…so that when I scale the actual “Source” prim, it doesn’t scale from its internal pivot equally on all axes, but in relation to that external pivot, like so (for show and tell purposes, here I mimic my wanted bahavior by scaling “Target_Pivot” with “Source” as its child, but I’d like to be able to script scaling “Source” in relation to “Target_Pivot” regardless of their hierarchy):
… but it does so in relation to source_prim_to_scale’s internal pivot (so it scales the “Source” mesh from it’s central pivot, on both ends), not the external target_pivot_to_scale_to on just one end.
@mzaras if you were to establish a parent/child hierarchy in such a way where the mesh prim is the child of the xform (you can do so via dragging and dropping the mesh prim onto the xform inside of the Stage panel), you would then be able to scale the xform to produce the result you are looking for.
and, just to think out loud - anther way to accomplish this without this hierarchy is to utilize the Pivot Tool and modify the pivot:
Hi @Simplychenable, thanks for your reply. I’m trying to avoid dependence on hierarchy and I’m scripting in python instead of using UI, but your link gave me an idea:
When I try to replicate it using a script however, Translate:pivot seemingly gets added just the same, but it doesn’t actually translate the cube’s pivot, but the cube itself (it acts as another Translate):
import omni.usd
from pxr import Gf, Sdf, UsdGeom, Usd
stage = omni.usd.get_context().get_stage()
time = Usd.TimeCode.Default()
# * Gets Source cube's matrix and translation
source_prim_to_scale = stage.GetPrimAtPath("/Source")
source_xformable = UsdGeom.Xformable(source_prim_to_scale)
source_local_matrix = source_xformable.GetLocalTransformation()
# # * Gets Target Pivot's matrix and trnaslation
target_pivot_to_scale_to = stage.GetPrimAtPath("/Target_Pivot")
target_xformable = UsdGeom.Xformable(target_pivot_to_scale_to)
target_pivot_local_matrix = target_xformable.GetLocalTransformation()
source_xformable.AddXformOp(UsdGeom.XformOp.TypeTranslate, UsdGeom.XformOp.PrecisionDouble, "pivot")
# here I'm changing the xformOpOrder bc to mimic "xformOp:translate:pivot" getting added right after "xformOp:translate" in xformOpOrder if I add it manually but it doesn't do anything in the end
new_xformop_order = [UsdGeom.XformOp(source_prim_to_scale.GetAttribute("xformOp:translate")),
UsdGeom.XformOp(source_prim_to_scale.GetAttribute("xformOp:translate:pivot")),
UsdGeom.XformOp(source_prim_to_scale.GetAttribute("xformOp:rotateXYZ")),
UsdGeom.XformOp(source_prim_to_scale.GetAttribute("xformOp:scale"))]
source_xformable.SetXformOpOrder(new_xformop_order)
the “isInverseOp=True” inverts the transformation of translate:pivot done to the mesh itself, leaving the transformation done to the pivot itself.
Here’s the python script to add xformOp:translate:pivot to a mesh and moving it to external prim’s pivot location so that the mesh can scale in relation to that pivot, not to its default center pivot:
