<Jer### [at] enstfr> wrote:

> Yes, that's it. I think that "normal off" is less accurate precisely 
> because it relies on a sampling method. OTOH it works in all cases 
> whereas "normal on" requires more definitions (in POV's source code, 
> not in your file) that don't exist for all functions (and maybe can't 
> exist for some) and therefore is less general.

But what about the speed? "normal on" is slightly *slower* than the 
original method...and I don't think tracing 3 jittered isosurface rays 
would be very fast.
I had the impression the original method used several (7?) samples of 
the function to determine the normal(sort of like the way MegaPOV 
calculates the normals for patterns, and the way my displace warp 
works). Sampling the *difference in density* in each direction from the 
point, which is much faster than tracing rays.
I could be completely wrong though...I haven't even looked at this code.

-- 
Christopher James Huff
Personal: chr### [at] maccom, http://homepage.mac.com/chrishuff/
TAG: chr### [at] tagpovrayorg, http://tag.povray.org/

<><

Post a reply to this message