Re: surface elements for transparent_solids.dem

[Daniel J S. <dan...@ie...>]

Anything wrong with the following approach?  As a prototype, I've moved the hidden3d line draw to after the pm3d is plotted in graph3d.c and changed the transparent_solids.dem command to:

set pm3d
splot x(u,v), y(u,v), z(u,v) with lines linecolor rgbcolor "black"

Remember, this is a prototype result.  The standard "set pm3d" version doesn't do depth sorting properly so you will see to the right that the colors don't properly follow the curve at middle height.

Some comments:

1) Ramifications for transparency I'm not considering now, just that tiling problem from the previous email.

2) Regarding the tiling problem, they are still there, but because the individual quadrangles weren't outlined these problems aren't too noticable.  The places where the depthorder sort fails happen for quadrangles that are pretty much the same value.  So, this isn't really a solution to the hidden surface issue, just a potential quick fix in some instances.

3) I do see some flecks here and there in the hidden line draw.  Perhaps a bug in the line draw (e.g., rounding/precision issues)?  Hans?

4) Also in the hidden line draw, note the difference between the attached PNG and the previous PNG.  There appear to be a couple lines missing from the Kuen surface on the left, pumpkin-colored surface where it curves inward vetically.

Dan