select the object, then run this MEL command.

xform -q -ws -m;

@mikesnail,

I have a partner handling the Maya wrangling. I have my own 3D code (Objective-C) that consumes the above data. All I really need to know is the order of matrix concatenation.

For example is it (ignoring scale for the moment): T * Rx * Ry * Rz -> TransformationMatrix?

Where can learn more about the API? Is there an Objective-C binding?

Cheers,
Doug

@MinsieurH,
Thanks very much. I am actually working with a partner on this project who is handling the Maya end. I have my own custom 3D software that takes a 4x4 matrix as input. What should I tell my partner to setup the composeMatrix node?

-Doug

@MinsieurH,

I just tried Google’ing composeMatrix node and found nothing (?). I also could not find any mention of it in the Maya help docs.

I went ahead and downloaded Maya2013 for my Mac and loaded the .ma file from my partner. How do I setup the composeMatrix node? What exactly does it do?

For context, I am an experienced 3D graphics programmer new to Maya.

Cheers,
Doug

@Avotas,

Actually all I want to do is be able to start at the 16 numbers corresponding the the transformation matrix of of the following:

- my camera
- single rectangle it is aimed. 

I just downloaded a shiny new copy of Maya20123. I have loaded my trivially simple seen file into Maya.

Now, how do I display the 16 numbers of the transformation corresponding to each.

Surely I don’t have to resort to writing a mel/python script just to see these numbers! That seems like massive overkill for what is very, very, simple question or am I missing something?

Cheers,
Doug

Hi Doug,

The reason I referenced the other form is because of the skill set of the people who populate it. This is a generalist form, mostly populated by artists who may or may not know what a transformation matrix is ... except maybe a famous movie franchise tie-in. (That’s not a slam against anyone, its just outside the normal scope of knowledge for most)

To visually see how everything exists in Maya:

• Click Window -> Hypergraph:Connections.
• Select the nodes you want to examine, then select Graph -> Input and Output Connections.
• Clicking on these nodes will expose the values in the Channel Box editor (right side-bar, main render window). Clicking the connecting lines demonstrate how Maya handles the connections between them.

vvv Everything below this line is guesswork, it has been a decade sense I worked with matrix’s, so take it with a grain of salt. vvv

Now that you can see the data, you just need to convert your row-major (X,Y,Z,T) format into a 4x4 matrix.

(X,Y,Z,T)
(m0, m1, m2) : +X axis, left vector
(m4, m5, m6) : +Y axis, up vector
(m8, m9, m10) : +Z axis, forward vector