SHEAR Matrix transform support or work around?

Hi,

so this is a python / tdu / matrix question:

I come from a 3d background and I’m used to parenting 1 object to another with the child maintaining it’s overall placement visually or according to world space.

I’ve worked out how to do this fairly easily in touch by multiplying inverse matricies and such - the problem arises when my intended parent object has non uniform scale AND rotation.

This introduces the need (I think?) for a 4th set of params called shear:

-translate
-rotate
-scale
[shear]

These are my results in TD:

These are my results with same coordinates in MAYA:

Is there any way to do this in TD 099 30400 or similar?
Or is it possible to manually do this xform to matricies with tdu.Matrix class then apply it somehow?

Thanks!

Lucas
parentingObjectsInPlace.2.toe (4.47 KB)

Sort of just guessing here…

[url]http://download.autodesk.com/us/maya/2011help/api/class_m_transformation_matrix.html[/url]

Suppose your shear in Maya is [sx,sy,sz],

Maybe this autodesk documentation says that’s [shyz,shxz,shxy]

(look for this in the autodesk site)

tdu.Matrix(
[1, 0, 0, 0,
shxy, 1, 0, 0,
shxz, shyz, 1, 0,
0, 0, 0, 1])

Then maybe you can “decompose” that via TD:
[url]https://www.derivative.ca/wiki099/index.php?title=Matrix_Class[/url]