In this episode of the fxpodcast, we speak with David Schneider from Union VFX about one of the most interesting new production workflows to emerge around Gaussian splatting: using splats not simply as a visualisation technique, but as a practical crowd solution for feature film production.
Union VFX has been developing the approach in partnership with Clear Angle Studios, building on Clear Angle’s new Volumetric Capture Rig, or VCR. The rig uses 40 synchronised machine-learning cameras in a half-dome configuration, with integrated LED lighting, allowing performers to be captured under highly controlled, neutral lighting conditions. From those captures, Union can generate animated 4D Gaussian splats that retain a strong sense of photographic realism while being deployable inside a conventional VFX pipeline.
The key breakthrough is not just capture quality, but control. Gaussian splats are often admired for their realism, but they also present major production challenges, especially around temporal stability, segmentation, mattes, and relighting. In the podcast, Schneider explains how Union and Clear Angle have built a pipeline that allows the splats to be relit inside CG scenes using production lighting, cast and receive shadows, and be treated by compositors much more like traditional CG assets.
For crowd work, this is especially significant. Traditional CG crowds require modelling, rigging, animation, agent systems, and extensive variation work. Card-based crowds can be efficient, but they quickly fall apart when lighting or camera movement changes. Union’s approach sits somewhere new: captured real human performances, processed as splats, instanced into large-scale environments, and then relit and art-directed shot by shot.
Schneider discusses how machine-learning-based image segmentation allows Union to identify and isolate elements such as shirts, jackets, trousers, hair, and skin. Those regions can then be turned into Cryptomattes, giving compositors familiar controls for colour variation and shot finishing. That means a crowd can be populated with captured humans, while still allowing the team to vary clothing, adjust balance, and prevent obvious repetition.
The conversation also explores how close these splat-based characters can come to camera. Rather than being limited to distant background use, Union has tested characters at close to three-quarters screen height and found that, with correct relighting, they can hold up far closer than many traditional CG crowd solutions. For supervisors used to hiding crowd work behind foreground extras, smoke, atmosphere, or layers of photographic cards, this opens up a very different set of creative possibilities.
A major part of our discussion focuses on Clear Angle’s capture system (we have more on this in an upcoming story). The VCR is designed for high-quality 4D capture in a volume of roughly three metres by three metres by three metres. Depending on the requirement, Union can capture individuals separately for later instancing, or capture small groups interacting with each other, to add more natural crowd behaviours such as cheering, dancing, pushing, or laughing. These interactive group captures can then be sprinkled through larger crowds to avoid the mechanical feel that sometimes affects digital crowd systems.
Schneider also escribes a test involving a cyclist captured on static rollers, then moved through a CG environment as if traveling at speed. The same logic could apply to other kinds of performance capture: flying superheroes, wire work, stunt actions, or other cases where a production may not need a fully traditional digi-double, but still wants a highly realistic, controllable, relightable human performance.
While generative AI can create impressive short clips, it remains difficult to direct, repeat, extend, and control with the precision required for production. By contrast, Union’s splat workflow is based on captured performance and deterministic processing. The director and VFX supervisor can make specific decisions about where people go, how they behave, how they are lit, and how they are varied. In production terms, that control is everything.
Schneider also explains Union’s Nuke-based workflow for fast editorial turnover. After capture, Clear Angle can deliver sprite-like views from the rig, which Union can place into work-in-progress CG environments using a USD-based workflow. This allows supervisors and directors to make early layout and behaviour decisions using elements that correspond directly to the final splat captures. Once approved, that metadata can be passed downstream for full processing.
Rather than treating splats as a research demo or a visual novelty, Union VFX and Clear Angle are showing how the technology can be engineered into a practical, controllable, film-ready pipeline. Listen to the full fxpodcast as David Schneider explains how this new approach may reshape the way productions think about digital humans and crowd work, with captured GS performances.