rigid body on windscreen of a car

Question

I have a jeep, and I want the windscreen of the jeep to bounce up and down because of the movement of the car between these two positions by using rigid body physics:

I tried using the hinge rigid body constraint, which works perfectly fine to let the windscreen drop down by gravity, but when I try to move the jeep the windscreen doesn't come with it, like it isn't parented anymore. When I select animated in the rigid body physics tab, the windscreen moves with the jeep, but the rigid body physics don't work.

How can I set up the rigid body physics so that the windscreen bounces up and down, but is still parented to the car?

Answer 1

It could work in a way like this (see the example .blend in the linked zip file below):

1. add an empty with the Z (mandatory!) axis along the axis of rotation you expect for the windscreen
2. add a (physics) "rigid body" passive setting for the body of the car (or whatever should "hold" the windscreen), set it to "animated"
3. add a (physics) "rigid body" active setting for the windscreen
4. set a (physics) "rigid body constraint" setting for the empty and set the windscreen as object 1 and the "body" (or whatever) as object 2
5. set Z axis limits for this constraint ( I used -5°/+80°)
6. select windscreen, then the "body" (or whatever) and CTRL-P to parent the them. Do the same with the empty.

now, if the car is animated and then stops, the windscreen behaves similarly to what you expect. You may have to adjust settings, damping, friction, etc.

to see my example, open the .blend in this .zip, and press ALT-A to start the animation: http://amrc.altervista.org/wp-content/uploads/2015/10/rigid.blend_.zip