Hey,
I am trying to add new animations to the characters in Isaac Sim. The problem is when I import a Mixamo character, when I attempt to re target the skeleton, it causes a crash of the entire program. The crash logs just indication a segmentation fault error. For example Render People I can perform the retargetting, so the extension seems to work, but the format of the skeleton perhaps is causing the crash. I have viewed a Youtube tutorial on this (Video), and it seems to work but it is older version of Issac.
Could someone give some feedback on this? Thanks
Same here, tried with Isaac Sim Versions 5.1.0, 5.0.0 and 4.5.0 all result in a crash when trying to retarget animations for mixamo characters
Saw these warnings before the crash:
2025-11-13T10:07:03Z [76,667ms] [Warning] [omni.hydra] Mesh '/World/passive_marker_man/mixamorig_Hips/MocapGuy_Body' update topology/point without updating normal, fallback to smooth normal.
2025-11-13T10:07:17Z [90,582ms] [Warning] [omni.anim.retarget.ui.scripts.retarget_window] Retarget Warning: Root translation should be identity (/World/passive_marker_man/mixamorig_Hips/Skeleton) [(3.299752791008359e-9, 0.963756103515625, -0.0003547439351677895)]
And this is what Ive found in /root/.local/share/ov/data/Kit/Isaac-Sim Full/4.5/032a92ba-8b8f-4c11-93d2f390-9cf45aef.py.txt
Process 105715: ./kit/kit ./apps/isaacsim.exp.full.kit --ext-folder ./apps
Python v3.10.15 (/root/isaac-sim-450/isaac-sim-standalone-4.5.0-linux-x86_64/kit/kit)
Thread 0x7AFFBE339B80 (active+gil): “MainThread”
auto_setup (/root/isaac-sim-450/isaac-sim-standalone-4.5.0-linux-x86_64/extscache/omni.anim.retarget.core-106.5.1+106.5.0.lx64.r.cp310/omni/anim/retarget/core/scripts/rig.py:676)
_auto_setup (/root/isaac-sim-450/isaac-sim-standalone-4.5.0-linux-x86_64/extscache/omni.anim.retarget.ui-106.5.2+106.5.0/omni/anim/retarget/ui/scripts/retarget_window.py:282)
_on_select_skeleton_prim (/root/isaac-sim-450/isaac-sim-standalone-4.5.0-linux-x86_64/extscache/omni.anim.retarget.ui-106.5.2+106.5.0/omni/anim/retarget/ui/scripts/retarget_window.py:221)
_current_index_changed (/root/isaac-sim-450/isaac-sim-standalone-4.5.0-linux-x86_64/extscache/omni.anim.retarget.ui-106.5.2+106.5.0/omni/anim/retarget/ui/scripts/skel_selection_combo.py:209)
Thread 0x7AFD5D1FF6C0 (active): “ThreadPoolExecutor-0_0”
_worker (/root/isaac-sim-450/isaac-sim-standalone-4.5.0-linux-x86_64/kit/python/lib/python3.10/concurrent/futures/thread.py:81)
run (/root/isaac-sim-450/isaac-sim-standalone-4.5.0-linux-x86_64/kit/python/lib/python3.10/threading.py:953)
_bootstrap_inner (/root/isaac-sim-450/isaac-sim-standalone-4.5.0-linux-x86_64/kit/python/lib/python3.10/threading.py:1016)
_bootstrap (/root/isaac-sim-450/isaac-sim-standalone-4.5.0-linux-x86_64/kit/python/lib/python3.10/threading.py:973)
Thread 0x7AFD56FFF6C0 (active): “ThreadPoolExecutor-0_1”
_worker (/root/isaac-sim-450/isaac-sim-standalone-4.5.0-linux-x86_64/kit/python/lib/python3.10/concurrent/futures/thread.py:81)
