Resource identity and name hashes

Frostbite uses different keys for different registries. Equality in one registry does not imply equality in the others: a mesh’s manifest name, resource id and stored name hash are separate fields. Observed

Registry	Identity and constraint	Confidence
Bundle resource entry	Name, 32-bit type id, 64-bit resource id	Observed
EBX external reference	File GUID plus instance GUID	Observed
EBX name resolution	One name must identify one partition in the measured level closure	Observed
Mesh resolution	One MeshSet name must identify one resource id across the loaded compartments	Observed
Renderer material-owner cache	Stored 32-bit mesh name hash; strings are not compared	Observed
Texture streamer	h64, one mip-chunk GUID per identity within a level	Observed
ShaderBlockDepot registry	One material key must identify one parameter block across loaded cells	Observed

Mesh name hashes

The mesh hash is djb2-XOR over the lowercase full resource path: start with 5381, then h = (h * 33) XOR c with 32-bit wrapping. MeshAsset stores it at +0xc8; MeshSet also stores a name hash at +0x78 and hashes for LOD names. Renaming only the manifest entry leaves these cached identities unchanged. Observed

The material-owner cache (Skate+0x3f56860) and resource-name resolution (+0x3db78d0) compare hashes only, never strings. The cache constructs its key from a mesh name hash in the upper 32 bits and a second 32-bit value from the material entry. Its 0x58-byte owner stores the slot table at +0x20 and count at +0x28. Two different paths with the same hash can therefore reuse a slot table of the wrong size. Observed

In a partial census of 241,857 names, seven hashes collide; the base-name subset has one collision among 101,590 names. Identical suffixes preserve a djb2-XOR collision, so adding _lod0 to both colliding paths cannot separate their hashes. Observed

For a level of about 50,000 generated mesh names, the chance of at least one 32-bit collision is about 25%, by the birthday bound. Inferred

The same recurrence hashes lowercase resource type names, including MeshSet 0x49b156d4, Texture 0x6bde20ba and ShaderBlockDepotResource 0x73312045. These type ids are not resource-instance ids. Observed

Resource types in stock

The 6,056 stock manifests list 428,211 resource entries of 47 distinct type ids. 26 of the ids are the djb2-XOR hash of a lowercase type name, found by hashing the type names, field names and strings of the stock EBX documents and a list of candidate class names (the same recurrence as the mesh hash above); the other 21 ids have no name yet. Observed · hashes of 303,105 distinct strings against the 47 ids

Type id	Name	Resources	Top path directories
0x7dd4cc89		116,213	gameplay/, ui/
0x6bde20ba	Texture	78,566	world/, characters/
0x49b156d4	MeshSet	49,414	world/, levels/
0xb2c465f6		34,982	audio/
0x4088bf7e		34,088	animation/
0x41759364	PhysicsResource	33,277	world/, levels/
0xd489facb	ExpressionShaderRasterPermutation	28,151	expressionshader/
0x0e2b02f7	CompiledBytecode	20,429	shaders/
0x93afacc3		7,654	ui/, thumbnail/
0x5297a88f		6,784	audio/, frsr/
0x250047b2	ExpressionShaderRasterPermutationSharedData	4,533	expressionshader/
0xed27dbda		3,026	characters/
0x2fec6526	ShaderStateAssetId	2,598	levels/, items/
0x73312045	ShaderBlockDepotResource	2,490	levels/, items/
0xa19b025d	ExpressionShaderBindingSet	1,198	expressionshader/
0x78791c75		900	effects/
0xf17ddabd		804	e23f05da-92dc-74dd-fe26-b1912244b73e_scalphair_wraplist_deformsettinge23f05da-92dc-74dd-fe26-b1912244b73e_scalphair_wraplist_deformsetting_wrap[4][4][0]/, e23f05da-92dc-74dd-fe26-b1912244b73e_scalphair_wraplist_deformsettinge23f05da-92dc-74dd-fe26-b1912244b73e_scalphair_wraplist_deformsetting_wrap[1][1][1]/
0x7a630735	ExpressionShaderStreamableTextureSet	477	expressionshader/
0x7d98f632	ExpressionShaderInputLayout	476	expressionshader/
0xaa8c66b5		471	audio/
0x30b4a553	OccluderMesh	442	world/
0xa8957ed6	ExpressionShaderRootSlotInitData	381	expressionshader/
0x95ce62dd	ExpressionShaderComputePermutation	242	expressionshader/
0x879ba711	ExpressionShaderPermutationSharedData	102	expressionshader/
0x063994c5		82	ui/
0xe2e6955b	ExpressionShaderDatabase	72	effects/, levels/
0x2d254a89	ExpressionShaderStreamableTextureSetLookupTable	72	effects/, levels/
0x85ea8656		60	characters/
0x85ac783d		60	characters/
0x8ef3938d		42	characters/
0xec383b87		30	characters/
0xde540c59	LayerGraphs	22	gameplay/, items/
0xf434940d	ShaderParameterCollectionTable	9	common/, effects/
0x70c5cb3e		9	levels/, lighting/
0x428ec9d4	BundleRefTableResource	8	common/, audio/
0x589bb36e	ExpressionShaderPassBinding	7	expressionshader/
0xc631492b		7	characters/
0x41d57e10		7	ui/
0x6a5be5db	ExpressionShaderBindingSignature	5	expressionshader/
0x22fe8ac8	TerrainStreamingTree	4	levels/
0x1ca38e06	VisualTerrain	4	levels/
0x15e1f32e	TerrainDecals	4	levels/
0x957c32b1	AtlasTexture	3	lighting/
0x89983f10		2	ui/
0xc189b12b		2	effects/
0xf04f0c81		1	systems/
0xb15ad3fd		1	levels/

A texture resource’s 64-bit streaming identity also carries this hash: its low 32 bits are the djb2-XOR hash of the texture’s lowercase resource name in all 61,618 distinct stock texture headers (see texture resources). Proven · all stock texture resources

Textures and depots

A texture’s h64 appears at resource +0x78 and in its bundle chunk-metadata row. Base-game per-cell copies of the same streamed texture share a mip chunk; registering different chunks under one h64 causes a seam stall and failure. Observed

Base-game material keys can appear in several depots with identical blocks. A measurement of 9,306 repeated keys finds no conflicting block hashes. Registering a key with different blocks can leave a freed parameter box in the registry. Observed

The distinct mesh failures and their measured corrections are recorded in the crash catalogue.