MD2文件由两个主要部分组成：文件头和数据。
文件头部分： 包含模型描述，多边形数，顶点数和动画细节等。
数据部分： 组成模型的多边形网格的数据，包括所有的多边形，顶点和纹理数据。
在MD2文件中，所有的多边形都为三角形，且没有其他的实体。
顶点数据定义的不是单帧而是多帧动画。事实上，每个MD2文件包含198帧动画，编号为0－197。
MD2文件头数据结构定义：
// This is the header structure for a Quake II .MD2 file by id Software
typedef struct MD2_HEADER_TYPE
{
int identifier; // identifies the file type, should be "IDP2"
int version; // version number, should be 8.
int skin_width; // width of texture map used for skinning
int skin_height; // height of texture map used for skinning
int framesize; // number of bytes in a single frame of animation
int num_skins; // total number of skins,
// listed by ASCII filename and are available for loading if files are found in full path.
int num_verts; // number of vertices in each model frame,
// the number of vertices in each frame is always the same.
int num_textcoords; // total number of texture coordinates in entire file,
// may be larger than the number of vertices.
int num_polys; // number of polygons per model, or per frame of animation if you will.
int num_openGLcmds; // number of openGL commands which can help with rendering optimization,
// however, we won't be using them.
int num_frames; // total number of animation frames
// memory byte offsets to actual data for each item
int offset_skins; // offset in bytes from beginning of file to the skin array that holds the file name
// for each skin, each file name record is 64 bytes.
int offset_textcoords; // offset in bytes from the beginning of file to the texture coordinate array
int offset_polys; // offset in bytes from the beginning of file to the polygon mesh
int offset_frames; // offset in bytes from the beginning of file to the vertex data for each frame
int offset_openGLcmds; // offset in bytes from the beginning of file to the openGL commands
int offset_end; // offset in bytes from the beginning of file to end of file
} MD2_HEADER, *MD2_HEADER_PTR;
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