Pixar Image Computer
 Pixar Animation Studios' own P-II Pixar Image Computer. | |
| Developer | Pixar |
|---|---|
| Manufacturer | Pixar |
| Type | Image processing |
| Release date | July 24, 1986 |
| Units sold | Fewer than 300 |
The Pixar Image Computer is a graphics computer originally developed by the Graphics Group, the computer division of Lucasfilm, which was later renamed Pixar. Aimed at commercial and scientific high-end visualization markets, such as medicine, geophysics and meteorology, the original machine was advanced for its time, but sold poorly.
History
[edit]Creation
[edit]When George Lucas recruited people from NYIT in 1979 to start their Computer Division, the group was set to develop digital optical printing, digital audio, digital non-linear editing and computer graphics.[1] Computer graphics quality was just not good enough due to technological limitations at the time. The team then decided to solve the problem by starting a hardware project, building what they would call the Pixar Image Computer, a machine with more computational power that was able to produce images with higher resolution.[2]
Availability
[edit]About three months after their acquisition by Steve Jobs on February 3, 1986, the computer became commercially available for the first time, and was aimed at commercial and scientific high-end visualization markets, such as medical imaging, geophysics, and meteorology.[3][4] The machine sold for $135,000, but also required a $35,000 workstation from Sun Microsystems or Silicon Graphics (in total, equivalent to $490,000 in 2024). The original machine was well ahead of its time and generated many single sales, for labs and research.[5] However, the system did not sell in quantity.
In 1987, Pixar redesigned the machine to create the P-II second generation machine, which sold for $30,000.[6] In an attempt to gain a foothold in the medical market, Pixar donated ten machines to leading hospitals and sent marketing people to doctors' conventions. However, this had little effect on sales, despite the machine's ability to render CAT scan data in 3D. Pixar did get a contract with the manufacturer of CAT Scanners, which sold 30 machines. By 1988 Pixar had only sold 120 Pixar Image Computers.[5]
In 1988, Pixar began the development of the PII-9, a nine-slot version of the low cost P-II. This machine was coupled with a very early RAID model,[7] a high performance bus, a hardware image decompression card, 4 processors (called Chaps or channel processors), very large memory cards (VME sized card full of memory), high resolutions video cards with 10-bit DACs which were programmable for a variety of frame rates and resolutions, and finally an overlay board which ran NeWS, as well as the 9-slot chassis. A full-up system was quite expensive, as the 3 GiB RAID was $300,000 alone. At this time in history most file systems could only address 2 GiB of disk. This system was aimed at high-end government imaging applications, which were done by dedicated systems produced by the aerospace industry and which cost a million dollars a seat. The PII-9 and the associated software became the prototype of the next generation of commercial "low cost" workstations.
Demise and legacy
[edit]In 1990, the Pixar Image Computer was defining the state-of-the-art in commercial image processing. Despite this, the government decided that the per-seat cost was still too high for mass deployment and to wait for the next generation systems to achieve cost reductions. This decision was the catalyst for Pixar to lay off its hardware engineers and sell the imaging business. There were no high volume buyers in any industry. Fewer than 300 Pixar Image Computers were ever sold.[8]
"It was built to be part of a pipeline, but as we developed it we realized we were competing with Moore's law with CPU and we probably couldn't get far enough ahead of it to justify it so we actually stopped the hardware effort."
— Ed Catmull, President of Pixar[9]
The Pixar computer business was sold to Vicom Systems in 1990 for $2,000,000. Vicom Systems filed for Chapter 11 within a year afterwards.
Many of the lessons learned from the Pixar Image Computer made it into the Low Cost Workstation (LCWS) and Commercial Analyst Workstation (CAWS) program guidelines in the early and mid 1990s. The government mass deployment that drove the PII-9 development occurred in the late 1990s, in a program called Integrated Exploitation Capability (IEC).
