Convert mesh to x

What is the difference between .mesh and .x?

Description: Mesh is a 3D graphic data file type that contains information about the surface of a 3D object. It is composed of vertices, edges, and faces that define the shape and structure of the object. Mesh files can be used to create 3D models for computer graphics and animation.; X is a DirectX Model image file used by DirectX technology which is for 3D graphics rendering in games. The file format specifies 3D object structures for meshes, textures, animations, and objects.