Houdini's Magical, Innovative Touch

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Rhythm & Hues used Houdini to create Daredevil's Shadow World. All Daredevil images © 2003 FOX DAREDEVIL. Character Likeness: TM © 2003 Marvel Characters, Inc. Images Courtesy Rhythm & Hues [1]

The very mention of Harry Houdini's name conjures up images of magic and wizardry, but for some reason, the great master preferred to be known as an escape artist. Perhaps it was just to distinguish himself from those he considered to be the hacks and amateurs working during his day. The distinction may seem narcissistic, but maybe Houdini wanted us to distinguish the skill and precision of an escape artist from the fantasy world that magic encompasses. A magician's success is partly due to a viewer's ability to suspend disbelief. We believe because we think the performer has a magic touch, a gift to reach into the unknown. An escape artist however, wins over his audience because he has studied and practiced his artform to the nth degree and has logically figured out every angle on how to escape detection.

So it is with the software Houdini. Leading VFX artists depend on Houdini for modeling, rendering and animation. Moreover, they are impressed by its ability to mesh with other software so that the artist has the freedom to easily create innovative images. VFXWorld interviewed supervisors from three top houses on why they think Houdini is an indispensable tool for them. It's not hard to figure out that Houdini's success lies in how its software allows artists to create seamless images that defy imagination and, yes, even escape detection.

Caleb Howard, Digital FX Supervisor for Rhythm & Hues
At Rhythm & Hues [2], we have embraced Side Effects Software’s [3] Houdini across a number of departments for recent and forthcoming film projects, ranging from X-Men 2 [4] and Gigli. The open, modular nature of Houdini allows us to take full advantage of the application’s power within our pipeline, and it’s very easy for our in-house software team to encapsulate our innovations within or alongside the Houdini open architecture.

For our recent work on Daredevil [5], a movie about a man who lives without fear, but also without sight, we used Houdini in tandem with custom software to create systems for volumetric effects, lighting and wrinkling control for the title character’s leather suit. Thirty of our shots were created using Houdini to represent Daredevil’s “Shadow World,” which required unique visual effects to show how super-heightened senses of sound and smell steer Daredevil through a vision-less existence.

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Houdini's wrinkling technology helped make all of Daredevil's physical moves more realistic. [6]

Our team worked closely with the director, Mark Steven Johnson, and the art directors to create volumetric effects such as spheres of light that depict essentially non-visual phenomena — for example, Daredevil’s acquisition of amplified hearing. Similar effects were developed to support other “Shadow World” scenes, such as one in which the sightless superhero navigates a crowded ballroom by smell only.

To light all of our effects shots, we built a “plug-and-play” HDR (High Dynamic Range) lighting system around Houdini and our "Voodoo" software. This custom lighting model enabled multiple exposures from a digital camera to be taken and turned into a series of lights. Also for Daredevil, we developed a third Houdini pipeline that provided wrinkling technology. Each time we needed convincing CG effects when Daredevil flexes, we would take the animation, extract stretch-and-squash and key in different displacements using Houdini for the final rendering pass.

On this show and others, we’ve found that Houdini adds value by giving us more effective ways to meet visual effects challenges — challenges that in other software packages might not have been solved in an efficient timeframe, or at all. Houdini also helps us be more innovative because our in-house programmers can use the program as a foundation for implementing leading-edge custom tools. The software is straightforward and integrates well with popular file formats for geometry and animation. Other 3D packages, meanwhile, are just now working backwards to try to achieve the modularity and openness that has existed so elegantly in Houdini for years.

Another exciting thing about Houdini is that it now encompasses industry-leading toolsets not only for effects, lighting and rendering, but also for modeling, character animation, and compositing via Houdini Halo. We’ve tested the deep rasters, tiling and other new compositing capabilities in the latest version, and are looking forward to all of the future jobs where Houdini can give us an advantage.

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A52 was able to create this realistic progression of paint peeling off a Nissan Maxima by using Houdini. All Nissan Maxima images courtesy of A52. [7]

Denis Gauthier CG Supervisor for A52
A52 [8] has a well-established history of commercial CGI and visual effects work for top agencies and directors. Each project our CGI team does requires a unique solution, and we always rely on Side Effects Software’s Houdini. Recently, Houdini helped us win and deliver a challenging spot for Nissan.

TBWAChiatDay’s storyboards showed the Nissan Maxima racing through the desert so fast that its paint completely peeled away. Fortunately for us, it became evident that the main challenge was to create a fantastic but “natural-looking” effect, with emphasis on clarifying the effect visually while enhancing the realism.

Together with our creative director and project visual effects supervisor Simon Brewster, we decided to create a “proof of concept” test. Using Nissan’s wireframe model, our CGI team (including myself, Westley Sarokin and Jeff Willette) used Houdini, 3D Equalizer, Chalice and RenderMan to create a completely CGI Maxima and light it to look like it was shot in a studio under Fisher Lights. Using a variety of visual tricks, including spinning the wheels and using Houdini Channel Operators (CHOPs) to create synthetic suspension travel and camera shake, the CGI car looked extremely realistic. In the end, everyone who saw the test assumed we had shot the car on a stage and added peeling paint effects. It sold our clients on the CGI approach and earned us the job.

