Drag Me to Hell, directed by Sam Raimi, tells the story of a woman who is haunted by a demon. Throughout most of the film the demon only appears in shadows and even in the climatic scene where the demon is finally revealed, it is only for a brief second. This did not, however, make the job of creating the full CG monster any easier as the film’s visual effects supervisor Bruce Jones mandated that the CG monster hold up visually even when it was viewed frame-by-frame. Culver City-based I.E. Effects was originally brought on to do some rough CG for blocking purposes while the film was still being shot but based on this work they were awarded the job of creating the full CG monster, as well as other effects for the film. We spoke with I.E. Effects’ visual effects supervisor Aaron Kaminer about their work on Drag Me to Hell.
How did your task evolve from creating the pre-vis to creating the CG monster?
In this case we were calling it ‘post-vis’ because they had already shot the footage and done the first version of the edit for this one scene in Christine’s bedroom. They wanted us to help with blocking the scene based on their notes and interjecting our artistic interpretation. It is the scene where Christine (played by Alison Lohman) gets knocked to the floor when a window explodes. She is then pulled up into the rafters of this loft and thrown around in the room. We took that footage and did fast and dirty comps, tracked the camera moves in 3D, built a rough version of the ceiling in CG and did all the blocking for the scene 3D in terms of how the debris would fly around in the scene as she is getting thrown around. From there they decided to award us the finals for that sequence and that is how we got our foot in the door for the project.

At that point we hadn’t done any previs for the monster. There were shots at the beginning of that sequence based on some other tests with the hands coming underneath the door. We were doing character animation on the hands and that expanded into doing the full CG modeling, texturing and animation for the monster.

Was the look of the monster defined when they awarded the CG shots to you?
There were reference sketches of the monster. It was very rough and it didn’t have all the final detail. It was just a face of the monster and didn’t go beyond that. The other asset they had for us we a 3D model, a very low-res 3D model they used to do pre-vis for the monster. But the actual shape and build of the monster came from how it needed to be used in the shots.

They had a lot of shots where they wanted the monster to be seen on the walls just as a shadow. They wanted to keep it be very mysterious so that the form of it was not readable, just for the sake of suspense and keeping the audience in the dark. We built the monster how it was going to be used for final shots, and then it was dialed back from there.

Talk about the monster shots that you handled.
Throughout the film they never wanted to show too much of the monster in order to keep the suspense and not to cheapen the effect. The shots of the monster were very brief but they were fairly important because they were the only shots where you see the monster in full detail. In the scene in Christine’s bedroom she has run into her room as these shadows are chasing her. She runs to the window to try to escape and then the monster, fully-formed, jumps up into the window giving a big scare to the audience. Those were the two shots in the sequence where we had to feature close-ups on the monster in full resolution. Another shot we’d done with the monster is when she goes to visit a psychic to help her with this demon that is haunting her. The psychic sees a vision of the monster surrounded by flames.

The fact that the monster only appears for a brief second didn’t make the CG work that much easier I assume.
Bruce Jones, the visual effects supervisor for the film, always had the mandate that the shots of the monster that would hold up when someone went through the Blu-ray DVD and stepped through the shot frame-by-frame. So the level of quality, however brief, had to be as high as possible.

What was difficult about this particular CG character?
We had created wings on the demon, almost like dragon wings coming off its sides, The wings were these tattered, disgusting flaps of skin. The rig for the tattered dragon wings was pretty difficult because we needed to make it behave dynamically and have a life of its own. One analogy is that the wings are getting blown around by some supernatural wind force that may not have been present in the scene but applied to it. Another way we looked at it was having a mess of writhing snakes that moved on their own. So that was difficult.

For the wings there were three levels of animation. The first level was being able to keyframe any joints traditionally. The second was to turn on a procedural noise that would run through them, which is a lot faster to calculate than doing dynamics like wind, so we had controls for how dense the noise was and how quickly it was moving. The third level of animation was on the loose pieces of skin from the wings we had proper dynamics built in. So it was a mix of techniques.

The other thing was, because the shots were close-ups of the face we had to build a solid facial rig that would deform the face similar to the way musculature deformed a face. We had full range of animation in the face and all the controls for animators to use. We didn’t want to look cheap.

What tools did you use to create the effects?
Model was done in Zbrush, all the rigging, animation, rendering done in Maya and the final composite was done in Digital Fusion.

And the model you created was used by other visual effects vendors working on the film as well?
Yes, once we got the model approved we did the rigging and started using it for our shots as well as providing the model to other visual effects vendors. The other vendors needed to use the model and the rig for the shots where the monster appears as shadows on the walls. We were the contact point for that model and rig for the other visual effects vendors.

We handed them the 3D files that contained the model and rig and also built up documentation describing all the tools built into the rig about how to control it and then stayed in contact with the other vendors if they needed troubleshooting.

In addition to the CG demon, I.E. Effects handled a bunch of other shots as well. Anything particularly challenging?
There was a lot of the normal cleanup and compositing shots. There was one scene where Christine runs up the stairs and she is wearing these big black boots. For continuity she is supposed to be barefoot. So for continuity we had to remove the boots and create full CG feet below her shins, replace all the lighting and shadows and animate and track them as she runs up the stairs. That was pretty difficult and time-consuming.