Set damage amount for slow moving rigid body

Omniverse Developer Tools & Resources Samples & Examples
1

Hi,
I have a slow moving rigid body but want to apply a great amount of damage to a fractured mesh. How can I set this? I increased the mass and density but doesn’t seem to help, it just briefly shattered the mesh, how can I make it explode? I can only do this from the debug damage tool

2

Hi qazs,

The debug damage tool simply performs a scene query around the damage point and applies an impulse to all rigid bodies it finds. You can do the same of course, but perhaps that’s not a very satisfying answer.

I can tell you, however, that a new version of the omni.blast extension will be available soon (shooting for this summer), which has a greatly reworked damage system. We’re incorporating a stress solver that replaces the action of blast damage shaders, allowing impulses (due to impact, or user-provided) to propagate in a more physically realistic manner. In addition, there is an option to always run the stress solver on a blast instance. This adds more realism, as things like weak overhangs will naturally break off on their own due to internal stresses.

I bring this up because is actually relevant to your question - with the new stress system, pieces break apart due to bonds being unable to compensate for the forces on joined pieces. The excess forces (the component that exceeded the bond’s strength) are applied to the broken pieces. We provide a multiplier (default value 1) which you can set for those forces, to adjust the response to damage. This will hopefully give you the knob you need for your use case.

Bryan

3

Thanks, looking forward to the new version and if possible please do a tutorial as well.
Also I’ve a suggestion, is it possible to customize the blasted pieces shapes, for eg. cubes and spheres? If it’s blasting a glass object it looks fine with the shards, but if it’s a brick wall it looks quite weird. Anyway it’s already an amazing feature.

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@qazs we have plans to add support for other fracture patterns. Some things, like wood, can be achieved by stretching things before/after fracture. But we understand the Voronoi fracture does not cover everything.

For brick specifically, one thing to try (that we did in a demo) is to model an individual brick and the mortar around it. Duplicate that to build the wall. You can either fracture it first to have a single base, or after combining them if you wan them to each have a unique fracture pattern. That way you can better control bricks staying whole and leaving better outlines when you blow a hole in the middle of the wall.