physics - shape of object

is it possible to make functional a specific shape to physics behavior? i mean i have a ball and when it reacts with other objects i want it to react as a sphere, not as a box. how can i do that?

Yup, just set a custom collision mask in the Physics behaviour properties and then edit the mask. You can draw an outline of your shape then.

For spheres, just choose the collision mask of "Elipse"

fantastic! thanks much :)

But always be careful when setting up your own mask. The physic object is fastest with sphere, fast with box and slow to really slow with custom shapes, dependent on the count of points your shape uses. The more the slower.