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ByteMe95

err, I got a real bad case of the jaggies

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I dont know why, but in my model viewer, usually on high polygon models when I rotate them or zoom out on them at certain amounts, a bunch of triangular fragments start to show up and makes it look really bad. Here is a screen shot of a ufo model I loaded. The first one is what it looks like straight on: This is what it looks like zoomed out and rotated a bit: (Click on the pictures to get a better view) So you can see what I mean now hopefully. I''m using dx8, but I noticed the same problem when using OpenGL too, so what''s the dilly yo? ByteMe95::~ByteMe95() Cerebrum Software

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Guest Anonymous Poster
make sure your zbuffer is using 32bit values.

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I don''t know if this will help, but maybe the model is too large. If you''re using floating point numbers in the hundreds, this may happen. It''s happened to me before. Just scale the model down and it may cure the problem. It could also be the way you cull the faces. Anyway, good luck. Hope this helps.

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Guest Anonymous Poster
It almost looks like a Z buffer accuracy problem. Try moving your far clipping plane in closer and your near clipping plane in out a bit.

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Guest Anonymous Poster
Yes, if the range between your near and far clipping planes is too large, even a 32bit zbuffer will have accuracy problems

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Scaling it down actually worked pretty well, im surprised.
I dont get why it would make a difference since it all ends up looking the same on screen if u zoom in enough after scaling it down. actually, i guess all the z-buffer calculations are done in 3d space so it would matter, that''s annoying.
oh well
thanks guys

ByteMe95::~ByteMe95()
Cerebrum Software

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Guest Anonymous Poster
It''s all got to do with significant digits.

the larger the range of values being stored the less accurate the floating point numbers get. that is why things appear jagged, with a wide range of values your zbuffer may only be accurate to one or two decimal points, this causes the jagged artifacts you describe. if you decrease the distance between the near and far clipping planes you decrease the range of numbers in the zbuffer, hence making it more accurate, say maby 4 or 5 decimal places wich makes the jagged artifacts go away.

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