In section 1.1.14 of the Isaac Sim Tutorial the tutorial introduces the concept of parent-child relations between objects through the stage.
However, the instructions provided don’t seem to work. When the Cube is nested under the Xform and then I attempt to nest the Xform under the sphere I get the error:
Cannot move prim /World/Xform to /World/Sphere/Xform as nested gprims are not supported
@david.hall2 i am just another user passing by - interestingly this wasn’t a problem in 2022.2.1, but i can confirm getting the same result in 2023.1.0. perhaps we can wait for the mods/devs to confirm whether it’s incorrect instruction from the doc side, unintended behavior/bug, or there’s something we overlooked.
my understanding that in OpenUSD, Geometries cannot be parented under other geometries and will require an xform prim. however, it certainly seems odd that the error is thrown in this case.
to add, when comparing the xforms in the two versions mentioned, 2023.1.0 seems to have an added ‘geometry’ attribute, which could be the reason behind why the xform is behaving weirdly, but i am simply speculating:
It seems that shapes and meshes cannot have shapes, meshes, or xforms nested underneath them. XForms can have shapes, meshes, and XForms underneath them.
The error message could definitely be more intuitive since when using Isaac Sim you never interact with something called a GPrim.
here are the two versions with the same operation (cone and cubes are both shapes):
2023.1.0 -
2022.2.1 -
@dan.sandberg you are correct in that geom can’t be nested under geom; but, 2023.1.0 seems to exhibit unexpected behavior as we are trying to nest an xform prim under geom, which shouldn’t pose any issue…on paper. again, this is only my observation, so mods/devs feedback may be needed here.
Oh, sorry, my mistake, thanks for the correction. I wonder if they generalized things in 2023.1.0 so that Shapes & Meshes had to always be “leafs” in the graph.
I"m encountering the same issue in 2023.1.0.
I will just note here that this issue also occurs for the tutorial on adding cameras to robots. You are unable to add a camera to the robot “body” as nested gprims are not supported.
Tutorial or functionality needs update.
I don’t know if this can help, but I noticed that it’s possible to nest shapes to xforms, and nest xforms with shapes inside to other xforms:
Nesting meshes is no longer possible in the latest release. Documentation will be updated soon!
Thanks all for the responses :) good to know there will be updates to the documentation and that xforms seem to be the way to go
I encountered the same issue (nested gprisms are not supported) of adding cameras to robots . So may I know what should be the way to attach camera to robot?
I found that you can right click on the body (in stage) and choose Create>Camera
thank you! Solved
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