Choppy or unnatural motion typically results from unclear prompts, inappropriate duration settings, or extreme guidance scale values. First, ensure your prompt describes smooth, continuous actions rather than disconnected poses—write 'a person walks forward smoothly for five steps' instead of 'person standing, then walking, then stopping'. Second, verify your duration matches the action complexity; 12 actions crammed into 3 seconds will look rushed. Third, avoid guidance scales above 9, which can produce robotic, over-constrained movement. If the motion still feels stiff, try lowering guidance to 4-5 for more organic fluidity. Also check that you're viewing the FBX at the correct framerate in your 3D software (typically 30 or 60 fps). For comparison,
Hunyuan Motion Fast prioritizes speed over smoothness, so standard Hunyuan Motion generally produces more polished results for final production work.