Rather than explaining each of the solver settings here, head over to our recently recorded livestream: Motion Warping and Full-Body IK | Inside Unreal. In this video, we deep-dive into the inner workings of the solver and how it is used on The Ancient One. At a high level, all we want to do is keep the feet planted and tweak the rest of the body to lean toward Echo, while reaching forward with the right hand. By adjusting some bone settings on the solver, we’re able to refine which bones can twist and move as the solver tries to reach the transforms we’ve provided.The last piece of this function is aiming the hand itself at the laser hit location, stored as the actor_transform control. Rather than relying on the solver to get the hand orientation just right, we let the solver do the rough posing pass and refine the pose after the solver’s finished. In this way, we use the solver for its strengths and maintain art-directability without a lot of frustration. For the Aim setup, we’re just identifying the Axis for the palm of the hand and providing the actor_transform as the target. 

Tell your stories

Animation is about telling a story and at Epic, we’re working hard to build tools for storytellers. We’re just now seeing what Sequencer can do with character animation, whether hand-keyed or with motion capture. With tools like Control Rig and Full-Body IK, combined with a runtime engine, the stories we tell will be more dynamic, immersive, and impactful. 

Although the character rig and runtime setup can be complex, by building in layers and compartmentalizing the logic, we were able to build a character that was easier to debug, more flexible and procedurally art-directable. Every part we built was designed to empower the artists and designers; Control Rig provided the dials and switches and was just one tool in a well-stocked toolbox. 

We go into more detail about the Full-Body IK solver and the graph implementation (along with my blunders along the way) in our recent Inside Unreal livestream

UE5 is still in Early Access, and rigging and animation are capabilities we’re dedicated to getting right. We welcome your feedback to help us make Unreal Engine 5 the best it can be. Join us on the forums or even ping me on Twitter.

To learn more about the Valley of the Ancient animation features, along with the rest of the amazing work that went into the project, you can read more in the guided tour in our Content and Samples page.

Additional Links:
Meerkat Sample Project
MetaHumans
Animating with Control Rig in 4.26 | Inside Unreal
Evolving Animating with Unreal Engine

Source: Unreal Engine Blog