回答:
エクスポーターを作成します。いや、本当に。
これにより、必要なデータを必要な形式で正確に出力できます。
既存のプラグインの1つから始めると、実際には非常に簡単です。
私は常にOBJファイルを解析するのが最も簡単だと思っていましたが、「人間が読める」ため、サイズが大きくなる傾向があります。ただし、それらは公開され、標準化されています。
必要な場合は、Obj仕様：
もちろん、.objは解析が最も簡単ですが、（アニメーションを使用して）もう少し強力なものが必要な場合は、.md2ファイル形式を取得します。
高校のコードをいくつか掘り下げることができれば、私が書いたmd2ローダーを見つけることができるかもしれません。
Milkshape（MS3D）形式は、C ++およびC＃でリーダーを実装するのが非常に簡単でした。これが私が使用した仕様です（web.archive.orgから取得）：
//
//
//
// MilkShape 3D 1.8.2 File Format Specification
//
//
// This specifcation is written in C style.
//
//
// The data structures are defined in the order as they appear in the .ms3d file.
//
//
//
//
//
//
// max values
//
#define MAX_VERTICES 65534
#define MAX_TRIANGLES 65534
#define MAX_GROUPS 255
#define MAX_MATERIALS 128
#define MAX_JOINTS 128
//
// flags
//
#define SELECTED 1
#define HIDDEN 2
#define SELECTED2 4
#define DIRTY 8
//
// types
//
#ifndef byte
typedef unsigned char byte;
#endif // byte
#ifndef word
typedef unsigned short word;
#endif // word
// force one byte alignment
#include <pshpack1.h>
//
// First comes the header (sizeof(ms3d_header_t) == 14)
//
typedef struct
{
char id[10]; // always "MS3D000000"
int version; // 4
} ms3d_header_t;
//
// Then comes the number of vertices
//
word nNumVertices; // 2 bytes
//
// Then come nNumVertices times ms3d_vertex_t structs (sizeof(ms3d_vertex_t) == 15)
//
typedef struct
{
byte flags; // SELECTED | SELECTED2 | HIDDEN
float vertex[3]; //
char boneId; // -1 = no bone
byte referenceCount;
} ms3d_vertex_t;
//
// Then comes the number of triangles
//
word nNumTriangles; // 2 bytes
//
// Then come nNumTriangles times ms3d_triangle_t structs (sizeof(ms3d_triangle_t) == 70)
//
typedef struct
{
word flags; // SELECTED | SELECTED2 | HIDDEN
word vertexIndices[3]; //
float vertexNormals[3][3]; //
float s[3]; //
float t[3]; //
byte smoothingGroup; // 1 - 32
byte groupIndex; //
} ms3d_triangle_t;
//
// Then comes the number of groups
//
word nNumGroups; // 2 bytes
//
// Then come nNumGroups times groups (the sizeof a group is dynamic, because of triangleIndices is numtriangles long)
//
typedef struct
{
byte flags; // SELECTED | HIDDEN
char name[32]; //
word numtriangles; //
word triangleIndices[numtriangles]; // the groups group the triangles
char materialIndex; // -1 = no material
} ms3d_group_t;
//
// number of materials
//
word nNumMaterials; // 2 bytes
//
// Then come nNumMaterials times ms3d_material_t structs (sizeof(ms3d_material_t) == 361)
//
typedef struct
{
char name[32]; //
float ambient[4]; //
float diffuse[4]; //
float specular[4]; //
float emissive[4]; //
float shininess; // 0.0f - 128.0f
float transparency; // 0.0f - 1.0f
char mode; // 0, 1, 2 is unused now
char texture[128]; // texture.bmp
char alphamap[128]; // alpha.bmp
} ms3d_material_t;
//
// save some keyframer data
//
float fAnimationFPS; // 4 bytes
float fCurrentTime; // 4 bytes
int iTotalFrames; // 4 bytes
//
// number of joints
//
word nNumJoints; // 2 bytes
//
// Then come nNumJoints joints (the size of joints are dynamic, because each joint has a differnt count of keys
//
typedef struct // 16 bytes
{
float time; // time in seconds
float rotation[3]; // x, y, z angles
} ms3d_keyframe_rot_t;
typedef struct // 16 bytes
{
float time; // time in seconds
float position[3]; // local position
} ms3d_keyframe_pos_t;
typedef struct
{
byte flags; // SELECTED | DIRTY
char name[32]; //
char parentName[32]; //
float rotation[3]; // local reference matrix
float position[3];
word numKeyFramesRot; //
word numKeyFramesTrans; //
ms3d_keyframe_rot_t keyFramesRot[numKeyFramesRot]; // local animation matrices
ms3d_keyframe_pos_t keyFramesTrans[numKeyFramesTrans]; // local animation matrices
} ms3d_joint_t;
//
// Then comes the subVersion of the comments part, which is not available in older files
