Issue: Volume: 22 Issue: 12 (December 1999)

SIMULATION: Forensic Animation

By Karen Moltenbrey

More than six years have passed since Juan Jesus Posadas Ocampo, a cardinal in the Catholic Church, was killed during a shoot-out by drug cartel members at the Guadalajara international airport in Jalisco, Mexico. Since then, rumors and theories about the incident and the priest's possible involvement with Mexican drug lords have persisted, mainly because the facts of the case-labeled a political assassination by the Mexican government-have never been released to the public. But now a 3D simulation of the event, sanctioned and used by government officials to aid in their investigation, will be broadcast on Mex i can national television.

"There has been a lot of speculation long after the cardinal's assassination over whether his death was a result of his involvement with drug dealers or if he was just in the wrong place at the wrong time," says animator Fernando Gonzalez, owner of Digital Shop, the small animation boutique in Mexico City that created the 70-second simulation.

Mexican officials hired animators to re-create their official case file on the 1993 assassination of Cardinal Posadas, the archbishop of Guadalajara. The police are hoping that the simulation, which will be aired on national television in Mexico, will finally lay to rest years of public and political dispute concerning the murder.

This debate has not been limited to the public arena. There has also been reported disagreement over the facts of the case among the Catholic Church, the Jalisco State Government, and the Pro cur a duria General de la Republica (PGR), the Mexican counterpart to the FBI in the US. Were the cardinal and several other bystanders killed accidentally in a fusillade of AK-47 rifle fire during an unsuccessful "hit" on reputed drug lord Joaquin (Chapo) Guzman by a rival leader as he arrived at the airport? Or was the cardinal the intended target because of an alleged relationship with one of the crime leaders or because he possessed information linking government officials to drug activity?

In an attempt to help the investigators better sort out the facts and possibly reach an official agreement, forensic criminologist Epifanio Salazar, head of the PGR's Caso Posadas special investigative unit, hired Digital Shop to re-create the shooting using computer graphics. After months of political and public pressure, the PGR has agreed to release the simulation, and its findings, to the national media in Mexico so the public can "view" the facts for themselves.

Creating what is believed to be Mexico's first forensic animation required the same type of accuracy the police officials used during their investigation of the initial crime scene. "Everything in the simulation had to be exactly as it was on that day," Gonzalez says. Every person and object had to be modeled to the exact size, scale, and location, and each bullet had to follow a specific path in order for the action to unfold as it actually occurred. If a vehicle were to be placed one meter too far to the left, for instance, it could have affected the entire scenario by blocking a victim.

To ensure that the 3D version depicted the actual events, the PGR provided Digital Shop with boxes of its top-secret investigative files-including thousands of photographs, numerous eyewitness testimonies, measurements, autopsy reports, and laser-beam studies of the bullet trajectories. Also included were detailed diagrams by law-enforcement officials showing the exact positions of the victims and the shooters, as well as the bullet paths.

Since the entire scenario unfolded at the airport, the first modeling task for the four-person Digital Shop team was to replicate the building and its surroundings. To achieve the exact scale of the airport, Gonzalez used the 2D architectural plans of the structure as a guideline for his 3D model, which he produced with NewTek's (San Antonio, TX) Lightwave on an Intergraph (Huntsville, AL) TDZ 600 workstation. "They even wanted us to include the bricks in the entranceway to the airport," he says, which were built with Enzyme Studios' (Auckland, New Zealand) procedural shaders.

The next CG hurdle was to hand-model the 1000 vehicles appearing in the crime-scene photographs. To speed the process, the artists made simplistic, boxy models for the vehicles in the far background, and built more complex versions-completely textured and shadowed-only for those close to the action.

Because the simulation was used as an investigative tool, the artists had to follow exact specifications for modeling and placing the images.

Because many of those believed to have been involved in the shoot-out were killed or later arrested (some on unrelated charges), the investigators were able to provide the animators with descriptions of the characters, which were modeled in Lightwave. While each character's height and weight were important to the re-creation, the simulation didn't require the artists to clone the individuals' actual faces. Instead, they painted and mapped generic facial textures using Adobe Systems' (San Jose, CA) Photoshop, and used Metacreations' (Car pin teria, CA) Painter 5, NewTek's Aura, and a variety of shaders for the other character and object textures.

The most challenging part of the project involved the character animation. "We animated about 20 characters performing specific actions in eight different scenes, and the dynamics of all that movement had to be right on," Gonzalez notes. "It would have been easier to do this in Maya or another package, but the necessary tools were not available here at the time," he says. Instead, animator Jose Kuri used Fori Owurowa's Puppet Master (Virtual Reality Pictures; New York), a Lightwave plug-in that "slices" models into a number of pieces that are animated through inverse kinematics to achieve independent movement. He then used Metamation, another Light wave plug-in, to convert the low-resolution models to high-resolution versions for the simulation.

Even the bullets were represented graphically, using single-line polygons with a clip sequence map painted in Aura to achieve a moving "dotted" line from the guns to the points of impact. To simulate the blood particles, the group used NewTek's HyperVoxels technology.

Using NewTek's Lightwave, the animators hand-modeled more than 1000 vehicles appearing in the crime-scene photographs, adding more details to those closer to the camera.

Using Lightwave's Screamernet, the group spent about 80 hours rendering the 2000 frames on a renderfarm of Intergraph work stations and Pen tium PCs running Windows NT. The final cut, which contains more than 260 3D objects with a polygonal count of about 263,000, was edited on a Speed Razor non-linear editing suite from in:sync (Bethesda, MD).

The digital re-creation proved to be a valuable investigative tool. Prior to contacting Digital Shop, the PGR had attempted to re-enact the crime scene using physical models that moved on wires, "but it looked horrible, and things didn't move accurately," Gonzalez says.

However, using computer graph ics en abled the PGR in ves tigators to get up close to the action for each shoot ing, then watch the entire scene unfold from a bird's-eye view, a unique per spective that could not be achieved any other way. "They were able to see everything occur right before their eyes, which was their main objective for making the simulation. They could even zoom in about three meters from the person who shot the cardinal," he adds. "The simulation did everything they wanted it to do."

Since the PGR had not publicly commented on the evidence as of press time, it is unknown whether the simulation unveiled any startling new information. And whether or not the animation will finally end the speculation and bring a definitive close to the case is still anyone's guess, as no plans were announced as of press time for the federal, state, and church officials to collectively review and discuss the visualization.

An earlier attempt to resolve the issue occurred a year ago, when an Inter-In sti tu tional Commission comprising Jal isco officials and the Guadalajara archdiocese re viewed the evidence. While that investigation spawned a series of related events, in cluding dozens of criminal charges, it failed to result in a consensus concerning a motive, with reports claiming that the government believes the cardinal was killed by mistake, while the cardinal's successor has been quoted as rejecting that theory. He maintains that Posadas was killed deliberately because he possessed sensitive information concerning government officials' involvement in the drug trade. As of press time, the simulation had not been publicly released, and the special investigative unit assigned to this case was still active.

Key Tool Lightwave, NewTek (