Nanite and smaller meshes

Hi all,

Nanite offers some great options for more (static) dense ground meshes, like moss and ivy. It looks o.k. up close, but when viewed from a distance Nanite crunches the triangles into oblivion until nothing is left. Is there any way around this for meshes like this?

(hiding the floor for clarity)

The moss mesh consists of these cut out ‘cards’. In the background an example of a moss patch.

It’s clear that the meshes are too small screen percentage wise, but isn’t that why you’d want to use UE5 and Nanite? Right now Nanite is doing it’s job a bit too well of crunching the triangles. I understand the moss might be a bit TOO much, but even the ivy leafs have this problem, which are fairly big meshes tbh. I’ve had some challenges trying to get static foliage working with Nanite, but this one I didn’t see coming. Any suggestions how to hack my way around this problem?


Nanite doesn’t work at all with foliage. Use a regular non-nanite mesh with LODs.

Nanite relies on edge collapse decimation to reduce the triangle count, for a regular solid object this works fine because collapsing short edges as you get further from the object doesn’t impact the silhouette much so you are mainly only losing shallow detail that isn’t noticeable from a distance.

For aggregates like foliage it doesn’t work at all, because you very quickly reach a point where all of the geometry is essentially defining the silhouette and nothing can be easily collapsed without destroying the shape. This is why artist crafted foliage is never decimated, instead artists build LODs by removing whole branches and compensating for the loss in foliage density with denser card textures or distance field alpha masks.

I’m gonna just bash my head against the wall until it works. I want more dense foliage, actual moss. It has to work somehow. We can make an entire death star with greeble everywhere but moss is rocket science, I just don’t like it lol. I’ll figure something out.

It does, just use a non-nanite mesh…

I can get away with that for the ivy no problem/ My non-nanite mesh for the moss patch placement is…151k tris. Don’t really want to spam that around 1000x in the scene :stuck_out_tongue:

thats what LODs are for

specifically HLODs for nanite objects, it can combine multiple meshes into a single nanite mesh and then reduce that down, so no tiny skinny tris

Nanite foliage support is planned, but no timeline has been revealed.

Tried the regular LOD’s just now, as expected minus 15 FPS for just those 3 square meters.

This mostly just tells me you need to build more efficient LODs…

Nope. One moss patch at LOD0 is 133k tris. At LOD4 they’re 8k tris. But up close there’s about 30 placements that render at LOD0. That’s around 4 mil triangles. For 3 square meters. Now let’s multiply this by 10, the total area of the floor I’d like to cover. I appreciate the help but I think LOD’s are not the solution for what I’d really like to achieve.

Some random duplication for the amount of instances I would need. Visually this looks cool for screenshots, but that FPS is hurting my soul… (at 45 down from ~80)

I tried this, during compilation it just gave me a bunch of errors and build nothing, hopefully they’ll fix something like this further down the line, sounds interesting with Nanite in mind.

I personally can’t wait. I hope they don’t release UE5 before implementing it, for environment artists it’s almost a must have.

Use a flat mesh w/bump offset on the material. Cheaper, and I doubt you would be up against the moss so close you would notice. As well, since it would be texture-driven you can muck with the resolution of the thing as much as you want.

hmm yes I agree that tends to look nice, this time I’d really like to be able to “paint” meshes on other geometry to really give it that silhouette that moss van give. Something not so flat with silhouette and volume.


Yes 8k. That is all, in the land where meshes can be millions of triangles 8k is nothing. I want realistic moss, not the way we’ve done things in the past. Welcome to the future.

You have two options:

  1. Make your content more efficient. Either by achieving moss a different way or by making better use of your geometry.
  2. Wait indefinitely for the future to arrive and hope that a solution for aggregates is found/created for Nanite

Technically I guess you also have the third option of just eating the performance hit.

  1. You’re not gonna make me give up, but thanks for your input :wink:

That’s option 2