Domande frequenti

Red's Dream was, in part, a rendering 'test' for the new Pixar Image Computer. Many people don't know that Pixar was primarily in the computer hardware business for several years after it was formed in 1986, and produced a versatile, albeit complicated graphics computer that competed successfully for digital compositing and 3D rendering until late eighties and early nineties. This hardware was the culmination of Lucasfilm Computer Division's efforts to build a universal digital compositing engine to overcome the challenges of optical compositing. The hardware turned out to be much more versatile than just the demands of compositing, and was repurposed for a variety of areas in graphics including terrain rendering, 3D rendering, volume rendering, etc.

The dream sequence, where Red juggles from Red's Dream was a proof of concept for the capabilities of this machine, incorporating many advanced computer rendering capabilities that had only existed in Pixar's software-based Renderman software until then.

The hardware business eventually was not able to compete successfully against Silicon Graphics. Pixar, under Steve Jobs's ownership, decided to focus exclusively on developing its animation properties.

Reyes was the general purpose rendering system for Lucasfilm Computer Division (which was to become Pixar in 1986). Nominally named for Pt. Reyes, a scenic spot not far from the Lucasfilm offices, there was some internal discussion that it actually meant "Renders Everything You Ever Saw" (which makes for a better story!). The Chap was the "Channel Processor" which was the integral CPU/graphics processing board for the Pixar Image Computer described above. A special painfully hand-coded subset of Reyes was brought to the Chap and hence becoming "ChapReyes".

Reyes morphed over the years becoming some of the foundational technologies, if not actual code, for Pixar's formidable Renderman rendering software.

Although in screentime the film is dominated by the Red's Dream Sequence, the scenes before and after in the bike shop were incredibly computationally expensive due to intricate shading requirements and produced on general purpose computers, not the ultra-fast (but highly specialized Pixar Image Computer).

Red's Dream was produced for the summer SIGGRAPH conference in 1987, which had a hard deadline. As the time approached the cost of rendering a particularly expensive sequence where the camera tilts up in front of the bike shop seemed like it was going to cut things a too close to the deadline. It appeared likely there were just not enough rendering cycles left to complete the film.

The graphics gurus, led by Robert L. Cook, realized that a camera tilt with no panning motion horizontally or vertically exposed no new hidden surface information. Therefore - this is the miracle part - the entire sequence could be composed from various intermediate images, with the intermediate (missing frames) computed exclusively via image transformation and composition, thus saving many weeks for rendering time (as only a few 'expensive' frames were needed, the rest being cheap-to-compute image transformations). This is a fairly well-known technique these days, but back then was rare and may well have been the first use of this neat trick.

Mark Learther.

Not the very first, but one of the first. Luxo Jr. was made the year before.