Mesh deforms after fracturing with CHAOS

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1

Hello, trying to set up the destructible mesh with CHAOS, but when I click on the mesh and select either form of fracturing (uniform, cluster etc) the mesh deforms after the fracturing. Any clues where I should look into for this?

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2

Bump, any ideas?
I literally just drop it in and use fracture.
Seems to work fine with other mesh, probably something mesh specific?

3

I thought of answering before but decided not to as I don’t know what it could be due to. I saw your post now again and think I can give you some generic help if you wish?

The issue of deformation after fracturing a mesh using CHAOS could be caused by a few different factors. Here are a few things you can check:

  • Make sure the mesh is properly UV unwrapped before fracturing it. If the UVs are not set up correctly, the mesh may become deformed after fracturing.
  • Check the settings in the CHAOS Fracture Component. There are several settings that can affect the shape of the fractured pieces, such as the “Voronoi Seed” and “Implode” settings. Experiment with different values to see if they affect the deformation.
  • Check the “Collision” settings in the CHAOS Physics Component. Make sure the “Collision Type” is set to “Use Complex Collision as Simple” or “Use Complex Collision as Complex”
  • Check if there are any deformers or other modifications affecting the mesh before the CHAOS component.
4

Hey there @Jim_Arabajoglou! Welcome back to the community! Since Chaos takes into account the normals on the mesh, could you do a quick check to make sure the mesh is water tight? If there are any unconnected edges or reversed normals, you can sometimes get these odd fractures. Are other fracture patterns also causing this deformation?

5

Hmm how could I check if it is water tight? Its a mesh of a house, and I think the roof material is “See through”
I’m also checking this document not sure if has to do with it
here

6

Thanks for the tips, tried most of them but no luck

7

“Watertight” just refers to the mesh not having any holes or if faces are reversed that face is treated like a hole, That is most easily checked in a 3D program like Blender. I’ll include 2 resources, one for conforming normals and one for general mesh cleanup (holes). If it’s neither of these, try a different fracture pattern, it could just be splitting verts at a really unlucky angle.

The material itself shouldn’t cause any distortion like that unless the material is using world person offset to a large degree and even then not like this.

Disclaimer: One or more of these links are unaffiliated with Epic Games. Epic Games is not liable for anything that may occur outside of this Unreal Engine domain. Please exercise your best judgment when following links outside of the forums.

https://docs.blender.org/manual/en/2.80/modeling/meshes/editing/cleanup.html

8

After trying some stuff as pointed out with no luck, I figured out I took the wrong approach on this (since there will be many dynamically generated instances of this) its not good for performance to have the whole mesh including roof fracture.
So used the modeling geometry split tool, and did the surrounding walls only, which seems to fracture normally. I believe the roof transparent material was causing this mess. Leaving this here.