Hello!

I am working on a FBX converter. So, the target is FBX, and the input is a format that has LOCAL MATRICES.

So the rotation, translation and scaling is stored into 4x4 Matrix. Usualy everything goes right except there

are some situations, where objects are turned for 90 or 180 degrees in the wrong direction.

The easisest thing for me would be if I could say: FbxNode->SetLocalMatrix() .

But there is no souch function. I can only say: SetTranslation, SetRotation, SetScaling

and they all require vectors for input. What to do?

I create a FbxAMatrix (affine matrix) and then get the Translation and Rotation vector

out of it. Of course, the rotation is not allways right.

My Idea was, to create a vector with [1,1,1] and then transform it by the original matrix,

get "OriginalOutputVector" and then take the same vector [1,1,1] and transform it

by the Affine Matrix to "AffineOutputVector" and compare them. So I would get

when the affine decomposition went wrong. But how to solve that?

Feel free to post.

Thank you in advance!

Hello!

Thank you for your reply. It's like this:

I set the FbxAMatrix with float[16] from my source file:

float f[16]; fread(f, 4, 16, fp); FbxAMatrix m; m[0] = FbxVector4(f[0],f[1],f[2],f[3]); m[1] = FbxVector4(f[4],f[5],f[6],f[7]); m[2] = FbxVector4(f[8],f[9],f[10],f[11]); m[3] = FbxVector4(f[12],f[13],f[14],f[15]);

Sofar so good. The FbxAMatrix is set correct, no problems there.

The problems appear when I try to set that roatation and translation data into the FbxNode.

Let us take a test vector[1, 2, 3]

The source matrix is like this:

-0.2016 -0.5842 -0.7862 0.0000
-0.2564 -0.7432 0.6180 0.0000
-0.9453 0.3261 -0.0000 0.0000
0.3173 -0.0200 -0.3904 1.0000

If I put it against the source matrix i get: [ -3.2331, -1.1121, 0.0593] which is correct.

Now I take the source matrix and say:

FbxVector4 r = src->GetROnly();
FbxVector4 t = src->GetT();

node->LclTranslation.Set(t);
node->LclRotation.Set(r);

What I get is a FbxNode matrix like this:

-0.2016 -0.5842 -0.7862 0.0000
-0.0496 -0.1438 0.1196 0.0000
-1.7902 0.6176 -0.0000 0.0000
0.3173 -0.0200 -0.3904 1.0000

If I now take the vector [1,2,3] and transform it over the matrix I get: [ -5.3543, 0.9612, -0.9375] which is not the same.

Vector comparison:

A [ -3.2331, -1.1121, 0.0593]
B [ -5.3543, 0.9612, -0.9375]