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 Homeworld File Format Documentation .GEO File Format By B1FF (lmoloney@relic.com) © 2000 Relic Entertainment, Inc. Preamble The .GEO file format is used to store all geometry for Homeworld. It's a pretty simple format but stores complex data. It is tightly integrated with the .LiF file format and even refers to the name of the .LiF textures. .GEO files use a right-handed coordinate space. Positive Z is the axis of travel for the spacecraft and positive X is the right wing. File Header Like other Homeworld file formats, there is a header chunk. typedef struct tagGeoFileHeader { char identifier[MESH_FileIDLength]; // File identifier. udword version; // File version. char *pName; // Offset to a file name. udword fileSize; // File size (in bytes), not counting this header. udword localSize; // Object size (in bytes). udword nPublicMaterials; // Number of public materials. udword nLocalMaterials; // Number of local materials. udword oPublicMaterial; //list of public materials udword oLocalMaterial; //list of local materials udword nPolygonObjects; // Number of polygon objects. ubyte reserved[24]; // Reserved for future use. } GeoFileHeader; Identifier: length of 8, value "RMF99ba". Version: 0x00000402 PName - offset to mesh name FileSize - not used LocalSize - only used at load time. N[Public | Local]Materials - add together to number of materials in mesh. OLocalMaterial - offset to material list. NPolygonObjects - number of elements in object. Reserved - reserved dag nabbit! Structure of a material typedef struct tagmaterialentry { char *pName; // Offset to name of material (may be a CRC32). color ambient; // Ambient color information. color diffuse; // Diffuse color information. color specular; // Specular color information. real32 kAlpha; // Alpha blending information. udword texture; // Pointer to texture information (or CRC32). uword flags; // Flags for this material. ubyte nFullAmbient; // Number of self-illuminating colors. bool8 bTexturesRegistered; // Set to TRUE when texture registered. char *textureNameSave; // After the texture has been registered } materialentry; pName - offset to material name ambient, diffuse, specular - lighting properties. KAlpha - not used Texture - offset to texture name. This is the name of a .LiF file without the path or extension. Flags - bit flags of the following: #define MDF_Smoothing 2 #define MDF_AllowFlatShading 4 #define MDF_2Sided 8 #define MDF_BaseColor 16 #define MDF_StripeColor 32 #define MDF_SelfIllum 64 Everything else: used internally Structure of a polygonObject typedef struct polygonobject { char *pName; // Name for animation. ubyte flags; // General flags (see above) ubyte iObject; // fixed up at load time so we know what object index we have when recursively processing uword nameCRC; // 16-bit CRC of name sdword nVertices; // Number of vertices in vertex list for this object. sdword nFaceNormals; // Number of face normals for this object. sdword nVertexNormals; // Number of vertex normals for this object. sdword nPolygons; // Number of polygons in this object. vertexentry *pVertexList; // Offset to the vertex list in this object. normalentry *pNormalList; // Offset to the normal list in this object. polyentry *pPolygonList; // Offset to the polygon list in this object. struct polygonobject *pMother; // link to parent object struct polygonobject *pDaughter; // link to child object struct polygonobject *pSister; // link to sibling object hmatrix localMatrix; } polygonobject; pName - offset to mesh name. Used for binding to animations. Flags, iObject, nameCRC - used internally. NVertices - number of vertices NFaceNormals, nVertexNormals, nPolygons - can you guess? PVertexList, pNormalList, pPolygonList - offsets to respective primitive lists. PMother, pDaughter, pSister - 2-dimentsional linked list of hierarchy. Feel the estrogen flow! LocalMatrix - 4x4 matrix (right-handed) that defines the objects's default position from the identity matrix. Structure of vertices and normals. These formats are nearly the same: typedef struct tagvertex { real32 x; // X component of this vertex. real32 y; // Y component of this vertex. real32 z; // Z component of this vertex. sdword iVertexNormal; // Index into the point normal list. } vertexentry; typedef struct tagnormal { real32 x; // X component of this normal. real32 y; // Y component of this normal. real32 z; // Z component of this normal. ubyte pad[4]; // Reserved for later use. } normalentry; iVertexNormal is the index of the normal for this vertex if there is one or 0xffffffff if there is none. Pad can be ignored. Structure of polygons typedef struct tagpolygon { sdword iFaceNormal; // Index into the face normal list. uword iV0; // Index to V0 of the polygon. uword iV1; // Index to V1 of the polygon. uword iV2; // Index to V2 of the polygon. uword iMaterial; // Index into material list. real32 s0; real32 t0; real32 s1; real32 t1; real32 s2; real32 t2; uword flags; // Flags for this polygon. ubyte reserved[2]; } polyentry; iFaceNormal is the index in the normal list of the face normal. IV[0..2] is the index in the vertex list of the plygon vertices Immaterial is the material this ply uses. [s | t][0..2] are the s/t coordinates (of the range 0..1) of the vertices in the texture map of the material. Flags - used internally. Reserved[0] - set to greater than 1. Reserved[1] - used internally for paco fixups. Don't ask. It's a world of hurt! |
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