Camera breaks through wall but only in 1 direction

Bugs
, ,
1

Placing a wall with MeshBuilder.CreateBox() about 20m behind my camera.
We constrain ArcRotateCamera rotation to 90deg either side, so the camera cannot rotate to see the wall.

Then I rotate left or right to that 90deg limit.
Then I start panning sideways towards the wall.
The camera will pass right through the wall, despite wall.checkCollisions=true and camera.checkCollisions=true.
Once through though, the camera will NOT pass back through the wall. Collisions now behave as expected. It’s a one-way bug.

Camera has a reasonable collisionRadius which works fine against all the loaded walls. It just gets weird with the dynamically-generated wall.

Curious, I tried applying wall.rotate( Math.PI ) to see if the bad behavior flipped if the wall were flipped, but no change.

Baffled. What’s going on?

2

Rotate the camera either +90 or -90deg, hitting the rotation limit.
Pan the camera towards the wall.

Camera will break through the wall, but then collides with wall if you try to return.

3

I notiiced that you rotate wall meshes.
I believe the problem is related to normals direction.
Try to rotate the problem mesh 180 degrees.

4

The 180deg wall mesh rotation changes nothing about the behavior Im afraid. Sorry, left that in there by mistake as a test of the very idea you’re considering.

5

https://playground.babylonjs.com/#G63U4T#2 This breaks collisions both ways. Seems like it has sth to do with alphaLimit. Not setting alphaLimit but setting alpha itself to 0 does not break collisions.

Collisions are triggered though https://playground.babylonjs.com/#G63U4T#3