I'll be brief. I'm new to Houdini.

Where are the relationships between object established?
Stated another way, where are variables created?
The syntax is wrong but what I'm trying to do should be clear enough.

an example: box1length=2
box2length=box1length*3

or: ptaloc5,5,5)
translate objectx to ptaloc

the way Houdini does this is through Channel References
http://www.sidefx.com/docs/houdini/network/expressions [www.sidefx.com]


in your example:
box1Object -> inside there will be a box SOP, the box SOP has parameters for Size (sizex, sizey, sizez)

box2Object -> inside you have a box object, you can use channel references to drive the parameters:
–> box2Object/box –> sizex parameter : ch(“/obj/box1Object/sizex”)

this is an absolute reference, what you will more commonly see is a relative reference: ch(“../../box1Object/box1/sizex”)

an easy way to see how this works is to RMB on the size parameter name of boxObject1/box and select Copy Parameter
now go to the box2Object/box and RMB on the size parameter and see that there are a number of options including:
Paste Values
Paste Expressions/Channels - this will make an absolute reference
Paste Relative Reference - this will make a relative reference

hope that helps

Thanks for the info. I'm certain that I'll have more questions later.