Convert rotations from right hand to left hand?
Author
Is there a way to calculate the rotation values in a left handed system, given the rotation values in a right handed system? HOW? Thanks!
Hi,
I had the same problem with a Maya exporter -> DirectX (Maya = right handed, DirectX = left handed.
For the rotation, I found the following : If you have your rotations around each axis, and applied in the order : X, Y then Z, in a right handed system, then in a left handed system, it will be : X, -Y, -Z.
I did found that in a totally empiric way, but I've been using my exporter since half a year now, and I've never had any problem.
I had the same problem with a Maya exporter -> DirectX (Maya = right handed, DirectX = left handed.
For the rotation, I found the following : If you have your rotations around each axis, and applied in the order : X, Y then Z, in a right handed system, then in a left handed system, it will be : X, -Y, -Z.
I did found that in a totally empiric way, but I've been using my exporter since half a year now, and I've never had any problem.
Author
Yeh thats what we're doing. Using Maya for our level editor in a DirectX based game. I tried what you said and it doesn't seem to work, can you show me exactly how you grabbed the rotation values from maya? Also, how were you constructing your projection/view matrices in DX? RH or LH?
Can you just use a right hand coordinate system instead (rather than converting everything)? We had the same Maya problem, and switching our game to the LH system was pretty painless; 2 steps really (if I remember correctly):
1) Switch the D3DX functions that end in RH to LH
2) Switch the renderstate for culling to the reverse of what you have
I think that's pretty much all I did and never had a problem afterwards. The only downside is that mesh viewer uses a LH system, so it lessens it's value as a tool slightly.
NOTE: This assumes you use the D3DX functions for creating your transform matricies.
Matt Hughson
1) Switch the D3DX functions that end in RH to LH
2) Switch the renderstate for culling to the reverse of what you have
I think that's pretty much all I did and never had a problem afterwards. The only downside is that mesh viewer uses a LH system, so it lessens it's value as a tool slightly.
NOTE: This assumes you use the D3DX functions for creating your transform matricies.
Matt Hughson
Author
Maya uses RH system though, and we were using D3DX functions to convert between RH and LH in our game. Neither is working for us though. I need help!
Ok, here's the function which extract a transformation matrix from a dagPath, and convert it to left handed :
MFnTransform transform(dagPath); float mat[4][4]; MEulerRotation eulerRotation; double scale[3]; MVector translation; // extract the transformations from the transform transform.getRotation(eulerRotation); transform.getScale(scale); translation = transform.translation(MSpace::kWorld); // convert it to left handed translation.x = -translation.x; eulerRotation.y = -eulerRotation.y; eulerRotation.z = -eulerRotation.z; // rebuild a transformtion matrix from the modified transformations MTransformationMatrix transformationMatrix; transformationMatrix = transformationMatrix.identity; transformationMatrix.rotateBy(eulerRotation, MSpace::kWorld); transformationMatrix.setScale(scale, MSpace::kObject); transformationMatrix.setTranslation(translation, MSpace::kWorld); // extract the new matrix MMatrix mayaMatrix = transformationMatrix.asMatrix(); mayaMatrix.get(mat); // store it matrix._11 = mat[0][0]; matrix._12 = mat[0][1]; matrix._13 = mat[0][2]; matrix._14 = mat[0][3]; matrix._21 = mat[1][0]; matrix._22 = mat[1][1]; matrix._23 = mat[1][2]; matrix._24 = mat[1][3]; matrix._31 = mat[2][0]; matrix._32 = mat[2][1]; matrix._33 = mat[2][2]; matrix._34 = mat[2][3]; matrix._41 = mat[3][0]; matrix._42 = mat[3][1]; matrix._43 = mat[3][2]; matrix._44 = mat[3][3];This topic is closed to new replies.
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