Design
[edit]The P-II could have two Channel Processors, or Chaps. The chassis could hold 4 cards. The PII-9 could hold 9 cards (4 Chaps, 2 video processors, 2 Off Screen Memory (OSM) cards, and an Overlay Board for the NeWS windowing system). NeWS was extended to control the image pipeline for roaming, image comparison, and stereo image viewing.
Each Chap is a 4-way parallel (RGBA) image computer.[10] This was a SIMD architecture, which was good for imagery and video applications. It processed four image channels in parallel, one for red, one for green, one for blue, and one for the alpha channel (whose inventors have connections to Pixar).[2][11] Images were stored with 12 bits per color channel (or 48 bits per pixel).[8] The 12-bit data represented an unusual (for today) fixed-point format that ranged from -1.5 to 2.5 using 2 bits for the integer portion, meaning the range from 0 to 1 had 10 bit accuracy.
A Unix host machine was generally needed to operate it (to provide a keyboard and mouse for user input). The system could communicate image data externally over an 80M per second "Yapbus" or a 2M per second multibus to other hosts, data sources, or disks, and had a performance measured equivalent to 200 VUPS, or 200 times the speed of a VAX-11/780.[12][clarification needed]
PXR File Format
[edit]Pixar Image Computer use 'Pixar storage standard' PXR File format. PXR file have structure[13]:
1. Header (512 bytes)
2. Tile pointer table (8 × numberTiles bytes)
3. Picture data
Origin of image is left top corner. All data in file use small endian byte order.
Header (512 bytes)
[edit]| Field number | Offset (hex) | Length | Field name | Description |
|---|---|---|---|---|
| 1 | 0 (0x0000) | 4 bytes | file signature/magic number | 0x80 0xe8 0x00 0x00 (value is 0x0000e880)
|
| 2 | 4 (0x0004) | 2 bytes | Version | File format version (only have version 0) |
| 3 | 6 (0x0006) | 246 bytes | Ascii description | String for file description |
| 4 | 252 (0x00fc) | 4 | Label Pointer | For continue label if need label longer than 246 bytes. Pointer address from start of file. |
| 6 | 256 (0x0100) | 160 bytes | Unused | Unused |
| 7 | 416 (0x01a0) | 2 bytes | Picture height | Pixar height of whole picture |
| 8 | 418 (0x01a2) | 2 bytes | Picture width | Pixel width of full picture |
| 9 | 420 (0x01a4) | 2 bytes | Tile height | Pixel height of each tile (≤ full picture height) |
| 10 | 422 (0x01a6) | 2 bytes | Tile width | Pixel width of each tile (≤ full picture width) |
| 11 | 424 (0x01a8) | 2 bytes | Picture format | 4 bits for tell which channel is in file: R = bit 0, G = bit 1, B = bit 2, A = bit 3; 4 low bits in low byte.
|
| 12 | 426 (0x01aa) | 2 bytes | Picture storage | Picture encoding and number bits. Have 4 values: 0 = 8 bit encoded, 1 = 12 bit encoded, 2 = 8 bit dumped, 3 = 12 bit dumped
|
| 13 | 428 (0x01ac) | 2 bytes | Blocking factor | Optimum disk transfer chunk |
| 14 | 430 (0x01ae) | 2 bytes | Alpha mode | Have 2 value: 0 = matted-to-black (pre multiply); 1 = unassociated
|
| 15 | 432 (0x01b0) | 2 bytes | x offset | x offset for picture |
| 16 | 434 (0x01b2) | 2 bytes | y offset | y offset for picture |
| 17 | 436 (0x01b4) | 76 bytes | Unused | Unused |
Tile Pointer Table (8 × numberTiles bytes)
[edit]Tile pointer table start at byte 512 from start of file and have 1+ tile pointers.
| 512 (0x200) | Tile pointer 1 | Address of tile 0 (4 bytes) | Length of tile 0 data (4 bytes) |
|---|---|---|---|
| 520 (0x208) | Tile pointer 2 | Address of tile 1 (4 bytes) | Length of tile 1 data (4 bytes) |
| ... | ... | ... | ... |
For calculate number of tiles for x direction:
1 + (pictureWidth - 1)/tileWidth
and y direction:
1 + (pictureHeigth - 1)/tileHeight
Tile order is sweep from left to right, from top to bottom; first tile 0 is at left top of picture and last tile (totalNumberTiles - 1) is at right bottom of image.
