Destruction is one aspect that I really like the most in FX. In this small article I am going to explain how chaos physic works inside Unreal, its a bit easier for you . if you have dynamic background such as Houdini. Epic claims this would be future physic of this engine.
A. Chaos Physics
the way it works is simple, you do voronoi fracture in multiple times. and each level of that would have their own constraint. so basically if the first level is broken, you can break the next. You can do this as many times as you want. But for me 2 - 3 is good enough.
1. Preparing Assets
I really need to make sure that the model would be destructible asset, and absolutely has volume or manifold geometry. otherwise the destruction will look bad.
2. Chaos TAB
This is the implied version in Unreal Engine 5. so you just need to go this tab and all of the sudden all the chaos features are here. Or you can call it active fracture editing mode.
B. Adding Forces.
Adding forces to destroy your chaos is not easy as Houdini. You need longer step to achieve this. You literally need actor blueprint for this.
The sad part it takes few minutes to set anchor in Houdini. Inside unreal creating anchor field can take a lot longer than that.
C. Secondary Elements (Debris and Smokes )
Now that we know how to destruct things in Unreal, Lets add secondary elements, such as debris particles and smoke sprite to make destruction richer.
All of this can be done using Niagara. You just need to put Niagara listener module to the system. If you want to customize just used a scratch pad module. No need to worry, scrath pad is just like attribute VOP in the nutshell.
Chaos is very good, I think to improve the performance you need to enable auto deactivation thing when the velocity reach certain threshold. just like bullet sleeping in Houdini. You really need to use C++ to make run properly in realtime.
At the end of day I realize that this chaos workflow seems work well too inside Houdini lol.