The Avengers: Age of Ultron

For the Avengers: Age of Ultron, Australia’s Animal Logic was tasked with shots that leaned towards the visually abstract. From the VFX for the JARVIS hologram, the Ultron hologram, and a trip into cyberspace, they were faced with open-ended requests that would require experimentation and creative vision.

Given the broad range of visual possibilities, Animal Logic spent much of the initial production stages experimenting with hundreds of iterations, working alongside the client to narrow down exactly how to visually communicate the director’s ideas and how to fit them into the context of the story. 

“Having a procedural workflow is essential for this kind of complex design work - it's important not just for the final product, but for all experimentation along the way” says Matt Ebb, Digital Artist at Animal Logic. “Because we were working with such an open ended brief, Houdini acted as our digital sketchpad, letting us easily experiment with different ideas and techniques that could be easily re-purposed later down the line”.

"Houdini acted as our digital sketchpad, letting us easily experiment with different ideas and techniques that could be easily re-purposed later down the line."

Throughout the project, Animal Logic were creating not just a look at a particular snapshot in time, but a constantly evolving and moving holographic system, and the best way to capture and present it was by building it in 3D. 

Their shots required them to visualize intelligent holographic systems with a sense of deep complexity, action and reaction, and energy transfer. Houdini's procedural workflow gave them a solution they could use to drive the effect’s animation with audio signals and have segments react in accordance to the animation of surrounding geometry. With this procedural workflow came the occasional random event which proved perfect for the shot.

Most of their work creating the JARVIS hologram, the Ultron hologram and complete CG shots of Cyberspace was accomplished using Houdini to procedurally model, animate, light, and render. It was critical that they worked as efficiently as possible without losing time running simulations. 

“Our setups were designed to be as 'live' and interactive as possible, without simulation or baking out data, which is a great way to experiment,” explains Matt. “A good non-destructive procedural workflow lets you get in and tinker at any point along the node network, and see the results immediately, providing much needed fast creative feedback, which easily gets lost if you're waiting for heavy simulations on the farm”.

Animal Logic employed a wide range of Houdini geometry features including volumes, point clouds, curves, and a very liberal use of Volumes (VOPs) and VEX wrangle Surfaces (SOPs).

The integration of Animal Logic’s proprietary asset system and pipeline into Houdini relies heavily on digital assets. External assets are imported in a procedural manner which allows their Houdini artists to visualise and edit the presentation of assets such as props and sets. 

Because of its tight integration and flexibility in Houdini, Animal Logic chose Mantra to render all of their shots in The Avengers: Age of Ultron.

“Being able to very easily generate custom attributes on geometry and have it flow through simply and quickly through to your shader, or continuing through as AOVs for comp is a huge time saver,” says Matt. “The ease of exporting AOVs per-light and per-component is great too. In situations such as this, it’s not just a matter of an incremental improvement in time taken - in other more rigid pipelines, even if it’s possible to make small changes like this, they’re often so cumbersome that they’re more trouble than they're worth. Having that accessibility and integration makes things possible in the sense that it’s not going to waste half your day to do small experiments.”

Houdini’s procedural workflow provided artists at Animal Logic with a clear benefit in this project as it enabled them to generate and evaluate a wide range of visual possibilities for the look of these effects, providing a means to easily share useful tools with colleagues, and complete their shots with Mantra.

“The interconnectedness of Houdini’s various components made it easy for us to work across all aspects of the design at a time,” says Matt. “We didn’t have to worry whether a client change could involve sending things back to other departments, we could do it all on the spot. When we were concentrating on getting variations on a certain look, we were able to use the most appropriate technique for the job whether it was done by generating attributes on the model, or coming up with shading tricks.”