Special technical terms for 3D Design

Source: Internet
Author: User
This article Article Shader's understanding is helpful.

Mapping)

Texture Mapping)
It is the most noticeable and realistic method for object coloring, and most of them are used by current game software. A plane image (which can be a digital image, small icon, or dot matrix Bitmap) is pasted on a polygon. For example, in the development of racing games, this technology can be used to draw tires and car bodies.

MIP Mapping (MIP ing)
This material texture technology uses different versions of material pattern for texture based on different precision requirements. For example, when an object moves closer to the user,ProgramThe material pattern with a higher granularity and clarity will be attached to the object surface, so that the object shows a higher level and a more realistic effect. When the object is far away from the user, the program will paste a simple, low-definition material pattern, and thus improve the overall efficiency of graphics processing. The level of detail is a standard for coordinating the relationship between texture pixels and actual pixels. It is generally used in medium and low-end graphics cards.

Bump mapping)
This is a technology used to simulate a rough outer surface in a 3D scenario. Save the changes in depth to a Paster, and then perform standard blending Paster on the 3D model to obtain the Paster surface effect. Generally, this special effect is only supported by high-end display cards. (Note: geforce256 only supports displaying and calculating the effect, not generating special effects)

Video Texture Mapping)
This is currently the best texture effect. A graphic image accelerator card with this function uses a high-speed image processing method to process a continuous image (which may be an instant operation or an AVI or mpeg file) as a material, then paste it on the surface of a 3D object.

Texture map interpolation (material image filtering)
When a material is attached to a 3D model displayed on the screen, the material processor must determine the position of the pixel to which the element is attached. Because the material is a 2D image, and the model is a 3D object, the pixel range is usually not the same. In this case, we need to use interpolation to solve the problem of pixel textures.
There are three Processing Methods: "neighbor sampling", "dual-line filtering", "three-line filtering", and "Al filtering ".

1. Nearest Neighbor (neighbor sampling)
Also known as point sampling (point sampling), it is a processing method of simple material image interpolation. Uses a map with the largest number of pixels. In other words, the image is used to map the most pixels. This processing method is often used for early 3D game development because of its fast speed, but the quality of materials is poor.

2. bilinear interpolation (dual-line filtering)
This is a better way of processing material image interpolation. We will first find the four elements closest to the pixel, and then make a difference between them, the final result will be pasted to the position of the pixel, so that the "Mosaic" phenomenon will not be seen. This processing method is more suitable for static images with a certain depth of field, but cannot provide the best quality. The biggest problem is that when a 3D object becomes very small, a kind of object called depth aliasing artifacts (deep pseudo-sample sawtooth) is not applicable to moving objects.

3. trilinear interpolation (three-line filter)
This is a more complex method of texture image interpolation, which uses a considerable number of texture images, and the size of each image is exactly 1/4 of that of the other. For example, if a material image contains 512x512 elements, the second image will contain 256x256 elements, and the third image will contain 128x128 elements, in short, the smallest one is 1 × 1. With these multi-resolution texture images, high-quality texture effects can be provided in scenarios with a large depth of field (such as flight simulation. A "two-line filter" requires three Mixing Times, while a "three-line filter" requires seven Mixing Operations, so each pixel requires more than 21/3 times of computing time. It also requires two times the memory clock bandwidth. However, "three-line filtering" can provide the highest texture quality, which will remove the material's "flashing" effect. Only three-line filtering can provide acceptable material quality for scenarios that require a large amount of dynamic objects or depth of field.

4. Anisotropic interpolation (heterosexual filtering)
It takes 8 or more pixels for processing during sampling, and the quality is the best.

Shading)

The vast majority of 3D objects are made up of polygon. They must be colored before they are displayed in wire frame mode. These coloring methods are mainly divided into flat shading, Gouraud shading, phone shading, scanline Renderer, and Ray-traced.

Flat Shading)
It is also called "constant coloring". Plane coloring is the simplest and fastest coloring method. Each polygon will be specified with a single and unchanged color. Although this method produces unrealistic results, it is very suitable for fast imaging and other scenarios where the speed is more important than detail, such as generating preview animations.

Gouraud shading)
This coloring effect is much better, and it is also the most widely used coloring method in the game. It can smooth and combine the colors of vertices in the 3D model, assign each vertex on each polygon to a set of color values, and place the Polygon on a smoother gradient color, make its appearance more real-time and three-dimensional dynamic, but its coloring speed is much slower than that of plane coloring.

Phone Shading)
First, find out the vertices of each polygon, then calculate the Light and Shadow values of the pixels on the line between the vertices Based on the inner interpolation method, and then use linear interpolation again, calculate all the other pixels. during sampling and calculation, we only focus on the light and shade effects of each polygon vertex, but the complementary coloring will calculate all vertices.

Scanline Renderer (Scan Line coloring)
This is the default Rendering Method of 3DS MAX. It is a coloring method based on a set of continuous horizontal lines. Because of its fast rendering speed, it is generally used in preview scenarios.

Ray-traced (light tracing coloring)
Ray Tracing is a real projection of the object based on the incident path of the physical light, and the final reflection is returned to the camera to obtain the true color of each pixel.AlgorithmBecause of its accurate computing and high image quality, you must use this option to create CG.

Radiosity (radiation coloring)
This is a special effect similar to ray tracing. It calculates the light and shadow effects from the observer to the entire path of the light source based on the position and reflection of the object. On this line, light is affected by the interaction of different objects, such as reflection, absorption, and refraction.

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