Animation with physics, UV sphere can't fall through the ''empty' I've got the problem while creating animation with physics in Blender. So I have two spheres and a tank. The aim is to get both spheres come through this tank.

1) Yellow sphere animation is based on physics (both sphere and tank are set as rigid bodies), BUT it can't fall into the tank, like there is no empty in there. 

2) Red sphere animation was made as simple keyframe animation, it works pretty well but it not realistic, so method with physics is preferable.

Maybe someone had this poblem and could help me to solve it.
Thanks!
Thanks cegaton The solution is to set "mesh" as the shape in the rigid body collisions setting.