Frustrums and dot products.
Ok.
Anybody will know that I genuinely suck at math when they read this. But that is why I am asking for help!
I''ve roughly implemented a quick ''n dirty frustrum culling algorithm.
I know my lookat vector and my vectors created from the camera to vertices of a node (lets say they''re v1,v2,v3,v4).
My question is:
1) Do I DotProduct the lookat vector and v1,v2,v3 and v4?
2) Or do I DotProduct (lookat vector - camera position) and
v1,v2,v3, and v4?
This is what I have so far, and it doesnt work exactly the way it should.
-----------------------------------------------------------
D3DVECTOR c = camera.getPosition();
D3DVECTOR lookat = camera.getLookAt();
// Check if less < 90 degrees or > 270 degrees (viewable).
if ((dotProduct(lookat-c,v1) > 0) ||
(dotProduct(lookat-c,v2) > 0) ||
(dotProduct(lookat-c,v3) > 0) ||
(dotProduct(lookat-c,v4) > 0))
{
// one or more vertex is inside the frustrum!
return TRUE;
}
else
return FALSE;
------------------------------------------------------------
~ I''''m a wannabe programmer ~
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