Mipmapping (MIP texture)

This material texture technology uses different versions of material pattern for texture based on different precision requirements. For example, when an object is moved closer to the user, the program will attach a finer and higher-definition material pattern to the object surface, so that the object shows a higher and more real effect; when the object is far away from the user, the program will attach a simple, low-definition material pattern, and thus improve the overall efficiency of image 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.

Mipmapping is used to solve the sample routing problem. When the texture is mapped to a polygon and sampled (such as vertex sampling and bilinear texture filtering, there will be some strange phenomena related to the spatial information sampling theory. When two identical Repeated patterns (composed of straight lines, circles, or lattice) are combined, if they are not fully aligned, a ripple is formed. The ripple pattern is not inherent in the image, it is an illusion. This pattern usually appears in areas with a high contrast or a high frequency. When two images are combined, this pattern also appears due to mutual interference between the light area and the dark area.

To implement mipping, you need to create an MIP chain composed of textures. The size of each texture is 1/4 of that of the previous texture (halved along each axis ), the size of the last texture is 1x1.
In addition, these MIP texture chains are generated using filters (average filter, Box Filter, Gaussian filter, etc. When rendering a polygon, select an appropriate MIP texture based on the distance between the polyon and the viewpoint or the area after the polyon is projected. In this way, the problem of flickering and low frequency variation will be minimized.