Rich asked:
Why not just set the user float flag? Why set bit 2?
Is there some condition where you *don't* want to use floating-point but *do* want to use floating-point for lines?
It just feels redundant to set bit 2, particularly since all the other tests in this file just test if user float flag is non-zero or zero.
Jonathan's comments on this looked accurate. After making the disclaimer that it is always dangerous to change behavior because you never know when some fractal artist is using artifacts of integer math - here is my opinion: As the original author of the 3D transformation (ah, those were the days, designed and coded it from first principles without the benefit of either knowledge or experience), I don't see the point (any more) of using integer math for the 3D transformation. The use of math library to generate the original fractal is conceptually separate from the use of math to generate the 3D transformation. Speed is no longer an issue - so my suggestion would be always use floating point math for the 3D transformation. I should think one would want any fractal converted to 3D as accurately as possible, no matter what the origin of the fractal. The 3D feature is pretty primitive compared to generating the 3D using the fractal as a height field in POVRay. There is no hidden surface algorithm other than calculating the image back to front. Tim