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From: Rune Allnor <allnor@tele.ntnu.no>
Newsgroups: comp.soft-sys.matlab
Subject: Re: Import a 3D model into Matlab and rotate/translate it
Date: Fri, 10 Oct 2008 15:12:32 -0700 (PDT)
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On 10 Okt, 23:56, "Alexander " <alexander.erl...@gmail.com> wrote:
> Thank you Rune,
>
> > In practice there are two problems: Obtaining the
> > file format descriptions and selecting what data
> > structures to use internal to matlab.
>
> yeah, I've seen that there is a file converter from CAD to Matlab, but I understand that there is no simple, Mathworks-predefined way. So I guess I'll have to change my plans a little.

Not necessarily. It is perfectly possible to write
your own routine to read the files if you can get
the file format spec.

> > Probably. Just be aware that 3D graphics is one
> > of the more demanding computational tasks around,
> > both what memory and algorithms are concerned, and
> > that matlab is notoriously inefficient what memory
> > and algorithms are concerned.
>
> Actually, if sometime in the distant future I will realize doing the 3D grapics stuff in Matlab is too slow, is there an easy way to use a different renderer, like openGL? I mean, can I operate and update things from Matlab just like I described it, but address openGL directly?

'Easy' and 'fast 3d graphics' are contradictions in terms.
You can configuure matlab to use the openGL renderer,
but the bottleneck is not necessarily to render the graphics,
but several factors distributed more or less evenly throughout
everything, from data formats (matlab uses matrices of double-
precision floating points by default) to memory access (you have
to pay very carful attention to how you store stuff or you might
get cache misses on every other data access).

Rune