This is a description of the file formats and structures used by The Sims character animation system, by Don Hopkins.

CMX File:

• int32 skeletoncount;
• skeleton skeletons[skeletoncount];
• int32 suitcount;
• suit suits[suitcount];
• int32 skillcount;
• skill skills[skillcount];

Skeleton:

• countedstring name;
• int32 bonecount;
• bone bones[bonecount];

Bone:

• countedstring name;
• countedstring parentname;
• int32 hasprops;
• ? props prop;
• float trans[3];
• float rot[4];
• int32 cantranslate;
• int32 canrotate;
• int32 canblend;
• int32 canwiggle;
• int32 wigglepower;

Skill:

• countedstring name;
• countedstring filename; [of compressedfloatingpoint file]
• float duration;
• float distance;
• int32 ismoving;
• int32 numtranslations;
• int32 numrotations;
• int32 motioncount;
• motion motions[mountcount];

Motion:

• countedstring bonename;
• int32 frames;
• float duration;
• int32 hastranslation;
• int32 hasrotation;
• int32 translationsoffset;
• int32 rotationsoffset;
• int32 hasprops;
• ? props props;
• int32 hastimeprops;
• ? timeprops timeprops;

Suit:

• countedstring name;
• int32 type;
• int32 hasprops;
• ? props prop;
• int32 skincount;
• skin skins[skincount];

Skin:

• countedstring bonename;
• countedstring name; [of deformablemesh file]
• int32 flags;
• int32 hasprops;
• ? props prop;

PropsKeyValue:

• countedstring key;
• countedstring value;

Props:

• int32 size;
• propskeyvalue keyvalues[size];

TimePropsKeyValue:

• int32 key;
• props value;

TimeProps:

• int32 size;
• timepropskeyvalue keyvalues[size];

CountedString:

• byte len;
• (len == 255)
• ? int32 len;
• : char string[len];

DeformableMesh:

• countedstring filename;
• countedstring texturename;
• int32 bonecount;
• countedstring bonenames[bonecount];
• int32 facecount;
• deformableface faces[facecount];
• int32 bonebindingcount;
• bonebinding bonebindings[bonebindingcount];
• int32 texturevertexcount;
• texturevertex texturevertices[texturevertexcount];
• int32 blenddatacount;
• blenddata blenddata[blenddatacount];
• int32 vertexcount;
• normalvertex vertices[vertexcount];

DeformableFace:

• int avertexindex;
• int bvertexindex;
• int cvertexindex;

BoneBinding:

• int boneindex;
• intfirstvert;
• int vertcount;
• int firstblendedvert;
• int blendedvertcount;

TextureVertex:

• float u;
• float v;

BlendData:

• int32 weightfixed;
• int32 othervertexindex;

NakedVertex:

• float x;
• float y;
• float x;

NormalVertex:

• nakedvertex naked;
• nakedvertex norm;