# Importing USD that only has an animated skeleton causes error **URL:** \ **Category:** Pipeline & Plugins\ **Tags:** Importing, unreal-engine, import, bug-report, question, USD\ **Created:** [February 10, 2024, 2:00am UTC](https://forums.unrealengine.com/t/importing-usd-that-only-has-an-animated-skeleton-causes-error/1677781 "2024-02-10T02:00:56Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![FrozenDK-1](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@FrozenDK-1](https://forums.unrealengine.com/u/FrozenDK-1)\ **Post date:** [February 10, 2024, 2:00am UTC](https://forums.unrealengine.com/t/importing-usd-that-only-has-an-animated-skeleton-causes-error/1677781/1 "2024-02-10T02:00:56Z")
When I tried importing a USD file with the USD Import plug-in I got this error message and logs. ![image](https://d3kjluh73b9h9o.cloudfront.net/original/4X/4/a/e/4ae525ca5b80926d99063ecb0ddbc3b8ecb2777c.png) ![image](https://d3kjluh73b9h9o.cloudfront.net/original/4X/f/9/5/f951324cfd51ca8599c71322432ade5370517889.png) The file only contains a skeleton with animation on it. I’ve been trying to replicate my regular FBX workflow by having a rigged character with the geometrical mesh in A/T-pose in one file and animated skeleton files with no geometry attached separately. I’ve been able to to get the rig file to work as it should, but the animation files are not working without attaching the geometrical mesh to the files. Are there any solutions to this issue? Also, I noticed that “Use Motion from Skel Root” doesn’t always work. There are a few files I haven’t been able to import with this on (same error). Is it related to my first issue? ---
**Author:** ![FrozenDK-1](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@FrozenDK-1](https://forums.unrealengine.com/u/FrozenDK-1)\ **Post date:** [February 10, 2024, 2:17am UTC](https://forums.unrealengine.com/t/importing-usd-that-only-has-an-animated-skeleton-causes-error/1677781/2 "2024-02-10T02:17:19Z")
Oops, didn’t post the entire log for the error. Here’s the full one: ![image](https://d3kjluh73b9h9o.cloudfront.net/original/4X/8/3/2/832ea9906c84735a8ee1fc7e25dab69690a0582f.png) ---
**Author:** ![UE\_FlavienP](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/ue_flavienp/32/1194546_2.png) [@UE\_FlavienP](https://forums.unrealengine.com/u/UE_FlavienP)\ **Post date:** [February 12, 2024, 11:36am UTC](https://forums.unrealengine.com/t/importing-usd-that-only-has-an-animated-skeleton-causes-error/1677781/3 "2024-02-12T11:36:29Z")
Is the USD a file you could share with us? ---
**Author:** ![FrozenDK-1](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@FrozenDK-1](https://forums.unrealengine.com/u/FrozenDK-1)\ **Post date:** [February 21, 2024, 3:40pm UTC](https://forums.unrealengine.com/t/importing-usd-that-only-has-an-animated-skeleton-causes-error/1677781/4 "2024-02-21T15:40:00Z")
Sorry for the late reply. Here are the files that I exported out of Blender. [TestDroid\_Anim\_Wave.usdc](https://forums.unrealengine.com/uploads/short-url/6hmHxe44puZBLPoAN5GMSM3eYeS.usdc) (33.0 KB) [Rig\_TestDroid.usdc](https://forums.unrealengine.com/uploads/short-url/xYRvM6k02hNkMIMx1jdGTNueXXH.usdc) (39.5 KB) Here are the .blend-files to try exporting as USD as well in case of it being a Blender specific issue. Need to use Blender 4.1+, since the devs recently added new animation export options for USD. [Rig\_TestDroid.blend](https://forums.unrealengine.com/uploads/short-url/301tM0AljrFAHZGi5hkhjdjmurU.blend) (190.5 KB) [Anim\_00\_TestDroid\_Wave.blend](https://forums.unrealengine.com/uploads/short-url/nuGUEqS4CU8kiHUhrcn74c7ZzlI.blend) (185.1 KB) ---
**Author:** ![UE\_FlavienP](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/ue_flavienp/32/1194546_2.png) [@UE\_FlavienP](https://forums.unrealengine.com/u/UE_FlavienP)\ **Post date:** [February 21, 2024, 4:48pm UTC](https://forums.unrealengine.com/t/importing-usd-that-only-has-an-animated-skeleton-causes-error/1677781/5 "2024-02-21T16:48:53Z")
Okay, so USD import dialog does not support the same workflow you are used to with FBX yet. You cannot import a file with only an animation as you cannot specify the skeleton to be used in the import settings. It is probably going against your workflow but you can try to create a new USD stage in which you compose the skeleton with the animation. So either you change your blender export workflow to export animation with skeleton or you have to compose the two together in a new stage. e.g.: I did it in Unreal - create an empty stage - add Rig\_TestDroid.usdc as a reference on the root - add TestDroid\_Anim\_Wave.usdc as a second reference on the root Now I can import all at once. ![image](https://d3kjluh73b9h9o.cloudfront.net/original/4X/0/d/6/0d615c50a5e477bb294c51c4ea72c41f4d064272.png) ---
**Author:** ![FrozenDK-1](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@FrozenDK-1](https://forums.unrealengine.com/u/FrozenDK-1)\ **Post date:** [February 21, 2024, 11:04pm UTC](https://forums.unrealengine.com/t/importing-usd-that-only-has-an-animated-skeleton-causes-error/1677781/6 "2024-02-21T23:04:18Z")
Thank you for your assistance! Yeah, I was afraid of that. Thanks for confirming it! I just tried your method and it works. Going to take a bit of getting used to. Thanks for the tip! 🙂 A follow up question I have is if it is possible to merge multiple animation files besides that wave animation into the same file? Can multiple USD files be merged to the root at once, or must I use the Root method for each file? Also, is there a way to retain the name of the animation when being referenced? When I merged it the name became this instead: ![image](https://d3kjluh73b9h9o.cloudfront.net/original/4X/f/4/9/f49fccd9df75e6b97ff6ff35b1ddfc5168b99798.png) ---
**Author:** ![system](https://d3kjluh73b9h9o.cloudfront.net/original/4X/7/1/3/713c9d3f58553f0de89543d76a8a3a2779dc9fa4.png) [@system](https://forums.unrealengine.com/u/system)\ **Post date:** [March 22, 2024, 11:04pm UTC](https://forums.unrealengine.com/t/importing-usd-that-only-has-an-animated-skeleton-causes-error/1677781/7 "2024-03-22T23:04:42Z")
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