[bug] fix viewer crash after few seconds while streaming data from optitrack

[hoangminhtoan]

Fix bug when the viewer crashes after a few seconds while receiving FBX data from the Optitrack.

[YanjieZe]

Thank you for the pr. Would you mind simplifying the change a bit to handle this error? The motivation for this motion viewer is to simply visualization motion, assuming you have the right streaming data.

[hoangminhtoan]

Hi, Thanks for the feedback! I'll simplify the implementation to focus on the core error handling you mentioned. Let me refactor this to:
• Remove any unnecessary complexity I may have added
• Focus specifically on handling [the specific error - you'd mention what error they're referring to]
• Keep the motion viewer lightweight and true to its original purpose

The key changes I've made:

• Remove the threading (_lock, threading imports)
• Remove stability features (max_step_failures, viewer_timeout, _reinitialize_viewer)
• Keep only basic input validation in _validate_inputs()
• Keep the simple geometry bounds check in draw_frame()
• Remove most of the extensive try/catch blocks