Use
[edit] | This section needs additional citations for verification. (December 2020) |
In the early 1990s, the Pixar Computer was used for medical imaging, including MRI and CT scans at Georgetown University[8] and mammography at University of California.[14]
Walt Disney Feature Animation, whose parent company later purchased Pixar in 2006,[15] used dozens of the Pixar Image Computers for their Computer Animation Production System (CAPS) and was using them in production up through Pocahontas in 1995.[citation needed]
References
[edit]- ^ "John Lasseter on Pixar's early days -- and how 'Toy Story' couldn't have happened without Tim Burton". Entertainment Weekly's EW.com. Retrieved 22 April 2015.
- ^ a b John Celestri (3 September 2011). "John The Animator Guy". johncelestri.blogspot.com. Retrieved 22 April 2015. [self-published source?]
- ^ Winter, Christine (10 February 1986). "Pixar May Be The New Apple Of Jobs' Eye". Chicago Tribune. Retrieved 22 April 2015.
- ^ CNet News Staff (5 October 2011). "Steve Jobs: A timeline". CNet.
- ^ a b Deutschman, Alan (2000). The second coming of Steve Jobs. New York: Broadway Books. pp. 118–21. ISBN 0-7679-0432-X.
- ^ Isaacson, Walter (2011). Steve Jobs. Simon & Schuster.
- ^ "Pixar Image Computer".
- ^ a b c "Pixar Image Computer". Rhode Island Computer Museum. Archived from the original on 9 March 2020.
- ^ "Pixar's RenderMan turns 25". 25 July 2013. Retrieved 2019-04-21.
- ^ Levinthal, Adam; Hanrahan, Pat; Paquette, Mike; Lawson, Jim (October 1987). "Parallel computers for graphics applications". In Randy Katz (ed.). Proceedings of the second international conference on Architectural support for programming languages and operating systems. Vol. 15. Palo Alto, CA: ACM SIGARCH/SIGPLAN/SIGOPS. pp. 193–8. doi:10.1145/36206.36202. ISBN 0818608056. S2CID 18834615.
- ^ Porter, Thomas; Tom Duff (1984). "Compositing digital images". Proceedings of the 11th annual conference on Computer graphics and interactive techniques. Computer Graphics. Vol. 18, no. 3. pp. 253–259. doi:10.1145/800031.808606. ISBN 0-89791-138-5. S2CID 18663039.
(Available at pixar.com.) - ^ Barbara Robertson (June 1986). "Pixar Goes Commercial in a new Market" (PDF). Computer Graphics World. pp. 61–70. Archived from the original (PDF) on 2012-01-13. Retrieved 2011-10-29.
- ^ Pixar Image Computer Users Manual v1.2 Dec 1986
- ^ Cao, Fei; Sickles, Edward A.; Huang, H. K.; Zhou, Xiaoqiang (June 1998). "Migration of the digital interactive breast-imaging teaching file". In Yongmin Kim; Seong Ki Mun (eds.). Medical Imaging 1998: Image Display. Medical Imaging '98. 21–26 February 1998. San Diego, CA. SPIE Proceedings. Vol. 3335. pp. 637–646. Bibcode:1998SPIE.3335..637C. doi:10.1117/12.312543.
- ^ La Monica, Paul R. (25 Jan 2006). "Disney buys Pixar". CNN Money. Retrieved 2017-04-25.
