 |
The Orphanage's Jonathan Rothbart on 'Goblet of Fire'
Date: Dec 17, 2005
Topic:
|
Visual effects supervisor Jonathan Rothbart of The Orphanage talks to vfxblog about his studio's work for Harry Potter and the Goblet of Fire.
Interview by Ian Failes
Can you give me an overview of The Orphanage's contribution to 'Goblet of Fire'?
 The Orphanage was primarily focused on the Pensieve sequence. This entailed creating the Pensieve bowl of floating liquid, the memory threads that Dumbledore pulls from his head and the Trial Chamber digital environment that Harry falls into. During this sequence, Harry discovers the Pensieve, which contains Dumbledore's memories. He eventually looks too closely into the bowl of memories and gets sucked into a memory of a younger Dumbledore. There are also other scenes in the film where we see Dumbledore actually extract memories from his head and place them into his Pensieve.
One of the biggest challenges of this sequence was not technical, but artistic. Often in films, the highly conceptual work is particularly difficult. Everyone has a different image in their head of what something should be and it is not always easy to articulate or transfer that verbal description into images. An artistic representation of what memory threads look like floating in a bowl of viscous liquid is a pretty broad thing. We spent the majority of our time designing the look of the threads and liquid and refining that look for the different angles that they appear in the sequence. Like many visual effects, things that look good from one angle don't necessarily work for others. Often you have to take very different approaches for the varying angles to make the effect work. I will say that this is some of most rewarding type of visual effects work. I really enjoy coming up with artist ideas and having the opportunity to design the look of shots. Many times we are given designs and looks that are predetermined and we are just implementers of an effect. While this has its own challenges, it is usually more technical than artistic.
Who were the key artists from The O who worked on the film?
We had a number of varying effects to create for the sequence. We needed to develop a look for both the memory liquid and the memory threads. Additionally, we had to design the Trial Chamber and Harry’s plunging through. The development of the memory liquid in the bowl was done by several artists. My Senior team included Associate VFX Supervisor Kevin Baillie and CG Supervisor Shadi Almassizadeh who both did an amazing job of keeping everything on track and catching all my misses. The bulk of the matte painting for the Trial Chamber was done by Emmanuel Shiu and Kristi Valk. For the Pensieve and memory threads, we had a number of excellent TDs that worked to complete different pieces of the effect, with Nathan Farris handling the brunt of it. Tim Teramoto and Jeff Willette were responsible for creating the memory threads that were done in Houdini. The lead compositor, Alex Prichard, did an amazing job in assuring consistency between compositing methodologies across the show, as well as ensuring that every pixel was perfect before a frame went out the door!
Did you look to any reference or pre-viz for the Pensieve shots?
One of the major inspirations for the memory threads floating in the bowl was jellyfish. Under certain lighting, they have that amazing look of being very thin and transparent with a magic glow about them. Additionally, their motion is so fluid and delicate; much like the personality we wanted to create for the memory treads.
Was there a specific approach you took to your shots in terms of a mix of CG and compositing?
On Harry Potter and the Goblet of Fire, we took a very compositing heavy approach to the effects. We were fully aware that both the Pensieve itself and Dumbledore's memory threads were very intangible effects; ones that would require many iterations, fast turnaround, and very granular control to achieve the desired look. We ended up using this approach not only for the development cycle of the effects, but also for all of the final shots. The glowy, ethereal nature of the Pensieve was especially well suited for a comp-centric workflow. The base elements and mattes were rendered in Houdini and 3ds Max using Brazil r/s. After which all of the glows, reflection distortions, 2.5D light rays, rising and falling of the thread groups in the bowl, light wraps, etc. were added by the compositor. We were all very pleased with the end results of this methodology from both a scheduling and aesthetic standpoint!
How did you achieve the look of the liquidy memory threads swirling underneath the Pensieve bowl?
