Fix minor bug introduced in 01d8c708b21d25ead
Makes the selection of Morsy color more robust with several instance

The manterial name change to 'body.001', etc. for each new copy of the robot.
By relying on the index, we avoid this issue.
Do not crash when using cameras in fastmode

Instead, display a gentle warning.

While here, slightly improve performances of camera by skipping useless test once the
camera is setup.