How can I change the color of an existing light with Python API

Omniverse Developer Tools & Resources Samples & Examples
1

Hello I have two questions

  1. “How can I change the color of an existing light in an Omniverse stage?”
  2. “How can I modify the color of an existing prim object in Omniverse?”

I wish to solve these tasks using the Python API. If possible, I’m curious about the sample code along with the libraries I need to import.
If you have experience solving this issue, please share it

2

For changing the light:

import omni.usd
from pxr import Gf, Usd

stage = omni.usd.get_context().get_stage()
prim = stage.GetPrimAtPath("/World/CylinderLight")
attr = prim.GetAttribute("inputs:color")
attr.Set(Gf.Vec3d(0.8, 0.5, 0.5))
# Optionally you can provide time to animate color
attr.Set(Gf.Vec3d(0.8, 0.5, 0.5), Usd.TimeCode(2))
3

import omni.usd
from pxr import Gf, Usd, UsdGeom
stage = omni.usd.get_context().get_stage()

for prim in stage.Traverse():
prim_name = prim.GetName()
if “Sphere” in prim_name or “light” in prim_name:
print(prim_name)
xform = UsdGeom.Xform(prim)
print(xform.GetPath())

prim = stage.GetPrimAtPath(“/World/NUC12_07/Geometry/cart_12/Sphere/SphereLight”)
attr = prim.GetAttribute(“inputs:color”)
attr.Set(Gf.Vec3d(0.8, 0.5, 0.5))

화면 캡처 2023-08-27 183415
화면 캡처 2023-08-27 1834151234×792 119 KB

"I understood the method. However, there seems to be an error with ‘light’. Could it be slightly different?

Also, I would appreciate it if you could tell me how to change the Material.

4

@inyong2327 you can examine the USD snippets on creating and modifying materials attributes like color:

what was the actual issue with the other script to change light color? the indentation?

5

Error in ‘pxrInternal_v0_20__pxrReserved__::UsdStage::_SetValueImpl’ at line 6028 in file C:\b\w\ca6c508eae419cf8\USD\pxr\usd\usd\stage.cpp : ‘Empty typeName for </World/NUC12_07/Geometry/cart_12/Sphere/SphereLight.inputs:color>’

I tried changing the color of the Light using the code you provided, but I encountered this error. It says there’s no attribute ‘.inputs:color’. Am I using it incorrectly?

and It would be helpful if you could also provide an API to reference which attributes are present in the prim object.

Thank you.

6

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