Hello Epic Games Team,
We are currently developing an Action RPG using Unreal Engine 5 and have implemented Motion Matching as the core of our character animation system.
We have a question regarding our skeletal mesh import workflow.
As we understand it, Unreal Engine 5 applies a default rotation of -90 degrees on the X-axis to the transform of imported skeletal meshes. This is done to compensate for the coordinate system differences between UE5 and various DCC tools.
For development convenience, our team prefers to maintain a clean base rotation of (Roll=0, Pitch=0, Yaw=0) for skeletal meshes in the editor. To achieve this, we are considering a workflow where we pre-rotate the entire skeleton hierarchy, including the Root joint, by +90 degrees on the X-axis within the DCC tool before exporting. This approach ensures that the imported asset has a rotation value of (0, 0, 0) in the Unreal editor.
While we expect this method to improve intuitive usability in the editor, we are concerned about potential issues it might cause, especially concerning our Motion Matching system.
Our specific questions are as follows:
Could this workflow of pre-rotating assets in a DCC tool to counteract the engine’s default rotation affect the accuracy of the trajectory and pose data that our Motion Matching system relies on?
We would like to know if this workflow could lead to unforeseen side effects when interacting with systems like Root Motion, Animation Retargeting, and Inverse Kinematics (IK), due to the joint’s local axes differing from the standard convention.
Ultimately, could this non-standard approach lead to a degradation in the matching quality of our Motion Matching system or result in unpredictable character movement at runtime?
Could this workflow impact engine performance or cause compatibility issues with future Unreal Engine updates?
We would like to receive official guidance on whether our proposed workflow significantly deviates from Unreal Engine’s recommended pipeline, and whether this approach is discouraged, especially in an environment using advanced animation systems like Motion Matching.
Thank you for your time and assistance.