# Fracturing Nanite Meshes

**URL:** <https://forums.unrealengine.com/t/fracturing-nanite-meshes/2420606>\
**Category:** Asset Creation\
**Tags:** unreal-engine, Destructible-Mesh, UE5, Nanite, fracture\
**Created:** [March 27, 2025, 3:35am UTC](https://forums.unrealengine.com/t/fracturing-nanite-meshes/2420606 "2025-03-27T03:35:03Z")\
**Posts on this page:** 11\
**Page:** 1

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**Author:** ![D\_Siggs3](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@D\_Siggs3](https://forums.unrealengine.com/u/D_Siggs3)\
**Post date:** [March 27, 2025, 3:35am UTC](https://forums.unrealengine.com/t/fracturing-nanite-meshes/2420606/1 "2025-03-27T03:35:03Z")

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What is the current consensus on using Chaos Fracture with Nanite? I want to hear about other developers’ experiences in this.

Using 5.4.4, when I fracture a nanite mesh, the materials revert to world default, and the material options in the fracture editor has no effect in restoring or reassigning them.  
Also, I cannot select pieces of the fractured nanite geometry like I can with non-nanite geometry. I can only select the whole mesh, so adding additional fracturing to pieces is not possible.

I’m only just starting to get used to the chaos fracture tools, so perhaps there is a step in the process that I’m not aware of.

What are some of the issues other people have had using fracture with nanite?

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**Author:** ![CedUE](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/cedue/32/924243_2.png) [@CedUE](https://forums.unrealengine.com/u/CedUE)\
**Post date:** [March 29, 2025, 10:02pm UTC](https://forums.unrealengine.com/t/fracturing-nanite-meshes/2420606/2 "2025-03-29T22:02:46Z")

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Hi

Material should be working fine with nanite geometry collections  
Have you check that your material has the “use with nanite” option checked?

If so, is your material transparent?  
As far as I remember the geometry collection renderer only support opaque or masked materials when nanite is on

Regarding the selection, this is a known issue  
The selection works, ( you can see it changing in the bone hierarchy in the fracture editor ) but the selection overlay does not work with nanite rendering  
you could disable nanite temporarily on the geometry collection asset as a work around  
( there’s a check box in the asset properties for that )

I hope this helps

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**Author:** ![SpareHexGames](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@SpareHexGames](https://forums.unrealengine.com/u/SpareHexGames)\
**Post date:** [March 30, 2025, 1:09pm UTC](https://forums.unrealengine.com/t/fracturing-nanite-meshes/2420606/3 "2025-03-30T13:09:11Z")

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I did some fiddling around and managed to accomplish piece selection from the fracture editor list. This solves one of the issues that I encountered.

I also managed to get the assigned materials to show up. The viewport just wasn’t reflecting the changes until the object was clicked on again (I guess clicking an object refreshes or reaquires its attributes?)

The remaining issue (and most pressing one) is that the interior materials wont assign to the interior faces. I’ve tried to set the index at the moment of fracture, and in the fracture material editor, but it doesn’t seem to have any effect.

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**Author:** ![CedUE](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/cedue/32/924243_2.png) [@CedUE](https://forums.unrealengine.com/u/CedUE)\
**Post date:** [March 30, 2025, 7:56pm UTC](https://forums.unrealengine.com/t/fracturing-nanite-meshes/2420606/4 "2025-03-30T19:56:19Z")

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> The viewport just wasn’t reflecting the changes until the object was clicked on again (I guess clicking an object refreshes or reaquires its attributes?)

I’d expect the change to be applied immediately when pressing the tool Apply button  
But maybe there’s a bug, I’ll have to test on my end  
Are you using a geometry collection actor or is your geometry collection is in a blueprint ?

> I’ve tried to set the index at the moment of fracture, and in the fracture material editor, but it doesn’t seem to have any effect.

I had no issue in recent dev builds with this  
But I haven’t tried in 5.4.4. I don’t recall any change done in this area since 5.4 , so I’d expect to behave the same  
Does that happen when disabling Nanite ?

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**Author:** ![SpareHexGames](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@SpareHexGames](https://forums.unrealengine.com/u/SpareHexGames)\
**Post date:** [April 3, 2025, 1:56am UTC](https://forums.unrealengine.com/t/fracturing-nanite-meshes/2420606/5 "2025-04-03T01:56:14Z")

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For myself, in 5.4.4, I have been using geometry collections in the level. They aren’t a part of any blueprint.

