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Far Cry geometry format lineage — FC1 .cgf chunked file → FC6 .xbg

Traced from the actual FC1 source tree (leaked FC 1.34, buildable VS2022 x64). FC1 stores 3D geometry in a chunked .cgf format whose architecture is the direct ancestor of the FC5/FC6 .xbg chunk chain.

Engine line​

CryENGINE1 (FC1, .cgf chunks) → Dunia (FC2) → Dunia 2 (FC3) → Disrupt/Dunia (WD + FC5/6, .xbg chunks)

FC1 chunked geometry format​

Defined in CryCommon/CryHeaders.h + ResourceCompiler/CryChunkedFile.{cpp,h} and ResourceCompiler/ChunkFileReader.{cpp,h}.

Chunk type enum​

enum ChunkTypes {
 ChunkType_ANY = 0,
 ChunkType_Mesh = 0xCCCC0000,
 ChunkType_Helper,
 ChunkType_VertAnim,
 ChunkType_BoneAnim,
 ChunkType_GeomNameList, // obsolete
 ChunkType_BoneNameList,
 ChunkType_MtlList, // obsolete
 ChunkType_MRM, // obsolete
 ChunkType_SceneProps,
 ChunkType_Light,
 ChunkType_PatchMesh, // not implemented
 ChunkType_Node,
 ChunkType_Mtl,
 ChunkType_Controller,
 ChunkType_Timing,
 ChunkType_BoneMesh,
 ChunkType_BoneLightBinding,
 ChunkType_MeshMorphTarget,
 ChunkType_BoneInitialPos,
 ChunkType_SourceInfo
};

Chunk header (versioned)​

struct CHUNK_HEADER_0623 { // VERSION = 0x0623
 ChunkTypes ChunkType;
 int ChunkVersion;
 int FileOffset;
};
struct CHUNK_HEADER_0744 { // VERSION = 0x0744, adds ChunkID
 ChunkTypes ChunkType;
 int ChunkVersion;
 int FileOffset;
 int ChunkID;
};
typedef CHUNK_HEADER_0744 CHUNK_HEADER;

Each chunk's desc struct is independently version-tagged, e.g. TIMING_CHUNK_DESC_0918 { enum {VERSION = 0x0918}; CHUNK_HEADER chdr; ... }.

Chunk read dispatch​

CryChunkedFile::addChunk* methods (addChunkTiming/Node/Light/Mesh/BoneMesh/ Material/BoneNameList/BoneAnim/BoneInitialPos/MeshMorphTarget/BoneLightBinding/ SceneProps) dispatch on CHUNK_HEADER.ChunkType, and the reader throws CryChunkedFile::Error on truncated/unknown chunks.

Resource Compiler (the offline toolchain ancestor)​

  • ResourceCompiler/ — CgfConvertor-adjacent plumbing: CryChunkedFile, ChunkFileReader, CryBoneDesc, CryBoneHierarchyLoader, CgfUtils, FileMapping, CfgFile, ExtensionManager.
  • ResourceCompilerPC/ — the x64 converter: CgfConvertor.cpp, CrySkinBase/Builder/BasisBuilder/Full/Morph (plus CrySkinAMD64.asm), Controller, CryAnimationInfo, BoneLightBindInfo.
  • ResourceCompilerImage/ — ImageCompiler, ImageObject, dds.h, neuquant (DDS/quantized texture compression).

This is the origin of Disrupt's ShaderCompiler2/ResourceCompiler architecture — the offline compile pipeline whose outputs the FC6 shadersobj.dat + .xbg files carry.

Archive system: .pak in FC1 (not .dat/.fat)​

FC1's VFS is CryPak (CrySystem/CryPak.cpp, ICryPak.h) reading .pak directory-file archives. There is no .dat/.fat hashed BigFile in FC1 — that store appears later in the Dunia line (FC2+). So the FAT2/BigFile v11 archive layout is a Dunia/Disrupt-era design, not FC1-origin. The .pak directory-file model is the conceptual ancestor of the .dat/.fat split (manifest + data), but the hashed key scheme is newer.

Mapping FC1 chunks → FC6 XBG chunks​

FC1 `.cgf` chunkFC6 XBG chunk (4CC)Role
`ChunkType_Mesh``SULC` (CLUS)cluster / submesh geometry
`ChunkType_Node``EDON` (NODE)node hierarchy
`ChunkType_Mtl``LTMR` (material ref)material list
`ChunkType_BoneNameList``DNKS` (SKND)bone names / skin data
`ChunkType_BoneAnim``ITOM` (MOTI)animation
`ChunkType_BoneMesh` / `MeshMorphTarget``KSRP` / `DIKS` (SKID)skinning / morph
`ChunkType_SourceInfo`header `HSEMI`/`HSEMG`file metadata

Same architecture — type-tagged, versioned chunk headers with IDs, read via a chunk-file reader with per-type dispatch. Only the magic changed: FC1 uses an int ChunkType enum in .cgf; FC6 uses 4CC markers in .xbg.

Open items​

  • FC6 .xbg SDOL descriptor extra-field semantics (the field-level decode the repo still tracks) — FC1's MESH_CHUNK_DESC/NODE_CHUNK_DESC layouts are a candidate reference for what those fields mean, worth comparing field-by-field.
  • FC6 sarb shader wrapper — no FC1/.cgf equivalent; a Disrupt/FC6-era packaging detail.