get total forces/torque on a given .obj

[physics_boii]

Is there any easy of way of getting total torque/forces on an object?

I imported two .obj into the environment on a plane and am able to use getContactPoints() that have the normal forces and each contact force, but really need torque/total forces on a given object. Do I need to calculate this* and sum them up to get them, or is there some existing function that already does this? It would be like having a torque sensor at the center of gravity of the object. (this object also has forces acting upon it, just to be clear)

*(getting torque by using distance of forces is from center of gravity of the object and summing them, and also getting forces from this).

Any advice would be much appreciated!

[elod.pall]

I'm also interested in attache a virtual FT sensor to an object. Now, I'm doing as @physics_boii described it, summing up forces (but I'm not computing the torque yet).

By the way, how is the contact forces computed for face-edge, face-face, or edge-edge contact?
1) I've seen that edge-face contact produces two contact points at the end of the line segment where the two objects are in contact
2) face-face contact points for a cube and plain are created on the corners (which touch the surface) of the cube.