I’m doing some experiments with Blender physics and cell fracture.
Basically, I wanted to animate dropping on object on a floor, and the floor fractures into pieces.
I created the following:
A fractured floor with Active Rigid body.
On the bottom a simple plane floor with Passive Rigid body.
As long as nothing hits the fractured floor, everything should stay where it is, laying on the plane.
However, there are always some pieces that still fall partly through the floor. These pieces pivot through the passive plane floor. See also the picture and Blend file.
I can prevent this by using the “Enable Deactivation” and “Start Deactivated” options on all the pieces. But as soon as something hits them, they (of course) get active and therefore pivot through the plane floor again.
I also explored the option of manually changing the origin point of each of the pieces that form a problem. This only helps a little, as they are still “unstable” and have the tendency to pivot through the passive plane floor.
I’m guessing Blender has problems when two active objects are too close to each other.
I think I found a solution, although not a perfect one.
Scaling the fractured meshes up or down and then applying the scale can help. With my example file both worked.
Various scales have different results. When I don’t scale up or down enough, some of the pieces may still fall through the floor.
I also tried more fractures with the cell fracture tool. It would seem the more individual pieces I have, the more difficult it is to get it under control.
ensure your physics settings are high… try 240 iteration and 240 steps (rigid body section of the world tab)… this will make ALL of the rigid body setup more accurate…
it will also take longer to process…
Also make sure all of the shattered pieces are the correct collision type… (preferably convex hull… but ONLY if the meshes ARE convex… otherwise use mesh type collision object.)
also for the floor, try using a box instead of a plane… (give it the box collider type) this could help keep objects “above” the floor…
