DazToHue 1.2 - Using the animation retargeting nodes

A new set of animation retargeting nodes from release 1.2 is introduced as an experimental solution, still in early development and ripe for refinement. The narrative underscores their innovative potential, while acknowledging the current need for improvements. Upcoming Unreal Engine 5.4 is expected to incorporate built-in retargeting capabilities, which might render these experimental nodes redundant.

Animation retargeting requires aligning source and target skeletons using predetermined reference frames, such as a default rest pose and a T-pose. The process involves loading these retargeting poses in the software before introducing the animation clip, ensuring that the inverse kinematics solver works effectively. Once the reference frames are set, the animation is loaded and carefully calibrated, then exported as an FBX file with clear nomenclature linking it to its base figure type. This methodology mirrors techniques used in other engines, emphasizing consistency and fine-tuning for optimal results.

Seamless Integration of Animation Nodes Retargeting begins by placing Daz nodes using either the shelf tool or the network editor, then adjusting the node’s position as needed. Importing the proper skeleton node removes errors and restores the character while the system defaults to the standard range of motion. Animations are populated effortlessly by selecting FBX files, allowing for immediate preview and retargeting onto the character.

Adapting Animation to Varying Skeletons with IK Solver Direct transfer methods work accurately only when the source and target characters are an exact match. Transitioning to the IK solver method becomes essential when source animations, such as those from a Genesis 3 character, are applied to a different skeleton like Genesis 8.1. Loading default bone mappings aligns the differing skeletal structures, ensuring the IK solver accurately retargets the animation without compromising the intended motion.

Accurate Retargeting through Skeleton Matching and Motion Extraction Ghosted mode unveils the underlying skeleton, displaying the source avatar on one side and the target animation on the other. Changing the source skeleton type and reloading default mappings ensures that animations, like the Genesis 9 run, are retargeted accurately onto the desired character. Consistency is maintained by allowing each retargeting node to work only with matching source animations, which may require deleting incompatible ones. Force motion options further refine the process by either extracting or retaining the root’s forward movement as needed.

Dynamic Integration of Roko and Mixo Nodes for Seamless Motion Capture Specialized nodes for Roko and Mixo animations are added via shelf tools, with the skeleton node dragged into the input field to set up the retargeting pipeline. The Roko node, using an IK solver, automatically handles motion and facial animation curves while previewing both the source and retargeted motions. Likewise, the Mixo node seamlessly imports motion capture data onto the character, with ghosted view and force motion options available. Both nodes illustrate a streamlined approach to synchronizing and transferring complex motion capture data.

Challenges with twist rotations arise from inconsistencies between DAZ and Mixamo skeleton structures, as the former includes a dedicated twist bone while the latter does not. Excessive twisting at the hands and elbows results from this mismatch, leading to anatomical inaccuracies in the animations. The solution involves redistributing the twist, transferring the bulk of the rotations to the twist bones for a more natural movement.

Roko and Miimo animations display an unnatural sideways bend in the pinky joint, creating an impression of a broken finger. The pinky, which should move within a constrained range, exhibits excessive and flawed flexibility inherent in the source material. This oversight in the original animation leads to the faulty behavior observed even in preliminary stages. Houdini tools provide potential corrective measures, though they only partially address the underlying source limitations.

Retargeting animations from Daz to UE5 requires using the unchanged UE5 mannequin skeleton instead of the modified Daz-compatible version. Changing the target from the native Daz skeleton to the UE5 mannequin alters the animation preview to display the true UE5 character. A balanced mix of brute-force adjustments and retention of original Daz bone orientations has emerged from extensive trial and error, given the sparse documentation on this process. Future revisions are anticipated as Epic Games refines UE5 compatibility in upcoming versions.

Unlocked animation retargeting nodes enable users to dive into network graphs for fine-tuning, separating concerns between data cleansing and IK solving. Within a safety zone marked by color-coding, a dedicated cleansing sub-network prepares motion capture data while an IK node maps only essential bones between source and target skeletons. Precise pose offset adjustments further refine the alignment of reference frames for both skeletons, ensuring accurate animation transfer.

Real-Time Pose Refinement Through Pinned View and Tweak Nodes A fixed viewport is enabled with a pin tool, allowing live visualization of changes as the animation is adjusted. The initial reference frame of the target skeleton is refined by tweaking joint orientations, such as a subtle Y rotation on the upper arm. Continuous scrubbing through the animation ensures adjustments maintain consistency without causing clipping.

Precision IK Solving and FK Transfer for Detailed Bone Mapping The IK solver provides full body retargeting between the source and target skeletons with a configuration that boosts the stability of critical bones like the feet. Boosting foot bone priority minimizes jitter and keeps them grounded. Mapping and FK transfer nodes are used for fingers and toes, ensuring these finer details are accurately transferred and aligned.

Animation retargeting nodes lack built-in export options, so the DustH export node handles the process by enabling the export retargeted animations option and accepting input from either a skeleton or an animation retargeting node. Specific animations, like a run G9 sequence, can be exported directly, while merging multiple retargeting nodes allows all animations to be exported in one consolidated step. This method yields a complete folder of animations, with six animations produced in nearly 4½ minutes, though performance improvements are anticipated in future updates.

The Victoria 8.1 test character was integrated into Unreal Engine alongside Houdini-exported animations, demonstrating the system's capacity for animation retargeting. A butterfly mixo animation and a roko motion capture sequence with facial capture were applied, highlighting the effectiveness of current facial animation techniques despite incomplete blueprint setups. Additionally, a Genesis 9 run animation was transferred to a Genesis 8.1 character with leave force enabled to ensure proper alignment, showcasing the functionality of the animation retargeting nodes in d Hue 1.2.