Making a catapult vehicle with physics.


I have a question related to the physics engine.
I’d like to make a catapult that consists of two objects.
The first object is the base of the catapult, and the second is the actual thing that swings the projectile away. The base should be able to move around on the ground.

How can I achieve this? I tried parenting the swing to the base, but when I do that, the child isn’t able to collide with anything.

I want it to work with physics and not with IPO-animation, because then I can use the same technique with other things too. (Actually, an IPO-solution is fine too. All I need is that the swinging part interacts with physics collisions.)

Has anyone done anything similar?

Can you post a blend file? That would likely make this easier to see what’s going wrong.

Ok, so basically I want to attach the swinging part to the catapult base.
I don’t know how to do the attaching part while still having the swing to react to game physics.
There’s the .blend-file.
Arrow keys control the platform.


game_catapult.blend (188 KB)

You should investigate using physical joints. You know the Object constraints? There’s a type called “Ridgidbody Joint”.

I’ll let you discover the rest. :confused:

Got it! Thanks.
I somehow thought that all the game physics stuff would be contained in the logic buttons.