The error threshold to use when optimizing and compressing the animations sequence. Lower values allow for less error, while higher values allow for less error. The ACL optimization algorithm will attempt to aggressively remove everything it can until the error exceeds a specified Error Threshold. For this reason, the threshold is very important and it should be very conservative. A default value of 0.01cm is appropriate for cinematographic quality and most likely does not require any tuning. The error threshold works in conjunction with the virtual vertex distance since the error is measured on the virtual vertices.