I’m trying to set up an actor that has one destructible object that is attached to a none destructible object. For example. a sign on a sign post, where the sign can be smashed up into pieces but the post cannot. I want to use Unreal’s Chaos fragmentation system but geometry collections are free floating so they just fall to the ground from where ever you spawn them in.
I understand that you can use anchor fields to set certain fragments to be static and that is great, but I want to avoid manually setting up an anchor for every sign in my game. I have tried a few things with no luck so far:
I set a geo collection and anchor field as components of my actor, and set the initialization field of the geo collection both in the constructor, and begin play.
I tried using “Set anchored by box” node on the geo collection in begin play with the same setup as above.
I tried spawning in an FS_Anchor_Field_Generic actor at a desired transform and set the initialization field of geo collection in begin play.
None of the above have worked so far The geometry collection is still not getting anchored, and I’m not sure why.
How would you guys make an object like this with a very distinct breakable and non breakable parts, without creating a separate anchor actor for each one?
You can do it in many ways, however the easiest approach is probably to manually fracture / cluster it.
In the Fracture tools menu, there should be Mesh Cut. You can cut your mesh, then on Level 2 or higher fracture it more with Cluster or similar tools. You can give different damage thresholds to different levels/clusters, and keep the parts you do not want to crumble with a very high threshold, or anchor the root/support part.
Alternatively, you can just divide the post and the sign into two separate mesh objects. Keep the post as a normal non-destructible Static Mesh, and make only the second mesh/sign breakable/destructible as a Geometry Collection.
Cool, I didn’t think you could manually fracture the mesh, that could be useful but that doesn’t solve my issue. Weather the sign post is one mesh or two does not mater, I want to be able to anchor the post to the ground without using a separate anchor field actor object to do so.
In a way I’m trying to make this object spawnable.
I’ve been trying to combine a geometry collection and an anchor together into one blueprint which I think is possible but nothing I have tried has worked so far.
You can anchor any part of the mesh directly in the Chaos fracture hierarchy.
In Fracture Mode, select the bones / clusters / hierarchy parts that you want to stay fixed, then set those as anchored / static support parts. So for a sign post setup, you can keep the post/root/support fragments anchored and let only the sign fragments break.
This way the object can still be spawnable as one Geometry Collection / Blueprint, and you do not need to place a separate anchor field actor for every instance.
You can also anchor the bone if you click bones, you will see you can set static, or anchored. Also that should be doable from data flow graph too, however you can simply bind objects by a component or union cluster.