7. Display calibration explains EDO DRAM (Extended Data Out DRAM): Extended Data Output DRAM. Some improvements to the DRAM access mode, shorten the time of memory efficient access. Vram (Video DRAM): Video RAM. This is specifically for dual port memory optimized for graphics (data exchange with RAMDAC and CPU), which can effectively prevent conflicts that occur when accessing other types of memory. WRAM (Windows Ram): Enhanced VRRAM, performance than VRAM increases by 20%, accelerating video functions such as transmission and mode padding. SDRAM (Synchronous DRAM): Synchronous DRAM. It works synchronously with the system bus to avoid additional waiting time required for the system bus to synchronize the asynchronous DRAM to speed up the transmission speed of the data. SGRAM (Synchronous Graphics DRAM): Synchronous Graphics RAM, enhanced SDROM. It supports writing masks and blocks. Write mask can reduce or eliminate read - modifications - write operations; block written to the foreground or background fill. SGRAM greatly accelerates data exchange between the memory and the bus. (, Such as: Ritai S680, Banshee) MDRAM (Multibank DRAM): Multi-segment DRAM. MDRAM can be divided into multiple independent valid segments, reducing each process at the time loss of display refresh, video output, or graphic acceleration. RDRAM (Rambus DRAM): Mainly used for special high-speed burst operations, with accessed frequency up to 500 MHz, and traditional memory can only be accessed at 50 MHz or 75MHz. RDRAM's 16 Bit bandwidth can reach 1.6 Gbps (EDO's limit bandwidth is 533Mbps), and 32bit bandwidth is up to 4 Gbps. Second, 3D graphics card basic 3D function: 1. Alpha Blending: Alpha mix. Alpha is a special passage in the color characteristics of the 3D texture element, using it to color mixing with the texture image, producing a transparent effect. 2. Billinear Filternig: Double line filtering. A texture mapping technique can reduce block diagrams due to unevenness of color distribution during texture. 3. DITHERING: Jitter. This is the alignment of the change color pixel (Pixel) to get a new color process. 4. Flad Shading: A basic drawing technology that uses the same color inside each triangle drawn. 5. Fogging: Atomization. Mix some color with background to hide background to achieve haze effect. 6. Gouraud Shading: Use the color of the triangle vertex to get the interposition of the triangle to each point in the triangle. 7. MIPMAP: MIP mapping. It can save different resolutions and sizes of texture graphics in memory, which allows texture smooth and change when 3D objects are moved. 8. Perspective Correction: Perspective correction. Different angles and distances can be more realistic in 3D scenes in 3D scenes. 9. Point Sampled: Point sampling. A simple texture mapping technology, with the nearest texture element to determine the color of the current point. 10. TEXTURE MAPPING: Texture Mapping. A bitmap or image is attached to the 3D object, making the object. 11. Transparency: Transparent. 12. Z-Buffer: It is a memory area for storing the field of field pixels.
13. Gamma Correction: Gamma correction. In order to compensate for graphical distortion due to display deviation, the gamma correction is corrective correctively. Third, 3D graphics card three API API (Application PROGAM Interface Application): It is a software interface for 3D applications and 3D graphics cards. 1.Direct 3D: It is the middle interface interface in Microsoft's Direct X. When some 3D functions cannot be implemented by hardware, Direct 3D can use software simulation most 3D functions, improve 3D graphic display speed, and its animation feature is quite high, which is very suitable for game development. 2.Heidi (also called Quick Draw 3D): It is a purely scheduled window, mainly suitable for application development, HEIDI flexible, can handle very complex geometric graphics, strong extension, support interactive rendering, most important It has been supported by Autodesk (Autodesk is a famous AutoCAD and 3D SUTDIO, 3DMAX Manufacturer) 3.opengl (Open 3D graphics library) is developed by SGI (SGI production non-PC graphics workstation) Companies, including its software Waterfull Alias Maya, its popularity is equivalent to Intel of the PC. OpenGL is a stand-alone platform with portability. It can quickly draw 2D and 3D objects, working together in distributed environments, is a standard application interface for large science and engineering for high complex 3D graphic design. 16-, 24- and 32-bit color: 16-bit color can display 65,536 different colors in the display, 24-bit color can display 16.7 million colors, and the 32-bit color is different, it is just technology One concept, it is true that the number of colors is just the same as 24-bit color, only 16.7 million colors. For the processor, processing 32-bit color graphic images is higher than the processing 24-bit color load, more workload, and the user needs to be more within 32-bit color mode. 2D card: There is no 3D acceleration engine ordinary display card. 3D card: show card with 3D graphic chip. Its hardware feature can complete the processing of three-dimensional images, to reduce the work burden for the CPU. Usually a 3D accelerator card also includes a 2D acceleration function, but there is a separate display card only having 3D image acceleration capabilities, such as VOODOO2. Accelerated Graphics Port (AGP) High-speed Graphics Acceleration Interface: AGP is a PC bus system, and its appearance is to make up for some shortcomings of PCI. AGP has a higher operating frequency than PCI, which means it has a higher transmission speed. AGP can use the system's memory as a material cache, and in the 3D graphics card of the PCI, the material can only be stored in the display card. Alpha Blending: It is used to make the object to generate transparent sense, such as blurred transparent sights that are blurred through water, glass, and the like. Previous software transparent processing is to give all transparent objects to give the same transparent parameters, which is obviously very unreal; today's hardware transparent mixing treatment adds a value to the pixel in red green blue, which has added a value to specifically store the transparency of the object. Advanced 3D chips should support at least 256 transparency, all objects (whether water or metal) are all values of transparency, only high and low.
