Creating Animation for Video Games
Creating animation for video games has become reliant on motion capture, but SPINE developer Nekki has gone further than most, having created its own app, called Cascadeur. This adds to a workflow that includes Unreal Engine 5 and Epic Game’s MetaHuman, but one that doesn’t always rely on those ‘off the shelf’ apps for its stylized anime-like animation.
SPINE’s Lead Animator Talks Performance Capture
In our developer series on upcoming gun-fu game SPINE, we’ve already discovered how Nekki is creating a new ‘intelligent’ action camera as well as why the game’s art director loves using Unreal Engine 5, but here I chat to the game’s lead animator, Evgeniy Khapugin, and discover how performance capture is being used for the game’s fluid, athletic combat.
Challenges of Integrating Motion Capture
The biggest challenge for us is the leap in animation quality, which demands more complex and polished rigs. For comparison, in our previous projects, we had strict limits on the number of joints. In our mobile project Shadow Fight 4: Arena, we used 91 joints, 58 of which were facial. Now, developing for PC and consoles, we no longer have such hardware limitations and have increased the number of joints significantly. Our main character currently has 1,217 joints, 839 of which are facial.
Tools and Approaches for Mocap Data
We use every motion capture tool we can get our hands on! Mocap is a convenient tool that allows us to quickly see results. By the final stages, there may be little to none of the original mocap left, but it lays a strong foundation. Mocap also helps us determine whether something needs to be changed or completely redone.
We also work with external mocap studios using classic optical marker systems, specifically Vicon in our case. There, we capture movements that our team can’t perform – complex falls with rolls, parkour and stunt work, fight choreography, paired combat interactions and interactions involving props.
Unbaking and Animation Refining
Cascadeur has evolved into a standalone product, driven by both internal and external user requests for mocap tools. One such tool is ‘animation unbaking’, which simplifies the process of working with motion capture. This tool functions somewhat similarly to the Simplify Curve filter in Maya, but it’s more advanced.
With internal algorithms, Cascadeur identifies keyframes and retains only those, preserving the overall motion while reducing the number of frames. This makes it easier for animators to edit. After ‘unbaking’, we can work on retiming to make movements sharper. Then, we can apply auto-physics to correct any inaccuracies, and finally, refine amplitudes, arcs, action lines, and so on.
Balance Between Raw Data and Style
In SPINE, we have two types of animation tasks: gameplay animations and cutscene / acting animations. Let’s start with gameplay animations. In gameplay, the most important aspect is how the animation feels and plays in the game, and only then how it looks. If you view these animations outside of the game, they may not look as physically accurate as if they were in a cutscene.
When the player presses a button, they expect an immediate response, and the animation needs to provide that feedback. Raw motion capture data is useful in the early stages, just adjusting the timing and distances. We insert it roughly, without fine-tuning. The focus here is speed and iteration. Playing these rough animations with the game designer helps us figure out the direction.
Unreal Engine 5 and Procedural Animations
We don’t use Unreal Engine 5 during the mocap process. When working with Vicon, we use MotionBuilder to view the character immediately, while for Xsens, we rely on their native software without retargeting. In our animation pipeline, we try to avoid using Unreal for animations. Not because Unreal is bad, but because it’s important for us to have a single source of animation software.
In Unreal Engine 5, we handle procedural animations. For example, our robotic spiders walk procedurally. They have six legs, climb walls and floors, and their legs automatically find where to step and react accordingly.
Conclusion
Nekki’s use of motion capture and custom software, such as Cascadeur, has allowed for a high level of detail and realism in the animation process for SPINE. By combining these tools with Unreal Engine 5, the team has been able to create a unique and engaging gaming experience.
FAQs
Q: How does Nekki approach the animation process for SPINE?
A: Nekki uses a combination of motion capture, custom software, and Unreal Engine 5 to create high-quality animations for SPINE. The team focuses on capturing realistic movements and then stylizes them to fit the game’s aesthetic and gameplay requirements.
Q: What is Cascadeur and how does it aid the animation process?
A: Cascadeur is a custom software developed by Nekki for motion capture and animation processing. It allows for animation unbaking, retiming, and auto-physics, making it easier to refine and adjust animations.
Q: How does Nekki balance the need for realism and stylization in animation?
A: Nekki approaches animation as a two-step process, first capturing realistic movements with motion capture and then stylizing them to fit the game’s aesthetic and gameplay requirements. The team also adjusts timing and distances to make the animations feel more dynamic and engaging.