//
int subVersion; // subVersion is = 1, 4 bytes
// Then comes the numer of group comments
unsigned int nNumGroupComments; // 4 bytes
//
// Then come nNumGroupComments times group comments, which are dynamic, because the comment can be any length
//
typedef struct
{
int index; // index of group, material or joint
int commentLength; // length of comment (terminating '\0' is not saved), "MC" has comment length of 2 (not 3)
char comment[commentLength]; // comment
} ms3d_comment_t;
// Then comes the number of material comments
int nNumMaterialComments; // 4 bytes
//
// Then come nNumMaterialComments times material comments, which are dynamic, because the comment can be any length
//
// Then comes the number of joint comments
int nNumJointComments; // 4 bytes
//
// Then come nNumJointComments times joint comments, which are dynamic, because the comment can be any length
//
// Then comes the number of model comments, which is always 0 or 1
int nHasModelComment; // 4 bytes
//
// Then come nHasModelComment times model comments, which are dynamic, because the comment can be any length
//
// Then comes the subversion of the vertex extra information like bone weights, extra etc.
int subVersion; // subVersion is = 2, 4 bytes
// ms3d_vertex_ex_t for subVersion == 1
typedef struct
{
char boneIds[3]; // index of joint or -1, if -1, then that weight is ignored, since subVersion 1
byte weights[3]; // vertex weight ranging from 0 - 255, last weight is computed by 1.0 - sum(all weights), since subVersion 1
// weight[0] is the weight for boneId in ms3d_vertex_t
// weight[1] is the weight for boneIds[0]
// weight[2] is the weight for boneIds[1]
// 1.0f - weight[0] - weight[1] - weight[2] is the weight for boneIds[2]
} ms3d_vertex_ex_t;
// ms3d_vertex_ex_t for subVersion == 2
typedef struct
{
char boneIds[3]; // index of joint or -1, if -1, then that weight is ignored, since subVersion 1
byte weights[3]; // vertex weight ranging from 0 - 100, last weight is computed by 1.0 - sum(all weights), since subVersion 1
// weight[0] is the weight for boneId in ms3d_vertex_t
// weight[1] is the weight for boneIds[0]
// weight[2] is the weight for boneIds[1]
// 1.0f - weight[0] - weight[1] - weight[2] is the weight for boneIds[2]
unsigned int extra; // vertex extra, which can be used as color or anything else, since subVersion 2
} ms3d_vertex_ex_t;
// Then comes nNumVertices times ms3d_vertex_ex_t structs (sizeof(ms3d_vertex_ex_t) == 10)
// Then comes the subversion of the joint extra information like color etc.
int subVersion; // subVersion is = 2, 4 bytes
// ms3d_joint_ex_t for subVersion == 1
typedef struct
{
float color[3]; // joint color, since subVersion == 1
} ms3d_joint_ex_t;
// Then comes nNumJoints times ms3d_joint_ex_t structs (sizeof(ms3d_joint_ex_t) == 12)
// Then comes the subversion of the model extra information
int subVersion; // subVersion is = 1, 4 bytes
// ms3d_model_ex_t for subVersion == 1
typedef struct
{
float jointSize; // joint size, since subVersion == 1
int transparencyMode; // 0 = simple, 1 = depth buffered with alpha ref, 2 = depth sorted triangles, since subVersion == 1
float alphaRef; // alpha reference value for transparencyMode = 1, since subVersion == 1
} ms3d_model_ex_t;
#include <poppack.h>
//
// Mesh Transformation:
//
// 0. Build the transformation matrices from the rotation and position
// 1. Multiply the vertices by the inverse of local reference matrix (lmatrix0)
// 2. then translate the result by (lmatrix0 * keyFramesTrans)
// 3. then multiply the result by (lmatrix0 * keyFramesRot)
//
// For normals skip step 2.
//
//
//
// NOTE: this file format may change in future versions!
//
//
// - Mete Ciragan
//