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SM with lots of poly vs. lots of SM and less poly

Hello everyone,

I’m trying to add some pebbles all over an area of my map, and for that I have plenty of little pebbles meshes.

But I’m wondering, as I’m going to use the foliage tool to instance them, should I regroup all of these pebbles into one big static mesh and place that static mesh on my map, or should I have one static mesh per pebble and paint them all over my map with the foliage tool?
What way is the most efficient?

Thanks!

I would use low poly pebbles which will be placed with the foliage tool -> the foliage tool renders them in clusters + culling is easier + it’s more flexible

Thanks.

What is the advantage of rendering it in clusters?

Also I just tried to render a mesh with the foliage tool and I notice the LOD doesn’t apply… It’s always rendering the LOD0 even when I’m far away from it.
LOD doesn’t work with the foliage tool?

LOD: https://forums.unrealengine.com/showthread.php?9629-Foliage-brush-and-LOD-meshes&highlight=foliage+lod

It gives you a better performance because it renders those clusters in a single draw call.

So I think the problem comes from the fact that I’m using different UV between LOD 0 and 1…

For my LOD, I firstly import my high poly mesh, then open it in the SM Editor in UE4, and click Import LOD Level 1. But they have different wrapping.
Is there a way to have both LOD0 and LOD1 in a single fbx file? In the import option there is a “Import mesh LODs” but I don’t know how to use it and I can’t find any docs about it… :frowning:

Just export the different LOD stages as a separate fbx file: http://www.youtube.com/watch?v=17pcyPVplEc and then impor them over the “impoet mesh lods” button (in the video I show the entire process)

Well, that’s what I’m actually doing for my different LOD. But as Tim Hobson said here https://forums.unrealengine.com/showthread.php?9629-Foliage-brush-and-LOD-meshes&p=75116&viewfull=1#post75116 :

My two LOD meshes doesn’t have the same Unwrapping because I’m using the Decimate tool in Blender to create a low poly one and it generates different UVs.
How can I have both meshes have the same UVs?

In 3Ds Max there is a way to save the UV unwrap as a file and import that to apply it to another mesh.

I found a video that explains how to do this in Blender. I don’t use Blender so this version may be different or have outdated features.

Hopefully this helps!

Tim

https://youtube.com/watch?v=E6LVWYFpp3U

Decimate tool respects UVs to the best of its abilities. It may look different, and end up losing some of the texture detail, but for a LOD mesh, it should be acceptable. Light and shadowmaps in this case shouldn’t matter as much, as UVs are still in the general vicinity, shading errors should be minor.