Flipping a transformation matrix

[seltzdesign]

For interchanging transformation data between vvvv and another software I am exporting transformation matrixes as text files. While working on the exporter I noticed that vvvv represents transform matrixes differently to everyone else. The matrix is flipped.

Anyone know of a quick way to flip it back (columns become rows)? How come vvvv uses that format?

[tekcor]

Hi,
I was doing it the other way around (DirectX to OpenGL style matrix) with this little patch snipet.
It is spreadable this way.
Didnt finish the thought if it would be correct if you use this patch the other way around, but theoretically it should. If not it might be a starting point for an alternative way of swizzling the vectors.

MatrixConvert.v4p (108.5 KB)

[antokhio]

have you try transpose node, should do exactly that

[tonfilm]

yes, its simply a Transpose (Transform) node.

here is some more on the topic:

Understanding vvvv's Transformation Matrices

there are a few things you have to separate: left-handed and right-handed has nothing to do with the matrix layout OpenGL has col-major notation, DirectX row-major notation. that means the matrix element names are transposed you need to make sure which notation is used in your target coordinate system matrix multiplcation does exactly the same in both cases you need to know how the XYZ axis are aligned in both coordinate systems vvvv uses DirectX conventions: left handed coordinate system w…

[seltzdesign]

@tekcor @antokhio Thanks everyone for the quick replies. Transpose does the trick ;)

@tonfilm thanks for the link to the indepth explanations. As if all this stuff wasn’t difficult enough, they have to make it different in different software. Not even talking about working between Rhino and Maya, where the axis are different. Looots of trial and error involved ;)