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Shape_Plane versus Plane and collisions

I am in the process of learning Unreal and have been building small little things to better learn how the engine works. I noticed something strange in one of my projects where falling cubes where colliding strange ways with planes (floor), eventually going through the plane.

After some experimentation, I believe I isolated the problem.

If I drag and drop a Basic Plane into the level, place a Basic cube above it, turn “Simulate Physics” on for the cube and Play, the cube will fall onto the plane and stop. Which is what I would expect.

If I create a new Basic Plane and then change the Static Mesh to Shape_Plane, place a Basic cube above it, turn “Simulate Physics” on for the cube and Play, the cube will land, have some rotation, and work its way through the plane. I included a screenshot. The right is the plane using Shape_Plane.

I also have found that if I change the Static Mesh to a Shape_Plane in Details, I cannot change it back to Plane.

I’ve noticed the difference is that Plane is it points to /Engine/BasicShapes/Plane and Shape_Plane points to /Game/StarterContent/Shapes/Shape_Plane.

This leads to my questions.

  • Is there are reason why setting Shape_Plane as the static mesh has this behavior? Should I not be explicitly setting the static mesh like I did?
  • Is there a way to get the Shape_Plane static mesh to have proper collision? Or maybe phrased differently, to get it so objects collide with it properly?
  • Is there a way to set the Static Mesh to Plance (/Engine/BasicShapes/Plane)?

I have built something that is using a Shape_Plane mesh. I suspect why it is that is it may have been another shape like a Cube to start, but then I changed it to a Plane when I decided it would be the floor.