Physx + destructibles (Tim Hobson plz help)

Trying to create a “floor collapse” sequence. I’ve been using a destructible mesh (created using UE4) to produce the following effect : Collapse_test.mp4 - Google Drive

I’m using a series of target points along the mesh, along with timed “Apply Radius Damage” functions in BP to break up the mesh. Also placing a couple of Blocking Volumes below the DM, destroying them in a timed way to get the chunks to ‘depress’ in a stylized way. Finally removing the blocking volume so the entire mesh can collapse and fall.

However. I would like more control over the DM. For example, the effect i’m looking for does not necessitate the entire mesh to be destructible. Right now, using UE4, I can set the Cell Site to 750, but I feel like this isn’t efficient, and if I could fracture the mesh myself, I could lower this. Furthermore, I would like to have “layers” of depths to the mesh, so that the surface layer breaks up into smaller chunks, and that with higher destruction values, lower layers break up into more foundational (large) chunks.

I was referred to PhysX Lab. Problem i’m having is the documentation on PhysX Lab is a bit limited… the tutorials, i’m following. But i’m running into some issues. First of all, after I use a fracture map and fracture it (with 100 thickness to cut all the way through), I get this : physx_issue.mp4 - Google Drive

It’s like it creates the fracture depth, but still has the original mesh in it or something. I’ve tried this with different meshes, and even with the Wall mesh provided by Nvidia for the tutorials.

Secondly, I can’t seem to figure out how to both use a fracture map, AND determine multiple destructible depths. Should I just have 2 separate destructible meshes then? With different fracture maps? And then just Damage them in UE4 in such a way as to replicate a mutliple depth DM?

thanks, long read I know.