# Break Geometry Collection, smallest pieces first?

I’m not sure if I am doing something wrong or if this just isn’t something Chaos is setup to do.

I would like to be able to break out the smaller pieces that the geometry collection is broken into and break out larger pieces based on the damage threshold.
Ex: A bullet hit causes a force of 25 with a radial field, this pushed out some smaller pieces, and multiple hits in a small area will keep knocking out small pieces.
A larger gun hits with a force of 100, so the holes it makes are larger, knocking out multiple pieces at once that the smaller bullet would knock out one at a time.

Does anyone know of a way to do this?

Did you find a way to solve this? I would be interested in knowing how to do the exact same thing. Thanks

I’m having the same case. I found a workaround that could work for you.
Generally it seems that cluster N+1 will not break until cluster N is broken, no matter the force. I set damageThreshold[0] = 500 000, damageThreshold[1] = 100 and hit it with a force of 200k. Nothing breaks.

So as a workaround I modified the clusters. Moved cluster level 1 to level 0 and level 0 to level 1. Then changed damage thresholds too ([0] = 100, [1] = 500k). As a result the smaller parts fell of first. This will not work in all cases, depending on what effect you want, it might not be doable.

To modify the clusters, select them and on the Fracture menu use ‘Level Up’ in the Cluster section. The option to reparent (cluster down) didn’t work for me. Instead I drag and dropped lower level onto higher level in the Fracture Hierarchy window.

Also note that it sems that the entire cluster gets broken if any part of it receives damage (Does Chaos have any concept of damage accumulation? or LoS/self-field blocking?) so it gets really hard to setup something different than ‘top down’ destruction.

Hi

Geometry collection have size specific properties to where you can set damage threshold per relative size

In 5.0, there’s some issues that prevent it to work as expected, but this has been addressed in 5.1
With it, you can then have various pieces under the same root cluster and have them to detach based on the force of the impact

5.1 also have many more improvements in how you can have better artistic control for how things break

In 5.0 you can play with the ClusterDistanceThreshold console variable:
It is 100 cm by default and by reducing it you can help minimizing the number of pieces that get released per cluster

Hope this helps

That’s got me confused. So If I set cluster threshold to 5000000 and size threshold to 10000 when will the piece of that size in that cluster detach?

There’s an option to opt-in for size specific damage threshold on the component itself ( just below the level damage threshold array ) , when doing so , level based damage threshold will be ignored and only size specific rules will apply
However as stated earlier 5.0 has a bug that does not assign the size specific data properly in all cases, but this has been fixed for the 5.1 release