Circular conveyor belt simulation

[hazidh]

Hello Sir, I found that when I use these two lines of code to make the Box move in a circle, its rotation attitude around the center will change. For example, the Angle from the center is 0 at the beginning, but it will have a certain Angle around the center, such as the picture.May I ask why？

 float speed = angularSpeed * contactToCenter.length();
 PxVec3 velocity = tangentDirection*speed;
 contacts.setTargetVelocity(j, velocity);