Chris Huff wrote in message ...
>In article <3a1e6b2a@news.povray.org>, "Wlodzimierz ABX Skiba"
><abx### [at] abxartpl> wrote:
>
> > first I prepare CSG than I declare function{pigment{object{...}}} to
> > describe interior of it and then I clone this as isosurface.
> > Isosurface has artifacts even with accuracy 0.00005.
> > I have calculated value (with eval) of max_gradient as 200000 but
this
> > not help.
>
> The object pattern has two states: on and off. It doesn't have any
> "in-between" values. Patterns like this have an infinite gradient, and
> cause the isosurface algorithm problems. Other patterns that have this
> problem are checkers, hexagon, brick, and any pigment that has sharp
> lines.

I know this but unfortunatly in current (unoficial) state of pov this is
only way to play with described week ago nonlinear transformations.
Everything is ok but normals.

hmmm

perhaps the problem can be resolved just like in smooth_triangle ?

in 2D description:

1. take point at equipotential surface
    P
2. take value at corners of cube around of it (size of cube depends of
accuracy)
   V1---V2
    |\ /|
    | P |
    |/ \|
   V3---V4
3. find points on edges where value is like in P
4. aproximate normal

ABX at babilon at org

Post a reply to this message