Steve Baker (steve++at++mred.bgm.link.com)
Fri, 10 Jan 97 09:25:19 -0500
> In my application I want to draw a polygon
> with 5 vertices. The geoset of this polygon looks like this
<snip>
> Coord 0: X: -1.750000 Y: 0.000000 Z: -1.300000
> Coord 1: X: 0.800000 Y: 0.000000 Z: -0.950000
> Coord 2: X: 1.550000 Y: 0.000000 Z: 0.700000
> Coord 3: X: -1.300000 Y: 0.000000 Z: 1.650000
> Coord 4: X: -2.350000 Y: 0.000000 Z: 0.600000
<snip>
> The problem that Performer draws this polygon with a hole in it.
It looks like the polygon has been chopped up into triangles incorrectly.
For those who didn't decode Bruno's JPG file, the five vertices look
something like this:-
D
C
E
B
A
The system appears to have generated 3 triangles A-B-C, B-C-D and C-D-E which
doesn't draw any pixels between A and E and renders those between C and D and
between B and C twice.
The is obviously **WRONG** - it looks like a Performer error.
I can't *see* anything wrong with the polygon definition - although it's a
little unusual not to have any colours on the geoset, I don't think that's illegal.
For a work-around, I'd suggest splitting complex polygons into simpler triangles
yourself - that is usually more efficient anyway since you only have to split
them once (when you create them) instead of Performer having to split them up
every frame.
Steve Baker 817-619-1361 (Vox-Lab)
Hughes Training Inc. 817-619-8776 (Vox-Office/Vox-Mail)
2200 Arlington Downs Road 817-619-4028 (Fax)
Arlington, Texas. TX 76005-6171 Steve++at++MrEd.bgm.link.com (eMail)
http://www.hti.com (external) http://MrEd.bgm.link.com/staff/steve (intranet)
http://web2.airmail.net/sjbaker1 (external)
"You can't destroy the Earth - that's where I keep all my stuff!" - The Tick.
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