Michael Goldfarb

you could reference the bounding box of the input to the HDA

see: https://www.sidefx.com/docs/houdini/expressions/opinput.html [www.sidefx.com]

turn OFF Deform Patch on the PolyFill - that should make a flat surface.

the first issue is that the ‘geo_skin’ node's selection flag is OFF - this will prevent selecting points, you should turn this back on.

when manually adding bones you must only add the bones you want to use as source bones to the From field
and only add bones you want to use as the destination to the To field
eg:
From : “Head_Head_bone/cregion 0”, “L_Arm_clavicle/cregion 0”
To : “Head_Head_bone/cregion 0”, “R_Arm_clavicle/cregion 0”

Note that in this example the head in is both fields - you'll want and bones in the middle to be in both fields
“L_Arm_clavicle/cregion 0” is in the From field
“R_Arm_clavicle/cregion 0” is in the To field

this will take the weights from the Left and send them to the Right.

hope that helps

this tutorial was just published if you haven't seen it yet:
https://www.sidefx.com/tutorials/rigging-series-2-capturing-geometry/ [www.sidefx.com]