Re: [Gnuplot-info] output 3d coordinates corresponding to the projected 2d coordinates, z buffering

[Hans-Bernhard B. <HBB...@t-...>]

Am 11.11.2015 um 00:04 schrieb A. Sillem:

> When using the TikZ terminal, a file is generated which uses 2d
> coordinates which originate from the projection of the 3d coordinates
> into the 2d view plane. Instead of the 2d coordinate output, I would
> like to output table data of the 3d coordinates corresponding to ONLY
> the projected 2d coordinates, not to ALL the 3d coordinates like you get
> with the table terminal.

This idea suffers from at least a slight misconception.  There is no 
such thing as "ONLY the projected 2d coordinates" because ALL 3d 
coordinates are always projected.  Hidden3d may not actually use all of 
them to draw stuff, but first, they're all projected.  They have to be 
for hidden line removal to have something to work with.

And maintaining coherency of input datasets across hidden line removal 
is not something the hidden3d algorithm in gnuplot is anywhere near 
prepared to support.

I don't really see what you hope to achieve by this.  If you want 3D 
data output, you'll have some 3D capable tool to display them with.  If 
that 3D display tool can't even do its own hidden line removal, why 
would you use it?  If it can, what good would it do to have gnuplot run 
its own one beforehand?  It would just throw away about half the data 
the other tool is supposed to work with, most likely making its job 
impossible in the process!