We started by creating a number of still art pieces that we used as proposals for the direction of the shots in the future. After some back and forth, we were able to come up with a look that both Jimmy Mitchell and Mike Newell liked. We were then put to the task of creating that look in motion.
The first thing we created was a liquid that looked photo-real, but had to have personality and motion that could be controlled. We also needed to find an appropriate balance between what looks totally photo-real and what is artistically appealing. That balance is a never-ending challenge in visual effects. We had to be careful, because if you tip in either direction too much you can lose the goal of the shots. It is always important to show some restraint when you know you have control of everything. After establishing a working liquid, we created tools that enabled us to control the motion of the liquid that could then drive geometry so that we could apply our floating thread look as well. What we discovered was that once we put the look of the still art into motion, it didn't play out the way we had anticipated from the concept art, thus leading us down another path for that actual moving effect. The biggest challenge to the threads was creating something that showed the motion of the liquid and was able to give a sense of depth in the bowl, without being too murky. In the end, we achieved the look with a combination of packages each contributing to a different piece of the thread.
How were the shots of Dumbledore extracting his memory threads from his temple accomplished?
The memory threads were comprised of quite a few elements to achieve the desired look! The "thread groups" in the Pensieve bowl itself were approved before the threads coming out of Dumbledore's temple, so we had a rough look to match. The challenge was getting the threads to look as liquid-like and silvery coming off of the wand as they looked inside of the Pensieve's liquid! The idea was that the threads were like a bunch of silk wound together to create a larger thread. Applying this concept gave us many micro flickers that, when combined, danced along the core of the thread group. To bring the main thread groups to life, we ran dynamic simulations of a central "guide thread" in Maya which was then surrounded by 15-20 tubes of varying degrees of thickness, frizz and motion. That animation was tweaked by hand, then passed off to Mental Ray for Maya and Brazil r/s for 3ds Max to render the various necessary passes. Brazil was responsible for rendering a gelatinous liquid-like casing for the entire thread group, while Mental Ray rendered the silvery threads themselves and a highlight pass (generated from a moving HDR reflection source). These passes, along with ones specifically tailored to flare/blend the threads into his temple, were combined in Adobe's After Effects to create the final look.
What were the challenges of creating the CG Trial Chamber environment that Harry falls into?
The biggest challenge for the Trial Chamber was our shot where Harry falls through the bowl and into the chamber itself. This plunge posed a number of design complications as we had to tell the story of Harry transforming from a reflection on the surface of the bowl into a falling Harry in the Trial Chamber. We batted around a number of ideas on how to move between the two worlds. I do think the end result was very successful. For the Trial Chamber itself, it was fairly straight forward as a digital environment shot. The most complicated part was that we were moving through it, so it couldn’t just be a standard projection matte painting. It took a much broader combination of CG and matte painting to finish the shot. Additionally, we had to deal with the fact that all the lighting in the scene had a flicker to it – from the cool lighting of the caustic light above or the warm flicker from the fire bellow. Both forced us to have a much larger 3D component to the lighting than your standard matte painting shot.
Did you have to collaborate with any of the other effects houses on the show? How was your work reviewed by the overall vfx supe?
Our sequence was pretty independent from the other sequences in the film, so we didn't have any elements that had to be shared with other facilities. We had regular calls with Jimmy Mitchell from London. We used cineSync by Rising Sun Pictures to make it possible to discuss the footage and see what the other was looking at. It was a great process and it is the best way to review work remotely. Also, we had a fantastic color pipeline on the show. We were able to receive color LUTs from the DP straight out of the DI session and load them into our shot LUTs. It was very smooth and easy to make sure we were seeing what the production was seeing. I would love to do all my films that way.
Related Links
The Orphanage
Goblet of Fire Official Site
Special thanks to Jonathan Rothbart for talking to vfxblog, and to Rama Dunayevich for making it possible. Images copyright 2005 Warner Bros. All rights reserved.
| |
