placed on top of the background plate, and Vargas' shots were optically dissolved into an airbrushed disintegration effect which matched Vargas' position in every frame. The Ceti eel shots used several models, overseen by visual effects supervisor Ken Ralston, who had just finished creature design for Return of the Jedi. He tied a string to the eels to inch the models across the actors' faces before they entered the ear canal. The scene of a more mature eel leaving Chekov's ear was simulated by threading a microfilament through the floor of the set up to Koenig's ear. The scene was filmed with three variations, which Ralston described as "a dry shot, one with some blood, and the Fangoria shot, with a lot of gore." Footage of a giant model of Koenig's ear was discarded from the theatrical release due to the visceral reaction it elicited in test audiences. Additional optical effects were provided by Visual Concept Engineering (VCE), a small effects company headed by Peter Kuran; Kuran had previously worked at ILM and left after finishing The Empire Strikes Back. VCE provided effects including phaser beams, the Enterprise reactor, additional sand on Ceti Alpha V, and an updated transporter effect. Meyer and the production staff were adamant about not using freeze frames for the transporter, as had been done in the original television series. Scenes were shot so that conversations would continue while characters were in mid-transport, although much of the matte work VCE created was discarded when the production decided not to have as much action during transports. Computer graphics company Evans & Sutherland used the computer graphics-based Digistar planetarium system to generate the fields of stars, based on a database of real stars. The models of the ships were composited atop the star fields. The Evans & Sutherland team also produced the vector graphics tactical displays seen on the Enterprise and the simulator bridge.The Wrath of Khan was one of the first films to extensively use computer graphics to improve the visual quality and production speed of special effects shots. Among the film's technical achievements was cinema's first entirely computer-generated sequence, ILM's animation for the demonstration of the effects of the Genesis Device on a barren planet. The first concept for the shot took the form of a laboratory demonstration, where a rock would be placed in a chamber and turned into a flower. Veilleux suggested the sequence's