2.LOD technology refers to determining the position and importance of nodes in the display environment according to the object model.

3. Usually, several geometric models with different approximate accuracy are established for each original polyhedron model. Compared with the original model, each model retains a certain degree of detail. When drawing, choose an appropriate hierarchical model to represent objects according to different standards.

4.LOD technology is widely used. At present, it has been applied to real-time image communication, interactive visualization, virtual reality, terrain representation, flight simulation, collision detection, time-limited graphics rendering and other fields, and has become a key technology. Many modeling software and VR development systems have begun to support LOD model representation.

Extended data:

China's standards are AU9999, AU9995, AU999 and AU995; ; Specifications are 50g, 100g, 1kg, 3kg,12.5kg. ..

Japanese standard gold requires purity of 99.99% and weight 1 kg.

Non-standard gold: gold that does not meet the above standards.

Any kind of gold products should be marked with information such as purity and alchemy factory. The usual representation is to express the gold content as a percentage. There is also a representation that divides the gold content into 10000 parts by weight. For example, if there is 9999 on the gold sheet, it means that the gold content of the gold sheet is 99.99%, and if there is a mark of 586 on the gold sheet, it means that the gold sheet contains 58.6%.

"K" is often used to indicate the fineness of gold in jewelry, gold pen manufacturing and other industries. According to the national standard GB 1 1887-89, the gold content of each opening (abbreviation for carat in English, karat in German, often written as "K") is 4. 166%. Therefore, the gold content of each opening is (GB in brackets):

Extended source: Baidu Encyclopedia-Gold fineness