Tweaking the Prop Disc in 940

X-Plane 940 allows plugins to customize the prop disc. Details here on the wiki.

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.

In short, prop discs are weirdly special-cased enough that I thought it would be better to provide a general set of parameter datarefs for prop discs and let X-Plane do the drawing.

These options are not available in Plane-Maker. Why not? That'll be my next post.