www.algodoo.com

but since this is scene sharing, this scene https://www.mediafire.com/?q1qm0ldy51fq477 i'm trying to make that purple truck a transformer, and i know exactly how to do it but for some reason objects keep going through other objects and they ignore their set collision layers. like when put on a one-key toggle motor or brake, you can see in the scene, press f for the cab to open, and the pink block, the mechanism on top i'm trying to make, you notice how the 2 triangles keep going through the other objects regardless of the collision layers :/ (press G if you dont know what im talking about)

No, it is not a bug. The reason the triangle go through the little red block is that the torque of the motor is too strong, lower the torque(10Nm will solved for your case), larger the red block or increase the density of the red block might solve the problem.