Actually the elaborate landscapes were not the biggest challenge on the project.

Once in Madrid, Burrell says they worked out a fairly effective system from the get go to establish limits and a true appraisal of what their artists would need to create. "We worked out all the shots. We were on set almost every day, six days a week. Actually, seven days a week because on Sundays we'd spend with Guillermo in the editing room. So it was a labor and I mean labor of love," he laughs. "We'd all seen the script and he had very elaborate storyboards. We did some previs for a couple key transition scenes where there are multiple shots rolled into one. But most of it was so well storyboarded we didn't need a lot of previs, but we did a lot of animation casts in terms of the style of the creatures like the stick bug and the fairies. We went through all the dynamics of getting that look nailed down while we were shooting. The cool thing about Guillermo is that we agreed on our shot list and it was about 200 that we were budgeted at. Then we started shooting and he was editing at the same time, which is really cool, so in our first turnover session we immediately saw that we were over-budget. If you shoot a plate of an actor talking and that runs a minute long and it cuts back to it five times -- the rule of thumb in Hollywood usually is if its more than two feet of film between cuts, it becomes a separate shot. We held to that rule and so did Guillermo but the problem became that one plate now turned out to be six shots because of the cutting. We all said, 'Oh shit!' But we worked it out and he worked with us on that. He wasn't happy but he understood we couldn't balloon to over 400 shots. We're not there to stamp on his creativity, but we were there to warn him."

While the intricate landscapes of the labyrinth world would seem the most daunting aspect of the project, Burrell says the real challenges actually came more from del Toro's shooting style than achieving his artistic vision. "Every shot that involved any kind of 3D asset had to be camera tracked," Burrell sighs. "We had an enormous amount of camera tracking. Without a good foundation of a good camera track, your timing is screwed and that wasn't foreseen. I kind of had an idea that he wanted to move the camera but he moved it all the time with Steadicam or Technocrane. And then we were blocking out all the character animation and that was a whole performance thing and Guillermo was very involved in that. We had a stick bug, three fairies and a mandrake root. We also had a CG toad. The fairies were pretty complicated with what they had to do, so we did a lot of research. We met an entomologist here in Arroyo Grande who had a huge collection of real bugs and he had a bunch of stick bugs and he gave us two that we named Cheech and Chong. They were great reference. They were incredibly gentle creatures and it was really neat to have that to motivate the artists. But we showed [the bugs] to Guillermo and he was like. 'No, no! They need to fly and jump around!'" Burrell laughs. "We then had a dancer come in for some fairy reference and that really, really helped for all the mannerisms of a human being. We didn't do any motion capture but we shot a lot of reference for the stick bug and the fairies."

Burrell singles out the appearance of the stick bug as one of the many vfx highlights of the film.

While the filmmakers labored in Spain, they developed a system to get the Cafe team up and running to make the post-production timeline. "Thank god for the Internet!" Burrell enthuses. "Every day we would get dailies uploaded to the FTP site [for the artists] to look at. Also every week, I would also burn a DVD of all the reference I took on set and then we would videotape the turnover with Guillermo every Sunday. I would videotape him watching the Avid and describing what he wanted in a shot. I would burn a DVD of that and a QuickTime of exactly what we were watching on the Avid, so they got all this reference, all this great HDRI stuff and this great stuff from Guillermo saying exactly what he wanted, so there was no misunderstanding. We called the sessions 'GDT Speaks' and put them on the artists' desktop and I said, 'If there is any doubt in your mind of what to do, watch the QuickTime.' It was like having the director over your shoulder."

Pan's ended up recruiting a lot of the top talent at Cafe to collaborate on the shot creation, Burrell admits. "We had between five and ten artists in the early stages and then it got to about 20 right when we got back from Spain and then it ballooned to about 40 at the end. The bulk of the artists were compositors but it was also a heavy CG team with lighting and tding. We mostly used Maya and mental ray. We used XSI for modeling and then some little specific things to help create a certain morphing technique called Shrink Wrap, to make the stick bug change into the fairy. It was pretty elaborate. We used Digital Fusion for compositing and LightWave for the end throne room scene because it was all hard surface stuff and LightWave is great at that."

With the visual wonders abound in the film, Burrell says it's hard picking one favorite sequence they created, but he offers, "There are a couple shots with the stick bug that I am really proud of -- one in the beginning where it crawls around a tree that is phenomenal. It really integrated well and I was really happy with that. Some of the throne room stuff at the end is nice. I am pretty happy with all of it. If I could single one thing out, it would probably be where Ophelia is running into the labyrinth and the walls magically open up for her. She runs to safety into the middle of the labyrinth and they close back up again and that shot was just brilliant and it was done by one of our CG sups here, Akira Orikasa. He just did a great job. It was really magical and had the quality that Guillermo wanted. He nailed it. I was very lucky... And Guillermo is a great motivator and a great communicator. People love doing good for him because he is so proud and makes you proud of the work."

Tara DiLullo is an East coast-based writer whose articles have appeared in publications such as SCI FI Magazine, SFX and Lost Magazine. She is the author of the books 300: The Art of the Film and 24: The Official Companion Guide: Seasons 1 & 2.