Anisotropic Filtering: (Please refer to the second-line filtration and tri-linear filtration) Anisotropic filtration is the latest filtering method, it needs to sample 8 or more pixels around the map point, obtain The average is mapped to the pixel point. For many 3D acceleration cards, it is almost impossible to filter an anisotropy filtration using more than 8 pixels because it requires more pixel filling rates than tri-linear filtration. But for 3D games, anisotropic filtering is a very important feature because it can make the screen more realistic, naturally processed more slower than tri-lineary filtration. Anti-aliasing (edge softening or anti-aliasing): Since the object edge of the object in the 3D image exhibits a triangular sawtooth, the anti-aliasing is smooth and natural, improve the image quality to make it soft. method. The latest full-screen anti-aliasing can effectively eliminate the displacement phenomenon of polygon binding (especially smaller polygons), and reduce the distortion of the image. When the panoramic anti-aliasing is treated, the pixels near the image shall be sampled 2-4 times to achieve different levels of anti-aliasing effects. 3DFX adds the choice of 2x2 or 4x4 anti-aliasing effect in the drive. According to the series chip, the two-chip VOODOO5 will provide 2x2 anti-aliasing effect, and the card of the four-chip can provide a higher 4x4 anti-aliasing level. In short, it is to mix the image edge and the pixel colors on both sides, and then replace the point in the original position with the newly generated point to achieve the shape of the softened object, eliminate the effect of the zigzag. API (Application Programming Interface) application interface: API is an interface exists between 3D programs and 3D display cards, which makes the software over hardware. To use a 3D acceleration function, you must use the API supported by the display card to write programs, such as Glide, Direct3D, or OpenGL. Bi-linear filtering: It is the most basic 3D technology, now almost all 3D acceleration cards and games support this filtering effect. When a texture is made small, it will inevitably appear "mosaic" phenomenon, and filter can effectively solve this problem, which is a smooth image of flexible processing using the difference algorithm between different pixels in the raw material. of. Its work is the center of the target texture, and the four pixel color values near this point are averaged, and then this average color value is passed to the position of the target image. By using double linear filtration, although the transition between different pixels is more sleek, the image after bilinear processing will appear blurred. Environment Mapped Bump Mapping: The surface of the object in the real world is not smooth, so it is necessary to reflect the uneven and pleats of the real object by concave convection simulation techniques. The traditional 3D graphics card is used to be embossed (EMBOS) effect approximately a convex and concave mapping. This relief effect is limited, it is difficult to show the reflective effect at a subtle angular angle and the effect in a complex multi-aerative light source, and it is more unable to show water waves. Effect of special fluids such as airflow. The environment mapping convex and concave map is to map a layer of texture on the standard surface texture, the texture is the same but the location is changed, and the displacement depth is determined by the depth information and the light source position, and then the lower texture is further processed as an upper layer according to the performance object. The textured shadow or bottom surface, which realizes the convex pleat effect of the surface of the real object.
