Hello, newbie here, so a probably very basic question.
I'm currently using the RBD DevTools, as shown in this tutorial https://vimeo.com/276130103/9fe71f678a [vimeo.com]
Right now I've had some great result creating dynamically destructible pilars in UE4 by exporting my fracturing animations as FBX skeletal meshs animations.

Now I'd like to have a pilar
that I can shoot at and see chunks exploding based on where I shoot at. To do this, I've done a basic RBD Fracture/RBD Director/RBD solver setup and I've played with the cluster options to place the fractures pieces exactly like I want them. My problem is that whatever I do, the gravity force in the RBD solver will always cause all my pieces to fall apart as soon as the animation start. What I want is to have all my pieces glueed together so that I can use specific force locations to blow off only the concerned pieces.

From all the tutorials I've seen, what I'm looking for is to setup glue constraints on my clusers, but this is done in a DOP network which I don't have as everything seems to be hidden inside the RBD solver object. I've try adding my own DOP network / Glue Constraint / Glue Adjacent stuff but I did not work as expected…



I hope that's clear, thanks a lot!

You can freeze everything in place by using another director node in front of the one that's doing the activating. Set the first Director node to Activate, but set the frame of activation to the last frame of the animation or higher. This essentially freezes everything in place, then you can use a second director node with shapes to activate the desired chunks. It will override the frozen chunks within those volumes and they'll activate at the specified frame.

Hi Sskar, thanks a lot, it works perfect and does what I was looking for. Now the only issue I have is that I can't get uv/normals on my fractured chunks… Do you know how I'm supposed to do that? So far I've tried the following:

In the SOP_RBD_Fracture node I've checked Interior->Generate Inside UVs. Then I've added a SOP_Visualize_UVs to check my results.

• If I connect the Collision Geo output from the fracture node to the visualize UV, I don't see any UV, from what I understand that's because I'm looking at packed primitives. Adding an unpack node before the visualize UV gives me uvs but only on the outside part of the mesh.
  
• If I connect the Render Geo output from the fracture node to the visualize UV, I see all my uvs as expected, but as soon as I reach an RBD_Director node with a Bounding object connected, the uvs are lost. It seems related to having a bounding object connected. Removing the bouding object brings back the uvs again…
  

Also as my goal is to export my animation as an fbx, what's the impact of using the Collision Geo output vs the Render Geo output from the fracture node… ?

Thanks a lot!