I’m experiencing the following strange behavior wrt to collisions in 3d. I’m not sure it’s a bug. Sharing it in case anyone it rings any bells:
I have a test project with a long base co object and two smaller co bodies placed upon it at a small distance. No sprites attached to the gameobjects. Only collision objects. I’m running the project in ‘Debug’ and watching the outlines to observe how it goes. I’m pressing M to trigger throwing the first object onto the second. I do it by setting the linear_velocity of the first so that it slides on the base and hits the second. I switch from between 2D-3D to play with both physics back-ends.
The strange stuff
In 3D mode only, if i wait for a second or two before throwing the object, it just won’t move at all. Acts as if it rooted on the base. If i throw it right away it works as expected. Box2D also works as expected in all cases, delayed or not.
A potential hint
I recall a use case where i had a collision object placed over another (static one) supporting it. I continuously printed the position of the first. It was placed at (5,5,0) but what i printed was not exactly that but differed by a very very small value that kept changing for some iterations. After some time - no more than a second - it settled to (5,5,0) indeed.
Can’t say if this is related indeed. It introduces though the notion of delay in the behavior i got.
thoughts ?
UPDATE:
test5.zip (3.2 KB)
The project above illustrates the bug. It’s a falling object to a base instead of two sliding objects. You can still see that once the falling objects settles on the base it can’t move, whereas while falling, it can (3d mode).
Note, In 3d mode, the debug drawn objects appear as tiny pixels. Check at the bottom left side of the window.