wrote:
> 
> If the items uniformly disappeared I would think it was a
> floating overflow or something, however only certain items
> seem to disappear, and not necessarily the furthest.
> 
> On my machine the system seems to have about 17 digits
> of precision for floats as I am only using 9 this should not be
> an issue (I determined this by doubling a float in a loop and
> printing the results and marking where the least significant
> digit started to become in error):
> 

Floating point error analysis is a bit more complicated than you seem to 
think. For intersections calculations a ray-tracer needs to do a sequence 
of calculations and the error which is produced by the limitation of 
floating point precision is propagted. As there are different calculations 
done for each primitives it is natural that the floating point error 
effects are also different for each primitive. In short: What you are 
seeing is definitely an effect of FP precision.

- Micha

-- 
objects.povworld.org - The POV-Ray Objects Collection
book.povworld.org    - The POV-Ray Book Project

Post a reply to this message