Viewport xform Python expression

[woodenduck]

Hi, 

I have created a geo node who's world transforms are matched to those of the current viewport, using the following Python.

import toolutils 

viewer = toolutils.sceneViewer() 
viewport = viewer.curViewport() 
xform = viewport.viewTransform()

obj = hou.node("/obj").createNode("geo")

obj.setWorldTransform(xform)
 

So far so good...

Now I want to set these values with Python parameter expressions on the object so that the transforms are updated when the viewport is tumbled. The problem I'm facing is when I try to access the individual components of the xform matrix to set as the object parm I get "the Matrix4 object is not iterable"...???

Any ideas how I can dynamically link an objects transforms to those of the viewport?

Thanks for any tips, 

WD

 

 

 

[cosku]

You'd need to extract translation & rotation from that matrix,

Like, for tx:

import toolutils 
viewer = toolutils.sceneViewer() 
viewport = viewer.curViewport() 
xform = viewport.viewTransform()
return xform.extractTranslates()[0]

for ry:

import toolutils 
viewer = toolutils.sceneViewer() 
viewport = viewer.curViewport() 
xform = viewport.viewTransform()
return xform.extractRotates()[1]

etc.

[woodenduck]

Thanks @cosku, 

This is exactly what I was looking for. 

Cheers!

WD