One of the requirements my collaboration Games group wanted was for the Robot to be able to interact with its environment on the gaming platform. The artist modelled two side arms on either side of the Robot’s head for this action to occur. When rigging the left arm, I had to rig the end ‘pincers’ to behave as a claw. I used Maya’s Node Editor for this mechanism to work and used the connection editor to connect the relevant joint to the control.
This shows the extreme open pose the claw can reach. The claw is also able to rotate around the claw centre pivot for added twist effect in the animation.
This shows the lower extreme that the claw can achieve, mainly used for grabbing and/or squeezing through a smaller hole in a panel.
The Game Designers also wanted the Robot to be able to retract the two side arms. With the left arm I treated it like a telescope and used set Driven Keys and a slider the control how much the arm compacts into each part. I set one key at zero with the arm fully extended and another at 10 with the arm compact.
Similarly, I used Set Driven Keys again to control the right arm’s compacting movement. This side arm is used to push buttons in the game environment and can rotate freely in any direction.