With my current settings, objects easily pass through each other when they come into forceful contact. This video shows the green and red blocks falling through the surface of the table when struck by the robot end-effector: Is there a way to change the model settings to prevent this? I've attached my xml file. Thanks, Emo.
Playing around with the simulator and reviewing the documentation, I figured out that there are basically no hard constraints in MuJoCo. If you push hard enough on something, you will go through it. To resolve this issue, I simply applied force limits to the actuator: Code: <motor gear="1000.0" name="arm_flex_motor" joint="arm_flex_joint" forcelimited="true" forcerange="-.2 .2"/>