Today the concept of 3D card has disappeared since it was integrated into the graphics card, but at the beginning the two components were separated and therefore we needed two cards: one for 2D and one for 3D. Although they all inherited the basic operating mode of the Silicon Graphics Reality Engine with improvements and additions over time, the truth is that the first models that hit the market were low performing and called 3D decelerators.
The history of 3Dfx Voodoo Graphics
In 1994, Gary Tarolli, Scott Sellers and Ross Smith founded a company called 3Dfx Interactive. An emerging company that had a very short life, but that marked the world of PC video games during the second half of the 90s. A series of bad decisions and not knowing how to read the market led them to bankruptcy, however they have the honor of creating the first 3D card for video games, called Voodoo Graphics, also called SST-1 and thanks to its power and ease of programming Glide graphics API I ended up dominating the 3D PC gaming market, just as the Sound Blaster had done with sound.
The origins of Voodoo Graphics can be found in Silicon Graphics’ Iris Indigo. A cheap workstation I had worked on, Gary Tarolli. Its peculiarity is that it lacked the hardware to run the front-end of the 3D pipeline. That is to say, it left the work of calculating the geometry of the scene to the processor, but the work of pixelating, texturing and drawing on the screen was carried out by said card. Principle they applied with the first 3Dfx product.
At the same time, another of the founders, Scott Settlers, created a company called Pellucid which was not very successful and whose objective was to create a graphics system which would allow a PC to have the same level as an SGI workstation, the result it was a double card called Irisvision and unfortunately I go very unnoticed due to the lack of software and support. Frustrated, the settlers himself reunited Tarolli and Smith. to found 3Dfx Interactive in 1994.
The first steps in the arcades
At that time 3D graphics on PC were not very popular, at most we had DOOM and its clones which were based on the use of the Ray Casting technique with voxels or volumetric pixels, but nothing to use 3D graphics based on building models with vertices. This was because the floating point computing power of processors like the 486 was limited. Silicon Graphics workstations used processors from the now defunct MIPS brand. Which SONY and Nintendo would also adopt in their first consoles with support for three-dimensional graphics.
Because in his project he couldn’t copy the OpenGL or IrisGL on which the Iris Indigo hardware was based. So they made a copy of the modified API with some functionality removed to see how a 90 MHz Pentium could run the scene geometry, which would not work in future Voodoo Graphics. They obtained more than satisfactory results, with an average of 300K triangles per second. On par with arcade machines of the time and above PlayStation and Nintendo64.
The goal was to release the SST-1 or Voodoo Graphics first in the arcades. In them, he had started appearing in a competition between SEGA and Namco which was actually a secret competition between Martin Marrieta (later Lockhead Martin) and Evans & Sutherland. So 3Dfx via the possibility of entering this market, which was its initial objective.
Entry into the PC world
3Dfx’s luck changed thanks to a carom, for years the price of RAM memory skyrocketed due to the fact that in the middle of the MS-DOS era it was not usual to see configurations of large capacity memory. The paradox was that it was very cheap to manufacture, but since there was no demand from applications, manufacturers kept it at a premium. Which also affected the rest of the hardware.
The arrival of Windows 95 and the high RAM requirements of the time They brought down the price of EDO RAM, which was used by Voodoo Graphics, and made it cost effective to use for PCs.. However, it was necessary to adapt the games for the Glide API so that they could be used in all their glory. ANDthe first to do so was the first Tomb Raider and would be followed by an adapted version of Quake. Thanks to Voodoo Graphics, we went from pixelated graphics of 320 x 240 pixels to 640 x 480. That is, quadruple the resolution and with texture filtering and other effects.
Such was the impact and success that they started flying out of stores and the rest of the companies started creating patches and updates for their games. The PC became from that moment the technological king in terms of games, proving to be years ahead of the consoles in terms of graphics technology.
Voodoo graphic architecture
You can see the architecture of Voodoo Graphics in the diagram below, It is based on two different chips called FBI and TREX. there the EDO RAM memory is divided into two different wells. In the first, the frame buffer and depth buffer are drawn, and in the second, textures are found, which are images used to be placed on objects to represent the materials they are made of.
Implementation of a limited version of the 3d pipeline there requires an additional SVGA card to work, the two interfaced with each other via a VGA-to-VGA cable, and Voodoo graphics are bypassed except with Glide or MiniGL (a simplified version of OpenGL) applications, at which point it took over. Of course, it had a series of resolution limitations, since could only produce images in 640 x 480 or 800 x 600 pixels at full screen. As it lacked the necessary mechanisms to create a composite frame buffer.
How did it work?
In each frame of the game, Voodoo Graphics performed the following steps in an orderly and repetitive fashion:
- Rendering processes the geometry of the scene and creates a screen listing of everything Voodoo Graphics has to do with the various triangles that make it up. This list is sent via the PCI port, which should not be confused with the current PCI Express.
- The list of triangles is received on the fly by the FBI chip, which performs the rasterization process, which converts the 3D vector information into groups of pixels in 2D space so that TREX can treat it as such.
- Once the FBI has created the groups of pixels, it’s time to send them to TREX, which will use its texture memory to color each object correctly. This chip will also perform texture filtering, as well as other color mixing processes.
- In the last step, TREX sends the already textured pixel triangles back to the FBI, who will take care of ordering them to write them to the framebuffer for later sending to the monitor.
Finally, did you have this 3D card or one of its successors in your old PC? Leave it to us in the comments and share your memories.
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