DL: Yes, with Robert, we're used to doing a lot of greenscreen backgrounds for Sin City and the other Spy Kids. On this project, it was all shot live so we had to integrate all of the features in the background plate. So, for instance, in the section with the cobras, we had integrate the cobras and do the integration with the leaves on the floor, so we had to replace the floor with CG so that you could have interaction when the cobras are moving and going toward the kid and trying to bite him. There was also R&D with the transformation of the kids into creatures; for example, the boy and girl transforming into wasps.

JK: Mainly, because Robert was trying to find something looking a little bit funny.

DL: And because in the 3-D world it wasn't just a transformation where you pop the new model in; it had to have the face come in first; then you have the wings and then the legs. It was more of a transition transformation than anything else. Also, we had Mr. Black Box, the creature at the end.

JK: This had lots of R&D because all of the little cubes are animated and each piece is moving all over the place.

A little "Crocodile Rock" required animating crocs that could walk like humans.

BD: And how did you animate that?

DL: It was procedural animation. We did a small program in XSI, which with sliders we could animate the intensity of the movement and the generation of the cubes. You could have one cube split into many cubes and, if you pushed the cube, it could also split into many small cubes, so we needed to animated a skeleton and put all of this cube generation onto that skeleton. So we had lots of tests that we shipped to Robert just to see if the level of complexity in the cubes was enough. Because if you have too many cubes, you lose the overall shape of the creature, so we had big cubes, small cubes. And it was all done in XSI with its scripting tool.

JK: And we used Flame and Fusion for compositing.

BD: And what other software did you use?

DL: 3D Equalizer, ZBrush. As you can imagine, there's tons of 3D tracking and extrapolation to integrate our creatures because there's straight live-action shooting.

Compared to the Black Box robot and crocs, the tiny alien and spaceship were more straightforward.

JK: For the space ship, it was straight forward. Troublemaker did the design and shipped it to us because they did some previs for a teaser. We received this very early and the spaceship was one of the only designs that we had to follow. We had to work on the textures and everything but we got very good direction of what Robert wanted.

DL: With all the challenges of doing creature animation, it was still a pretty straightforward movie for us. It wasn't the kind of movie where you stay for a long period of time on certain shots because they don't have a defined look. But also we've been working with Robert for a long time, so we really know what he looks for and I think he's really confident in us.

And even though our last movie with him was Sin City, it was like a continuation of the first Spy Kids movie, which had a lot of creature work. The other ones had more environment work. So it was the same kind of production as Spy Kids but nearly 10 years later.

JK: For me, it was really the same kind of shots -- creatures in live action environments.

BD: And the aliens?