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OpenGL Frustrum culling between DX and OpenGL

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revearz    122
Hi, I am trying to port my frustrum generation code from DirectX to OpenGL. My reference for the frustrum generation is from which works great in DirectX. When I tried to port it over to OpenGL ( using the code provided in the paper ), some of my frustrum planes are different. Before normalizing the planes: - Top and Bottom planes are same - Near and Far planes in OpenGL is double the size of DX ( but they will equal after normalization ) - Left and Right are totally different. Anyone encountered a similar problem? Might just be some silly mistake that I made but I've been trying to debug it for a few days without luck. Thanks. [edited by - Revearz on March 30, 2004 1:11:54 AM]

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revearz    122

The function CalculateFrustum() provided in the tutorial seems to calculate the same thing as provided in Any ideas on what else the problem would be?

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revearz    122
Do you mean row-major vs. column-major? If so, I tried transposing the view*proj matrix and did not get correct frustrum planes.

If you mean ( view * proj ) vs. ( proj * view ), I tried that too.

It's only the left and right frustrum planes that are not equal. Wonder why .....


Just wondering what values you get for the plane with the following variables:

camera pos = ( 76.035828f, 95.931946f, 219.078842f )
camera reference = ( -100.566727f, 71.477310f, 177.845230f)
camera up = ( 0, 1, 0 )
lookat = reference - pos

near = 1.0f
far = 300.0f
FOV = PI / 4
aspect = 1.7647058

[edited by - Revearz on March 30, 2004 3:57:22 AM]

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