When I turn Nanite off, everything runs perfectly- viewport updates real time, interior materials get assigned. I don’t have any problem with non-nanite meshes.

Thank you for giving this a look!

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**Author:** ![MostHost\_LA](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/mosthost_la/32/907035_2.png) [@MostHost\_LA](https://forums.unrealengine.com/u/MostHost_LA)\
**Post date:** [April 3, 2025, 2:43am UTC](https://forums.unrealengine.com/t/fracturing-nanite-meshes/2420606/6 "2025-04-03T02:43:34Z")

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Fwisw, i scripted my own GC (no not garbage collector) a few years back, since, i have never even bothered looking at the engine stuff.

Chaos is trash. Nanite much the same.

A custom built engine on PhysX will solve most of the real issues you get during development.

And also, it’s nicer to he able to have stuff you want happening with the geometry collections, like runtime based mesh fracturing via procedural slicing for instance, or just a pre-pachaged and highly manicured fracturing setup.

I don’t think the engine built in stuff offers any of that type of modularity. At least, it didn’t when I decided to make my own module…

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**Author:** ![CedUE](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/cedue/32/924243_2.png) [@CedUE](https://forums.unrealengine.com/u/CedUE)\
**Post date:** [April 4, 2025, 1:10am UTC](https://forums.unrealengine.com/t/fracturing-nanite-meshes/2420606/7 "2025-04-04T01:10:44Z")

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Hi

@SpareHexGames, I found and fixed a bug in the dev branch that that could effectively set all the materials to default on a Nanite geometry collection if one of them was not compatible with nanite (This will be included in the next release)

I’m not sure if that would fix the issue related to interior assignment though  
Do you have a video of the issue? that could help me better identify if there’s any step taken that could be missed / lead to the issue

Regarding the selection, I put also a fix that will show what pieces are selected in the 3D viewport when using Nanite ( this will also be included in the next release )

Thank you

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<div class="post-metadata">

**Author:** ![SpareHexGames](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@SpareHexGames](https://forums.unrealengine.com/u/SpareHexGames)\
**Post date:** [April 4, 2025, 3:37am UTC](https://forums.unrealengine.com/t/fracturing-nanite-meshes/2420606/8 "2025-04-04T03:37:46Z")

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I’m glad to hear that you found a bug! Hopefully it will help with the material assignments.

This account is a new user, so I don’t think that I can attach the video. It is a thirty second clip of me rotating the fractured mesh, and turning the nanite option on and off in the geometry collection asset. You can tell clearly when I switch it on/off because the interior faces lose their material, and the object rotations no longer update in real time in the viewport.

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**Author:** ![CedUE](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/cedue/32/924243_2.png) [@CedUE](https://forums.unrealengine.com/u/CedUE)\
**Post date:** [April 4, 2025, 11:20pm UTC](https://forums.unrealengine.com/t/fracturing-nanite-meshes/2420606/9 "2025-04-04T23:20:55Z")

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No problem

I think the rotation issue has been fixed in our dev branch , I’ll double check on my side

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**Author:** ![TetraStudiosDev](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@TetraStudiosDev](https://forums.unrealengine.com/u/TetraStudiosDev)\
**Post date:** [May 17, 2025, 11:16am UTC](https://forums.unrealengine.com/t/fracturing-nanite-meshes/2420606/11 "2025-05-17T11:16:59Z")

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Is Nanite required to render meshes with high amounts of fractures? I’m finding a building mesh that has 9k tris suddenly becomes 400k tris with 200 uniform fractures.

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**Author:** ![CedUE](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/cedue/32/924243_2.png) [@CedUE](https://forums.unrealengine.com/u/CedUE)\
**Post date:** [June 10, 2025, 4:06am UTC](https://forums.unrealengine.com/t/fracturing-nanite-meshes/2420606/12 "2025-06-10T04:06:39Z")

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Hi,

When you fracture, it is effectively easy to increase dramatically the number of triangles  
There’s two parameters that I recommend look at that may help you having a better control over that:

- Amplitude of the noise
- Point spacing  
When generating noise, the internal faces are subdivided and point spacing define how many vertices will be used to subdivide them  
If you noise is zero, then this will still collapse in quite simple large triangles, , however, if you have a non zero noise amplitude ,this may result in quite densely tessellated internal surfaces

When cutting large objects, it is recommended to increase the point spacing to a larger value

Nanite is not required but recommended if you start have very dense meshes  
Also nanite help with distance rendering as this will automatically adjust the level of detail based on distance from the camera

I hope this helps

Cedric
