Box2D Forums

Ok guys, I've actually managed to create a character made out of "bones" aka rectangles that are all connected through joints that have set limits, the character standing still and it's all seen from a on-the-side perspective. Now, I've got a problem actually making it stand upright, whenever I start the simulation, he just bends his knees and falls backwards. I've tried a lot of things to bypass this, setting motor speed on the joints, setting angular velocity on the thighs and the calves, setting higher weight on the legs than the rest of the body, but nothing seems to work. Any ideas how to go around this? Thanks.

Does it fall when you have the revolute joints with enabled motors and zero motor speed? It should remain fairly rigid unless the upper body is heavy (absolute weight, not relative). The densities should all be small (like less than 10).

That didn't seem to work, he still bends his knees and falls backwards. Doesn't seem to matter how much density i set, I've tried a lot of values from 1.0 to 10.0 and it still does this. It's weird though, I could swear he didn't do that the first time I've run the simulation after setting all the joints.

As long as the center of mass is in a reasonable position and the max motor torque of the joints is high enough it should stay standing. The joint motor speeds are zero right?

Yeah, they are. I've tried playing around with max motor torque a bit, but all I've accomplished is that his legs become very stiff and take a lot of time to bend, but he still bends them eventually, so that didn't work either.