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# View-Frustum-Culling????

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Bas - you''re not entirely correct. You COULD do clipping in screenspace to eliminate the need for view frustum culling, but then, what''s the point in doing any kind of VSD?

Culling becomes clipping when polygons are only partially visible - so they are related.

#pragma DWIM // Do What I Mean!
~ Mad Keith ~
**I use Software Mode**

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Hi XBTC,
View Frustum Culling with a BSP Tree?

Well, you could check whether a space partition plane hits your view frustum. If not, you can ignore drawing the polys in this plane. Apart from that you can continue drawing/testing with only one of the two subtrees, because the other one cannot hit the frustum.

I guess there are still other methods to accelerate tree traversal.

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Thanx!
and Yes I know I can cull nodes lying outside the VF,BUT the only thing I wanted to know is HOW!!!!

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So there is the prob.

Ok! Your planes should have a normal. So you have a positve and a negative side of your plane.
Now you just have to calculate on which side the 8 frustum corners are. When all points of the fustum are on one side the plane doesnt hit the frustum. But when you have points on both sides of the plane, you can't cull it.

Here is a formula to calculate on which side and at which distance a point is located towards a plane.
you need to have the normal and the variables a,b,c and d from this plane equatation: x*a + y*b + z*c + d = 0

The normal should be a unit vector, when you need exact distance returns.

distance = DOTPRODUCT(normal,point ) + d;

Sorry that my english is so bad, when you want a more detaild explanation send me a mail.

Edited by - TheMummy on May 9, 2000 9:25:59 AM

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Thanx alot!This was exactly what I wanted to know.
P.s.:If somebody knows something about how to optimize the procedure pleas let me know
P.P.S.:There is no Problem with your english I think,which
is nothing you can count on,´cause I am(you wouldn´t
guess) from B,too.

Edited by - XBTC on May 10, 2000 8:33:51 AM

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WHAT ???? You too ?

I always thought that I am the only programmer in Bavaria!

;-)

Where do you live? I live near Landshut in a small town.

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I live in a small town,too,near Munich!
And you´re right I don´t know a programmer except myself who lives in my region!

Edited by - XBTC on May 12, 2000 5:24:34 PM

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