Re: Implementing Browsers
Vassilis Bourdakis ([email protected])
Sun, 4 Jun 1995 20:38:18 +0000
Rycharde Hawkes wrote:
>
>Bernie mentioned that 3D studio uses triangles only. Whereas
>this suits most people it is actually a pain for me. Our IG supports
>convex polygons with any number of vertices. In fact, it is optimised for
>this since the overhead of setting up a large number of polygons (to make a
>circle for example) is larger than rendering one polygon with many vertices.
>This means that I need to do some pre-processing on the model from 3DS
>if I am to get better performance. Merging triangles into large
>polygons can be fairly time consuming (if you aren't given any
>associative information, as in tristrips) and of course you always have
>to check that the resultant polygon is planar.
>
>> Clearly, we want to keep the file sizes small. However, I think it's
>> even more critical that we keep the rendering speed high; having to
>> decompose the polygons at render time would slow things down.
>
>It would seem sensible to me that the polygons should be convex and have
>as many vertices as you want. After all, converting a multi-vertex polygon
>into a set of triangles is a lot quicker than vice-versa.
>
Actually 3DS does create multi vertex polygons... simply the way it sets the
normals is a bit dodgy... Thats all. It does _NOT_ work on simple individual
triangles!
Apart from that it works fine.
The problem is with many of the ACAD models that are indeed simple triangles.
In order to create multivertex polygons in ACAD,
you need to do some (rather a lot) programming yourself...
Apart from that I agree with all you said..
>
>Rych
>
>=====================================================================
>Rycharde Hawkes Virtual Environment Laboratory
>email: [email protected] University of Edinburgh
>Tel : +44 131 650 3426 Fax : +44 131 650 6534
> WWW : http://hagg.psy.ed.ac.uk/
>
> "Rome wasn't built in a day, but if they'd just worked harder..."
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