In article <MPG.16e362bd507e6d0b9896e1@news.povray.org>,
 Lutz-Peter Hooge <lpv### [at] gmxde> wrote:

> Why not make it dependent on the distance between the previous and the 
> next control point? 

Better would be to make it dependant on the distance along the 
spline...try an epsilon value and get the distance of the point from the 
current point, if it is too small increase it.
But for this application, it isn't very critical...just use a large 
enough sample to make errors extremely unlikely.


> Has the mesh-approach any advantage over using bicubic patches? The 
> documentation says bicubic patches are converted to a mesh internally, so 
> speed should be equal (but I didn't try yet), but parsing should be 
> faster with patches.

Not really. Patches are converted to triangles for intersection testing, 
but they can do adaptive subdivision on the fly, which slows rendering 
but uses less memory and parse time. It is harder to connect them 
smoothly, as well.
And a single mesh will have an advantage over a bunch of patches...a 
mesh can be very efficient about which triangles it tests, and can use 
tricks a union of patches can't. So a mesh will probably render faster.
Then you have the advantage that copies of meshes use very little extra 
memory...

-- 
Christopher James Huff <chr### [at] maccom>
POV-Ray TAG e-mail: chr### [at] tagpovrayorg
TAG web site: http://tag.povray.org/

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