Would it be possible to detect if a force is currently applied to a Rigidbody? And if that would be possible, is it also possible to access the amount of force that's still being applied to it?
You could do this by examining the change in velocity each FixedUpdate. Simply create a Vector3 variable to store the previous velocity value, and subtract it from the current velocity to find the change each frame.
If no force is being applied, the velocity should remain constant. The change in velocity, divided by the object's mass, should give you the sum of all the forces being applied, including gravity and any drag values which have been specified.
I also have this problem and the solution here works to some extent but not totally.
In my project, I need to know the normal force between the tire and the ground. I can use previous velocity to get some idea but the normal force is also affected by the way the vehicle is tilted and moving and how the ConfigurableJoints between the tires and the vehicle body is aligned at the moment.
I will try to make some workaround for this but it would have been GREAT to get this directly from the physical engine (which has to know this to make the calculations).
/Ricky