound to oldskool methods of foliage creation. Keep in mind though that Nanite might open up more rendering budget for foliage so you mind, possibly, not even need to use Octahedronal Imposters.

[Frenetic_Pony]

Eh, there’s a few obvious ways to use nanite with foliage. Not in the way they want, flat runtime performance. But enough to get it working. I wouldn’t be surprised if “nanite skinned/wpo mesh support 0.1” comes out quite soon, maybe even by launch.

You’d still need octahedral impostors though, no getting around that.

[Arkiras]

@Doctor_Kannon

Might UE5 someday generate Octahedral Imposters?

I’ve been hoping to see this integrated with the HLOD generation since it was made… still hoping

[Frenetic_Pony]

@Arkiras

I’ve been hoping to see this integrated with the HLOD generation since it was made… still hoping

Oddly enough they’ve already got it working, just not for foliage. Nanite already auto generates octaherdral impostors for models when they get below 128 triangles in LOD. Would be nice to see that useable elsewhere.

[Doctor_Kannon]

Thank you for the replies.

I have tried Ryan’s and Luciano’s plugins. Also followed Luciano’s Udemy Course. The first pass wasn’t what I had hoped for though.

After this post, I found these Forum threads:

Imposters not working with foliage (no rotation)

It doesnt work, as you load the map, you only get an small plane and it seems like it has material issues, I have the same problems as the original post described, no idea how to keep the Impostor in-place, I followed the documentation but it doesn’t work.

Trying to get Imposters working

The “Full Sphere” version looked like this for me, until I enabled the MIC switch for FullSphere_3.

It seems I’ll need to do some more work on the material shader. With my own shader, it looked like the light/shadows on the trees were coming from a different direction (idea there…). I’ll definitely need to tinker some more.

Hopefully the OI generation currently in-engine will be expanded.

[Dojo]

correct, there are a bunch of problems with Luciano’s shader. The main one is that the sub-surface scattering is somewhat broken. When I have some free time I will look into fixing these shaders and will post them here for those interested