Breakable glass mesh. Need help with Houdini


Is anyone can help me with making breakable glass mesh. Main idea to make breakable glass like in the Control game by Remedy.
I need a box divided by voronoi to small tiles. Each tile has caped polygons from all sides and back.

Unfortantly i have no Houdini license, but pretty sure that is easy and fast with Houdini.

What actually i need.

  1. 10 meter x 10 meter x 0.01 meter Box dimension (1000 x 1000 x 1 Unreal Engine / max / maya units)
  2. Divide box with Voronoi to the random tiles with random radius 15-30 centimeters with caped side and back polygons
  3. Export to the FBX format.

See picture for detailed explanation. Hope someone help me!

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Done. With Blender:

Finised tool (UE4, cpp). Fully automatic:

  • Corner detection for any appropriate geometry surface. Glass tile(s) wont drop down while connected with at least one corner tile.

  • Store corner tiles ids.

  • Calculate neighbors link tree for each galss tile.

  • Calculate OBB of tiles for proper scaling debris particles.

  • Create and save DataAsset for UE4.

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Python script for Blender.
Divide glass surface to tiles, create bones and bind each bone to the appropriate tile.
Rectangle, ring and cylindrical glass shapes are supported by default.

Most important script’s code is finished.

One Button glass generator =)


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I see a lot of polygons in your mesh, that you dont need and will hit performance.
what we did was small voronoi fractures then make clusters to get the shape you say (green line)
then preserving the edges we made a clean low poly mesh, and then extruded back to the original glass size.
the small cracks is just a texture dont even match with the corners most of the time.
hope it helps


You can adjust how many polygons need, just decrease subdivision factor. Yeah, small cracks it’s texture. For modern GPU, many polygons is not heavy task. Optimization can be made by hand, but my research tell me about minus 15-20% from initial polygons count. Seems not so effectively for hand made task vs required time. Also optimized mesh need to be UV remapped.

Extruded by contour is good for flat glass, but does not works for bent (cylindrical, car, arc) glass.

On final stage. Core logic and toolset finised. Supported all glass shapes except spherical and with internal holes.
Glass code is 100% blueprint.
Toolchain: Python script for Blender and C++ Project for UE4.


Looks good! How well does it perform?

Thanks! Currently testing with different surface shapes - squared, arc, cylindrical, etc… implementing particle system and glass material. Works well, performance not tested yet, but with 55 tiles on first look here is no any fps impact.

Glass blueprint can be nativized with UE nativization tool or rewritten to native C++ code. Is not too complex code inside.

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Cracks texture finished. 4k x 4k size. Generated inside Blender with voronoi shader node. 4 hours of hand work to creating seamless texture…ohmg… feels like monkey worker ))

Almost finished. Need additional praticles tweaking and some sfx.