run (/root/isaac-sim-450/isaac-sim-standalone-4.5.0-linux-x86_64/kit/python/lib/python3.10/threading.py:953)
_bootstrap_inner (/root/isaac-sim-450/isaac-sim-standalone-4.5.0-linux-x86_64/kit/python/lib/python3.10/threading.py:1016)
_bootstrap (/root/isaac-sim-450/isaac-sim-standalone-4.5.0-linux-x86_64/kit/python/lib/python3.10/threading.py:973)
Thread 0x7AFC047FF6C0 (active): “ThreadPoolExecutor-0_2”
_worker (/root/isaac-sim-450/isaac-sim-standalone-4.5.0-linux-x86_64/kit/python/lib/python3.10/concurrent/futures/thread.py:81)
run (/root/isaac-sim-450/isaac-sim-standalone-4.5.0-linux-x86_64/kit/python/lib/python3.10/threading.py:953)
_bootstrap_inner (/root/isaac-sim-450/isaac-sim-standalone-4.5.0-linux-x86_64/kit/python/lib/python3.10/threading.py:1016)
_bootstrap (/root/isaac-sim-450/isaac-sim-standalone-4.5.0-linux-x86_64/kit/python/lib/python3.10/threading.py:973)
Thread 0x7AFC03FFE6C0 (active): “ThreadPoolExecutor-0_3”
_worker (/root/isaac-sim-450/isaac-sim-standalone-4.5.0-linux-x86_64/kit/python/lib/python3.10/concurrent/futures/thread.py:81)
run (/root/isaac-sim-450/isaac-sim-standalone-4.5.0-linux-x86_64/kit/python/lib/python3.10/threading.py:953)
_bootstrap_inner (/root/isaac-sim-450/isaac-sim-standalone-4.5.0-linux-x86_64/kit/python/lib/python3.10/threading.py:1016)
_bootstrap (/root/isaac-sim-450/isaac-sim-standalone-4.5.0-linux-x86_64/kit/python/lib/python3.10/threading.py:973)
Thread 0x7AEF0CF106C0 (active): “asyncio_0”
_worker (/root/isaac-sim-450/isaac-sim-standalone-4.5.0-linux-x86_64/kit/python/lib/python3.10/concurrent/futures/thread.py:81)
run (/root/isaac-sim-450/isaac-sim-standalone-4.5.0-linux-x86_64/kit/python/lib/python3.10/threading.py:953)
_bootstrap_inner (/root/isaac-sim-450/isaac-sim-standalone-4.5.0-linux-x86_64/kit/python/lib/python3.10/threading.py:1016)
_bootstrap (/root/isaac-sim-450/isaac-sim-standalone-4.5.0-linux-x86_64/kit/python/lib/python3.10/threading.py:973)
Thread 0x7AEEFD7FF6C0 (active): “asyncio_1”
_worker (/root/isaac-sim-450/isaac-sim-standalone-4.5.0-linux-x86_64/kit/python/lib/python3.10/concurrent/futures/thread.py:81)
run (/root/isaac-sim-450/isaac-sim-standalone-4.5.0-linux-x86_64/kit/python/lib/python3.10/threading.py:953)
_bootstrap_inner (/root/isaac-sim-450/isaac-sim-standalone-4.5.0-linux-x86_64/kit/python/lib/python3.10/threading.py:1016)
_bootstrap (/root/isaac-sim-450/isaac-sim-standalone-4.5.0-linux-x86_64/kit/python/lib/python3.10/threading.py:973)
Ok, solved the issue.
Mixamo ships their characters without a root bone. They usually start with “mixamorig_Hips“ (when you look at omniverse characters, they all have a root bone). I just added a root bone in blender following this Video (https://www.youtube.com/watch?v=byghgoZW5ek&t=1s), then Animation Retargeting works.
That’s great. I have not tried that method but do add for others, I have resorted to using Mesh2Motion animations/characters and it works great as well. Thanks for the help.
good tip, thanks for sharing!