Some issues in collision resolving.

Hi!

Characters in my game presented in physics world as a Ball, I call rigidbody.set_linear_velocity() every frame, to control them. And sometimes characters can pass between 2 cuboid walls like this:


For example, there is 2 cuboids, on (-0.5, 0) and (0.5, 0), timestep 1/10 and ball with radius 0.3 on position (0.0, 1.2), setting it linear velocity after every step to (0, -5.0):

Ball: Translation { vector: Matrix { data: [0.0, 1.2] } }
Ball: Translation { vector: Matrix { data: [0.0, 0.70000005] } } // Collision happens on next frame
Ball: Translation { vector: Matrix { data: [0.0, 0.95000005] } } // Collision happens and resolved
Ball: Translation { vector: Matrix { data: [0.0, 0.45000005] } } // Going through cuboids
Ball: Translation { vector: Matrix { data: [0.0, -0.049999952] } } // Going through cuboids
Ball: Translation { vector: Matrix { data: [0.0, -0.54999995] } } // Going through cuboids
Ball: Translation { vector: Matrix { data: [0.0, -1.05] } } // Finally passing through
Ball: Translation { vector: Matrix { data: [0.0, -1.55] } }

If i change a start position of a ball slightly to (0.0, 1.3) - it can't pass through:

Ball: Translation { vector: Matrix { data: [0.0, 1.3] } }
Ball: Translation { vector: Matrix { data: [0.0, 0.79999995] } }
Ball: Translation { vector: Matrix { data: [0.0, 1.05] } }
Ball: Translation { vector: Matrix { data: [0.0, 0.54999995] } }
Ball: Translation { vector: Matrix { data: [0.0, 0.81401926] } }
Ball: Translation { vector: Matrix { data: [0.0, 1.0640192] } }

Also, if move it a little right to (0.01, 1.2) and *increase* speed to 5.01, ball can't pass too.

I understand that behavior depends on timestep and speed, but it looks like that position can be correctly resolved on this steps of first example:
Ball: Translation { vector: Matrix { data: [0.0, 0.95000005] } } // Resolved
Ball: Translation { vector: Matrix { data: [0.0, 0.45000005] } } // Going through cuboids
Ball: Translation { vector: Matrix { data: [0.0, -0.049999952] } } // Going through cuboids

And in the game, this things can happens on low velocities.
I'm playing with integration parameters (and setting ERP *iterations to max values), and nothing helps.

UPD:

Also, I iterate through all contact events during every frame, and there is a really strange things:
Cuboid(0) - 1.0x1.0 static Cuboid placed on -0.5, 0
Cuboid(1) - 1.0x1.0 static Cuboid placed on 0.5 0
Ball(2) - Ball with radius(0.3) placed on 0.0, 1.2
Default integration parameters, without gravity, timestep - 0.1
Every frame after step linear velocity setted to (0.0, -0.5) on the ball rigidbody

Frame 0- Ball: [0.0, 1.2]
Frame 1- Ball: [0.0, 0.70000005]
Frame 2- Ball: [0.0, 0.95000005] // Collision happens during this frame and have been resolved, but contacts only started and not stopped
Contact between Ball(2) and Cuboid(0): Started
Contact between Ball(2) and Cuboid(1): Started
Frame 3- Ball: [0.0, 0.45000005] // Shapes intersected, but contacts stopped (they must be stopped in previous frame) and not started (?)
Contact between Ball(2) and Cuboid(0): Stopped
Contact between Ball(2) and Cuboid(1): Stopped
Frame 4- Ball: [0.0, -0.049999952] // We are still in collision, but there is no started contacts
Frame 5- Ball: [0.0, -0.54999995] // And we are still in collision
Frame 6- Ball: [0.0, -1.05] // Our ball passing through cuboids and away from them, contacts started just now
Contact between Ball(2) and Cuboid(0): Started
Contact between Ball(2) and Cuboid(1): Started
Frame 7- Ball: [0.0, -1.55]
Contact between Ball(2) and Cuboid(0): Stopped
Contact between Ball(2) and Cuboid(1): Stopped