I put these datarefs in so that modelers wouldn't have to try to model prop discs with OBJs. The problems with prop discs are many:
- They need to be billboarded, and X-Plane does not provide datarefs for manual billboarding inside an airplane (particularly not to the engine's coordinate system, which can be transformed by all sorts of fun stuff).
- They often need variable translucency, which OBJ does not have.
- They cause all sorts of depth buffer errors, which OBJs cannot manage.
These options are not available in Plane-Maker. Why not? That'll be my next post.