CODEWITHSUNDEEP
c++vector3dmatrixdirectx
Hooch
Hooch

Reputation: 29693

3D - Rotation Matrix from direction vector (Forward, Up, Right)

I need to get rotation matrix from direction vector (vForward) I also have vRight and vUp vectors. All those vectors are unit vectors.

I just need to get rotation matrix.

To get rotation matrix for rotation in only one plane (xy) parallel to ground, I do this: XMMATRIX xmResult;

Vec3f vFwd = pPlayer->VForward;
vFwd.z = 0;
vFwd.Normalize();

xmResult = XMMatrixSet( vFwd.y,     -vFwd.x,    0,      0,
    vFwd.x,      vFwd.y,    0,      0,
    0,          0,          1,      0,
    0,          0,          0,      1);

Above code only get rotation matrix to rotate around Z axis:

I would like to get the code to rotate around all axis. This is coordinate system I'm forced to use. I know it is strange:

Coordinate System I'm using

This is how I'm using my matrix later in code:

XMStoreFloat3((XMFLOAT3*)&vStart, XMVector3Transform(XMLoadFloat3((XMFLOAT3*)&vStart), xmTransformation));
XMStoreFloat3((XMFLOAT3*)&vEnd, XMVector3Transform(XMLoadFloat3((XMFLOAT3*)&vEnd), xmTransformation));

Upvotes: 6

Views: 9377

Answers (1)

Andreas Brinck
Andreas Brinck

Reputation: 52549

Depending on how you use your matrices, Right, Up and Forward should correspond to the rows or columns of your matrix.

xmResult = XMMatrixSet( vRight.x, vRight.y, vRight.z, 0, vFwd.x, vFwd.y, vFwd.z, 0, vUp.x, vUp.y, vUp.z, 0, 0, 0, 0, 1);

Upvotes: 5

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