*sigh* I'm lost again.
This time, I'm trying to extract the frustum's 8 corners, and I'm just not quite there.
What's especially irritating me, is I've copied this code from a previous project, where it worked, and here - zilch.
Here's what I'm doing:
1) Extract the View and Projection matrices, and send them to my building class:
m_Device->SetTransform(D3DTS_VIEW, &MatView);
D3DXMATRIX MatProj;
m_Device->GetTransform(D3DTS_VIEW, &MatProj);
D3DXMatrixMultiply(&MatProj, &MatView, &MatProj);
m_Frustum.Create(MatProj);
2) Build the actual frustum:
- Now, what I'm doing is transforming 8 points with the [-1.0f 1.0f] range by the inverse of the combined View Projection matrix. This *Should* give me the 8 frustum corners (I think!). Heres the code:
bool cFrustum::Create(D3DXMATRIX CombMat)
{
D3DXMATRIX InvCombMat;
D3DXMatrixInverse(&InvCombMat, 0, &CombMat);
D3DXVECTOR3 vec = D3DXVECTOR3(1.0f, 1.0f, 1.0f);
D3DXVec3TransformCoord(&vec, &vec, &InvCombMat );
m_AABB = cAABB(vec);
vec = D3DXVECTOR3(-1.0f, 1.0f, 1.0f);
D3DXVec3TransformCoord(&vec, &vec, &InvCombMat );
m_AABB.Expand(vec);
vec = D3DXVECTOR3(1.0f, -1.0f, 1.0f);
D3DXVec3TransformCoord(&vec, &vec, &InvCombMat );
m_AABB.Expand(vec);
vec = D3DXVECTOR3(-1.0f, -1.0f, 1.0f);
D3DXVec3TransformCoord(&vec, &vec, &InvCombMat );
m_AABB.Expand(vec);
vec = D3DXVECTOR3(1.0f, 1.0f, -1.0f);
D3DXVec3TransformCoord(&vec, &vec, &InvCombMat );
m_AABB.Expand(vec);
vec = D3DXVECTOR3(-1.0f, 1.0f, -1.0f);
D3DXVec3TransformCoord(&vec, &vec, &InvCombMat );
m_AABB.Expand(vec);
vec = D3DXVECTOR3(1.0f, -1.0f, -1.0f);
D3DXVec3TransformCoord(&vec, &vec, &InvCombMat );
m_AABB.Expand(vec);
vec = D3DXVECTOR3(-1.0f, -1.0f, -1.0f);
D3DXVec3TransformCoord(&vec, &vec, &InvCombMat );
m_AABB.Expand(vec);
return false;
}
Now, the vaules being spit out of these transformations are, I think, wrong. My camera is set up at a height (Y) of about 40.0f. The view depth is 100.0f, and it's looking about 45 degrees down (3D RTS style camera). Now, I'm getting Y values of around 58.0f - 60.5f for my corners. All 8. This isn't right...
Any ideas on this? Is the basic math correct? Thanks a bunch guys! :).
