Transformation matrix object offset ?

[CinnamonMetal]

I'm importing a vector4 as a point matrix within a VOP SOP; but it's position as in the transformation matrix, does not align correctly with the object prior to the transformation matrix ?

The problem is in this VOP network, as the problem is only experienced in this VOP Network ?

[tamagochy]

if amatrix vector4 you should convert it to matrix. Vector4 its only rotation without translate.

[CinnamonMetal]

Amatrix is a Matrix attribute but it's not translating back to the original position, as it should ?

[tamagochy]

So your matrix havent translate. How you build it?

[CinnamonMetal]

I built it with expressions on parameter retrieving specific point values for up, aim an side vectors. Along with cross products then created an attribute for each axis. You are right, the object is not translating to the original position ?

[jamesr]

up aim and side vectors won't translate your object. can you post a hip?

[CinnamonMetal]

In any case so far shown I'm not getting the transformation matrix to result back to it's original position.

[tamagochy]

To back to original position you need to create 2 matrices first for original object, second for translated and use this

@P*=invert(trans_mat)*orig_mat;

But often you need move translated obj to origin, make something with it and back to position. And what I show you early for this case. 

[CinnamonMetal]

@tamagochy What do you mean by (trans_mat) the matrix attribute * matrix attribute ? Also what method are you referring too, you gave one method but I posted another ?

[tamagochy]

@CinnamonMetal

You want back your object to origin position before translation, but you can do it if you have matrix for this position. If you havent you never get this. Simple explanation is: you can back to position you made matrix for. 

[CinnamonMetal]

@tamagochy I'm inversing the matrix should that not be getting back the original position ? Otherwise I didn't quite understand what you meant ?

[tamagochy]

@CinnamonMetal

Inverse matrix move object to origin {0,0,0} and align z and y axis of your matrix with global z and y axis, So if you haven't matrix of the object in origin point it's not back to origin position, because your matrix, created on the transformed object not aligned with global axis.