The conference brought together several industry professionals, including Julien Margelin, Thomas Louisor and Antoine Vienne from CGEVVFX, Balthazar Sahel for MPC Paris, and Anthony Maalouf representing One of Us.
In Workflow In and Around Houdini: Beyond the Interface, Balthazar Sahel shared an in-depth look at the workflows developed at MPC Paris on Troll 2, in collaboration with One of Us.
The project offered a strong opportunity to put USD workflows and Solaris expertise to the test within Houdini. Beyond snowy environments, large-scale destruction and dynamic effects, the real challenge lay in integrating a giant troll across dozens of shots. Snow interaction, smoke, muscle and skin simulation, vegetation scattering and fur all had to work seamlessly together. None of these elements is particularly complex on its own, but combining them at scale, across a high volume of shots, significantly raised the level of complexity.
A key part of the approach was building a stable and efficient workflow between USD, SOPs and Solaris. After evaluating several options, the team adopted a pragmatic solution using the USD Import node in SOPs, which proved to be the most reliable in production. Simulation tasks were then distributed across a modular pipeline, allowing muscle, skin, vegetation and fur processes to interact smoothly. Carefully managed caching and iterative exchanges with Solaris ensured a consistent assembly of the final USD assets.
On the rendering side, assets were validated both in Karma for quick visual checks and in Arnold to guarantee compatibility before being handed over to lighting in Maya. While this pipeline is solid and well-structured, the talk emphasized that the real innovation lies not just within Houdini itself, but in how artists work around it.
One of the main focuses was knowledge sharing and tool evolution. Artists continuously develop scripts to improve their workflows, often in Python, and capturing this effort is essential. To support this, MPC Paris developed a centralized toolbox that allows artists to store, share and reuse scripts across projects and software. Tools created for specific tasks can gradually be adopted at a wider scale, evolving from individual use to production-wide and eventually studio-wide deployment.
Within Houdini, this philosophy translated into a flexible approach favoring the sharing of node graph templates rather than relying solely on more rigid HDAs. Using simple functions to save and reload node setups, artists were able to exchange fully editable graph structures, encouraging collaboration and rapid iteration. This approach was quickly embraced by the team.
Another key element presented was MikChain, an in-house batching and orchestration tool developed at MPC Paris. Acting as a layer above different software, it allows complex workflows to be chained and executed without manual intervention. On Troll 2, MikChain automated the entire process, from exporting animation in Maya to running simulations in Houdini, generating caches, producing check renders and publishing precomps in Nuke. This “batch-first” approach proved highly efficient. By processing large sets of shots overnight, teams could quickly identify problematic cases and focus their efforts where it mattered most. It is a straightforward concept, but extremely powerful at production scale.
Importantly, this thinking has extended beyond internal tools. Much of the logic developed in MikChain has since been integrated into Meshroom, MPC’s open source solution. Originally designed for photogrammetry, Meshroom is evolving into a broader pipeline tool capable of orchestrating complex workflows, including Houdini-based processes.
Interestingly, this marks a shift in how tools interact. Where Houdini once triggered Meshroom processes, Meshroom can now integrate and drive Houdini within a larger pipeline ecosystem.
Ultimately, the talk highlighted a key idea: while Houdini offers immense flexibility, its true power is unlocked through the way workflows are structured, automated and shared. Building strong systems around the software is what enables teams to scale efficiently and maintain creative control across complex productions.
