Re: pm3d question

[Hans-Bernhard B. <br...@ph...>]

Ethan A Merritt wrote:
> OK. Yes, I see the same difference in speed with isosamples set to 40.  
> Although you can get a factor of roughly 4X back again by enabling 
> HIDDEN3D_QUADTREE.

At high isosamples settings, you should absolutely use that switch.
I've even been thinking about enabling it by default.

> This will not magically do the full, correct, tests for
> which quadrangles to clip. But it *will* mean that other objects
> (labels, points, vectors) will be correctly obscured by the 
> Z-sorted quadrangles, and vice versa. 

I'm reasonably sure it doesn't mean just that.  It actually means means 
that all the problems inherent in treating polygons as sortable points 
will be inflicted on the hidden3d code's output.

If you want other objects hidden-surface removed by the pm3d polygons, 
you can just feed those polygons to the hidden3d engine as they are, but 
flagged as invisible (like with the 'trianglepattern 0' option of 'set 
hidden3d').

The only real alternative would be to a full-featured, object-precision 
3D rendering engine to replace both pm3d (polygons) and hidden3d 
(wireframe) output.  Such a beast would probably be even slower than 
hidden3d already is.