Xform pivot

[6ril]

Hi,

 

I'm trying to learn, but I sometimes find it hard to get answers from the doc (real good doc tho).

 

here is what I'm struggling with at the moment:

 

I want the pivot of a transform node to to be placed relatively to another object (in the same geo node).

 

I need the pivot to be at XMIN in x axis, 0 in y axis, ZMIN in z axis.  Easy. But I need the XMIN and ZMIN of another object.

 

Can someone help me with the syntax ?

 

thanks !

Edited March 27, 2016 by 6ril

[6ril]

here is a hip file to make it easier.

 

I wrote:

XMIN of box1

to show you want I need, in the transform node.

I need help with the syntax.

 

something like that ?  op:"../box1"($XMIN)

 

*edit*

Or is it not possible this way because the help says: $XMIN is the min on x of the node input ?

XMIN.hipnc

Edited March 27, 2016 by 6ril

[f1480187]

bbox is what you are looking for:

bbox("../box1/", D_XMIN)
bbox("../box1/", D_ZMIN)

[6ril]

thank you !

 

Does it mean that $XMIN is only usable from the node input?

[f1480187]

Yes, it is for inputs. It is a local variable defined on the Transform SOP node. You cannot use it outside the node except some other nodes define their own $XMIN. List of node's locals can be found in docs.

[jrockstad]

The local / global variable system in Houdini can be a bit confusing at first. Peter Quint discusses this a bit in his videos on attributes, the first of which you can find here:

 

https://vimeo.com/6803463

 

 

[6ril]

thank you guys : )