Hi guys,
I am having huge difficulties implementing working frustum culling.
I have following code every frame:
CalcFrustum()
{
//matview = view matrix
// vEyePt - position where viewer stands (camera)
// vLookatPt - position to look at
// vUpVec - vector (0,-1,0) for orientation
D3DXMatrixLookAtLH( &matView, &vEyePt, &vLookatPt, &vUpVec );
//matProj = projection matrix
// fovy - D3DX_PI/4
// aspectxy - screenx / screeny
// zmin - 1.0f
// zmax - 100.0f
D3DXMatrixPerspectiveFovLH(&matProj, fovy, aspectxy, zmin, zmax);
//
D3DXMATRIX ViewProjection;
D3DXMatrixMultiply( &viewProjection, &matView, &matProj );
// Left plane
frustumplane[0].a = viewProjection._14 + viewProjection._11;
frustumplane[0].b = viewProjection._24 + viewProjection._21;
frustumplane[0].c = viewProjection._34 + viewProjection._31;
frustumplane[0].d = viewProjection._44 + viewProjection._41;
// Right plane
frustumplane[1].a = viewProjection._14 - viewProjection._11;
frustumplane[1].b = viewProjection._24 - viewProjection._21;
frustumplane[1].c = viewProjection._34 - viewProjection._31;
frustumplane[1].d = viewProjection._44 - viewProjection._41;
// Top plane
frustumplane[2].a = viewProjection._14 - viewProjection._12;
frustumplane[2].b = viewProjection._24 - viewProjection._22;
frustumplane[2].c = viewProjection._34 - viewProjection._32;
frustumplane[2].d = viewProjection._44 - viewProjection._42;
// Bottom plane
frustumplane[3].a = viewProjection._14 + viewProjection._12;
frustumplane[3].b = viewProjection._24 + viewProjection._22;
frustumplane[3].c = viewProjection._34 + viewProjection._32;
frustumplane[3].d = viewProjection._44 + viewProjection._42;
// Near plane
frustumplane[4].a = viewProjection._13;
frustumplane[4].b = viewProjection._23;
frustumplane[4].c = viewProjection._33;
frustumplane[4].d = viewProjection._43;
// Far plane
frustumplane[5].a = viewProjection._14 - viewProjection._13;
frustumplane[5].b = viewProjection._24 - viewProjection._23;
frustumplane[5].c = viewProjection._34 - viewProjection._33;
frustumplane[5].d = viewProjection._44 - viewProjection._43;
// Normalize planes
for(int i=0;i<6;i++)
{ D3DXPlaneNormalize(&frustumplane, &frustumplane);
}
}
and then I have following code for checking if vertices are within the frustum:
bool CheckFrustum(float x, float y, float z)
{ D3DXVECTOR3 vector;
int i;
//
vector.x = x;
vector.y = y;
vector.z = z;
//
for(i=0;i<6;i++)
{ if(D3DXPlaneDotCoord(&frustumplane, &vector) < 0 )
{ return FALSE;
}
}
return true;
}
But the problem is, it doesn't really work. The vertices that are being culled are wrong: sometimes too early, sometimes too late.
Could anybody please help me with this ?
[Edited by - Zaph-0 on July 23, 2008 7:55:02 AM]