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A52 created a "proof of concept" test to show the client that Houdini could be used successfully to create a CGI car. [9]

Once director Adrian Moat’s location footage was edited by Angus Wall at Rock Paper Scissors, our four-man (augmented by John Willette) team’s work began with Westley’s painstaking tracking process using 3DEqualizer. We imported Westley's data into Houdini and filtered it using CHOPs. Our polygonal model, courtesy of Meshwerks, Utah, was in some cases converted into subdivision surfaces in Houdini, and each scene was rendered in RenderMan.

We then animated the car and flying paint particles via an approach Jeff developed using the Houdini VEX language, which made UV coordinates align along aerodynamic flow lines. That allowed us to deform each body panel in UV space, and the virtual lines directed the peeling of the paint and controlled the flow as paint particles disintegrated.

We hand keyframed travelling mattes for each body panel to control the peeling effect. Controlling the entire process by hand at the head end allowed us to accommodate creative input. The flying paint flecks were created through Houdini's Particle Operators (POPs), with VEX being used again to handle birthing particles on the paint surfaces’ leading edges. We also incorporated many effects elements Adrian Moat shot to make the CG more convincing and tactile.

This project is a great example of a trend we are seeing across the industry, in which ad agencies and production companies are becoming extremely sophisticated in how to use CGI effects to best advantage.

Based on the strength of our team and the sum total of the tools at our disposal, including Houdini, we're ready to create any visual challenge our clients can imagine.

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Houdini allowed CAMF Prods. to manage details efficiently in multiple platforms for the game Roman Race 6004 A.D. All Roman Race 6004 images courtesy of CAMF Prods. [10]

Michael Fuchs, Manager of CAMF Prods.
CAMF Prods. is a Salzburg, Austria-based studio focused on 3D computer animation and visualization for film, games, entertainment and other applications. Over the course of 10 years, Side Effects Software’s Houdini has been one of our key software applications. Most recently, we used Houdini to create highly detailed characters and landscapes for a new Xbox and PC game called Roman Race 6004 A.D. The 3D part of the game, in which teams of fantastical animals and riders are raced through ever-changing terrains, was modeled, textured and animated completely with Houdini.

One of the critical challenges for games development, especially when you are producing for multiple platforms, is to find an efficient means of managing detail. Sometimes a high-resolution version of a character or landscape is required, while in other places a lower-resolution version is more appropriate. Being able to adapt materials from high to low polygon count can significantly improve workflow and the manageability of project data overall.

Our solution to this was to work procedurally in Houdini, maximizing the software’s new polygonal character tools and VEX builder features to rapidly develop sets of 3D elements and effects that could easily be changed and displaced as needed. Working this way, our artists created high-resolution game-character models of about 8,000-9,000 polygons that could be brought down to 800-1,500 polygons with no perceivable loss in detail or distinguishing features. Each racing team was created in this fashion, enabling 3D elements to be maximized for use across different aspects of the game.

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Artist-friendly Houdini software allows animators to make changes quickly and easily. Here, Emu Atsu-Khan and Albedi Ohni fight to the finish in Roman Race 6004 A.D. [11]

The game’s landscapes were also generated procedurally in Houdini. This allowed complex changes to be implemented quickly and easily for the game engine during testing, and we could also apply them automatically for our “game floor” and the collision objects. At one level, we fully textured the landscape and optimized it for the game engine; at another, we adapted it for the cut scenes. At the game level, larger portions of the environment were cut into sections using Houdini surface operators (SOPs) in a technique that allowed us to determine on the fly how much of the landscape would be visible. For the cut sequences, custom procedural shaders were primarily used as a way to automatically assign different landscape attributes, such as sand deposits on the upper levels of a canyon or a “wet” (or darker) look to various sections of rock.

Throughout, such enhancements as an artist-friendly procedural interface for the Houdini VEX scripting language and Houdini VEX builder let us establish very efficient and flexible production techniques to create all of the 3D artwork and integrate it into the game engine. For this project, I think we were also among the first to use Houdini’s recently introduced enhanced character tools, particularly "Capture Paint," "Capture Mirror" and "Bone Mirror" within a games context. Overall, our use of Houdini on Roman Race 6004 A.D. allowed us to markedly improve our workflow, test more variations and ultimately deliver a more optimum game player experience.

An alumna of UCLA, Darlene Chan has worked in the motion picture industry for 14 years. She served as a production executive for Paramount Pictures, Walt Disney Pictures, Davis Entertainment and Motown. She produced Grumpy Old Men (1993) for Warner Bros. In 2001, she joined Animation World Magazine as general manager and was named managing editor in 2002.