* <code>model_rotation</code> Props placement rotation.
'''How does it work?'''
Props is rendered and placed as separate model. Using bone A and bone B we can attach the props to the mover skeleton. There are three possible setups.
;: '''1) No bones are set.'''::Props is placed to te the mover origin plus <code>model_offset</code> and with zero rotation plus <code>model_rotation</code>.: '''2) Bone A is set only.'''::Props is placed to the bone A placement plus <code>bone_offset_a</code> plus <code>model_offset</code> with bone A rotation plus <code>model_rotation</code>.: '''3) Bone A and bone B are set.'''::Props is placed to the bone A placement plus <code>bone_offset_a</code> plus <code>model_offset</code> with rotation given by direction vector from bone B placement plus <code>bone_offset_b</code> to bone A placement plus <code>bone_offset_a</code> plus <code>model_rotation</code>