Gouraud Shading: This is currently a more popular coloring method, which provides continuous color discs for each point on the polygon, which is rendered, and each polygon can use unlimited colors. It renders have extremely rich colors and smooth discoloration effects. MIP-MAPPING: MIP-mapping core feature is based on changes in the direction of the object's depth of field, and the MIP mapping is based on different sizes of material map according to different far, such as the large material of 512x512, and A smaller map is attached to the distal object. This can not only produce better visual effects, but also saves system resources. Phong Shading: This is the best, most complicated coloring method, and the effect is better than Gouraud Shading. Its advantage is to process the "mirror reflective", which gives each point on the model to the total strength value of the projected light, so the extremely high surface brightness can achieve the effect of "mirror reflectance". S3TL ("Transform and Lighting): This technology is similar to NVIDIA's latest T & L technology, which greatly reduces the geometric operation process of the CPU's 3D pipeline. The "Deformation and Light Source" engine can be used in future OpenGL and DirectX 7 graphics interfaces to increase the polygonal generation rate in the game to 4 to 10 times. This greatly alleviates the complexity of the software, and also maximizes the CPU's calculation, so for systems with slower CPU floating point, there can be high speed graphics Treatment ability. S3TC (S3 TEXTURE COMPRESSION) / DXTC / FXT1: S3TC is a texture compressed format proposed by S3 companies, with the aim of achieving a system bandwidth and improving efficacy. The S3TC is compressed, and the limited texture cache space is used to store more textures because it supports the 6: 1 compression ratio, so the 6m texture can be compressed to 1M in the material cache, so that the cache is saved. It also improves the display performance. DXTC and FXT1 are similar to S3TC, which are Microsoft and 3DFX development texture compression standards, although supported in Direct 6, but has not yet been supported by games, and FXT1 can provide more than S3TC High compression ratio, reaching 8: 1, and it will also be supported in the 3DFX version of Glide. T & L and Light Processing: This is a new type of technique studied by NVIDIA to improve the image quality. In the past graphics technology, in order to make the object image true, it has to increase the polygonal design, so It will result in a decrease in speed, and less polygons are used, and the picture is very rough. This T & L technology used in GeForce256 is characterized by further improving the degree of edge smoothness of the surface of the object without increasing the object polygon, making the image more realistic and accurate. In addition, the role of the light source has also been paid to: the traditional light source processing is more single, free, and the geforce 256 has powerful light source processing power, which supports 8 independent light sources on the hardware, plus GPU support, instant processing The light source will make the picture more vividly, which can generate a light source effect with reflective properties.
Trilinear Filtering: Three-line filtration is a combined overlap in mitigating or eliminating different combined grade texture transitions. It must be used in conjunction with double linear filtration and combined processing mapping. Three-linear filtration is obtained from two most similar LOD grade textures to obtain new pixel values by sampling in two most similar LOD grade textures, making the two different depth grades can be more smoothing. Because of this, triplet filtering must use two double linear filtration, which must calculate the value of 2x4 = 8 pixels. For many 3D acceleration, this requires the calculation time of their two clock cycles. W-Buffer: The role of W-buffer is similar to Z-buffer, but its range is smaller, and the accuracy is higher. It can process more detailed processing between different objects and the location of the same object part. Z-Buffer: This is a technique for processing 3D object depth information. It records the current Z coordinates of different objects and the same object. When coloring, the structure behind other objects is blamed, so that They are not displayed. The higher the number of digits used in z Bufer, the more accurate the depth value it can provide. Now the graphic chip supports 24bit Z-Buffer and adds 8Bit template buffer, called 32bit Z-Buffer. Display memory: Like the memory function on the motherboard, the memory is also used to store data, but it is stored in the display chip processing. 3D Display Card Save Differences in General Display Card Different in: 3D Display Card There is also a memory of texture data or z-buffer data, such as a 6M memory VOODOO I display card, where 2M memory is Used in the above use. Since the 3D application is increasing, and the requirements of high-resolution, high-colored deep graphics treatment, the requirements for memory is getting faster, from early DRAM, transition to EDO-DRAM, until now often see SDRAM and SGRAM, speed is getting faster and higher in performance. The memory of Figure 4 is SGRAM, pay attention to its four sides, very good difference; Figure 5 The memory is EDO-DRAM, and two-side leads are used as SDRAM. Distinguishment of EDO-DRAM and SDRAM to see the number above the memory, generally marked with "08", "10", "12" and other words are SDRAM, labeled "80", "70", "60", " Most of the words such as -6 "," - 7 "is EDO-DRAM. In addition to the above three common memory, there are more professional memory such as VRAM (Dual Port Video Memory), WRAM (Window Memory), RDRAM, Cacheram, etc., mostly used on graphics processing workstations. The size of the memory is not fixed, from a single 256k, 512K, 1M to a single strip 2m, so you don't only look at the number of memory chips to guess how much memory capacity on the display card. There are also some empty sockets on the old display card to expand the memory (such as the right map, there are already inserted in the outlet), we should pay attention to the memory speed set with the display card when expanding, such as the original memory is 80ns, newly expanded memory is also 80ns, so that you can fail after expansion. BIOS: Also known as "VGA BIOS", mainly used to store control programs between chip and drivers, and store information such as display card model, specification, manufacturer, factory delivery time. When you open your computer, you feed back these information onto the screen by displays a control program within the BIOS. Figure 6 is showing BIOS on 3 different display cards, which can be seen that the shape is not the same.
