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This article mainly shows you "what is the meaning of LOD in the secondary development of TE", the content is easy to understand, clear, hope to help you solve your doubts, the following let the editor lead you to study and learn "what is the meaning of LOD in the secondary development of TE"?

In the data production process of skyline, the data of the three-dimensional model is made into unique xpl2 and xpl formats, and when the model is relatively large, the model will be divided into several files. Except for the first xpl file, the other naming rules are: model name _ LOD_X, which is multiple LOD files generated according to the rules.

LOD technology is the abbreviation of Levels of Detail, meaning multiple levels of detail. LOD technology means that according to the position and importance of the nodes of the object model in the display environment, determine the resource allocation of object rendering, reduce the number of faces and details of non-important objects, so as to obtain efficient rendering operations.

In 1976, Clark put forward the concept of Levels of Detail (LOD) model. He thought that when an object covers a small area of the screen, the object can be used to describe a thicker model, and a geometric hierarchical model for the visible decision algorithm is given for fast rendering of complex scenes. --

According to the above, the model file is made into a LOD file at different levels. At the low level of the model, the rougher model is shown. Because it is far away, it will not have a great impact on the vision. When it is close to the position near the model, it shows a high-precision model, which greatly improves the display speed of the model and reduces the pressure on the system.

In 3dml, the lod model of xpl2 will be merged according to certain similar areas, that is, the rough model will be merged to a certain extent, which can compress the amount of data of the whole model, reduce the number of rendering of the model, and then be separated with the index of Quadtrees, and dynamically show and hide different levels of models with the display range of the map, so as to reduce the share of the model to system resources. Speed up browsing of the model.

In the 3dtile production of Cesium, also follow this principle, the specific algorithm can be found on the Internet, most of the code is C++.

The above is all the contents of the article "what does LOD mean in the secondary development of TE?" Thank you for reading! I believe we all have a certain understanding, hope to share the content to help you, if you want to learn more knowledge, welcome to follow the industry information channel!

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