This is the 3D Model File Format used in SILENT HILL 2. It's mostly been reverse engineered by Mike M (the creator of the Silent Hill 2 Level Viewer). Most of the on disk structures have been identified and reverse engineered to the point where it is possible to draw a model in its entirety, as well as animate it, if it contains animations. Most of this work was done by Mike M (perdedork), the creator of the Silent Hill Level Viewer. Further reversing and confirmation was done by myself and Kneesnap. The file contains all mesh data required to draw the model correctly in-engine, including but no limited to: skeleton/bone data (including vertex weights), Blinn-Phong lighting data, index/face data, embedded textures etcetera.
Note1: There is a significant difference between the PS2 and PC versions of this file format. The PS2 version seems to be tightly coupled to the Playstation's Vector Units, with symbols dumped from the E3 Trial Version containing data members such as vu0_parts_offset, implying that the model format was designed to be DMA'd straight to the GS.
Note2: Some of the member names in this document are names from SH2 DWARF2 symbols, and hence may be slightly wonky or not quite make sense.
.mdl- 1
Model3_FileHeader - 1
Model3_ModelHeader - 1
Model3_VertexOffsetHeader - 1-n
Initial Matrices - 1-n
Skeletons - 1-n
Primitive Descriptor Block(???) - 1
Index Data Block - 1
Vertex Data Block - 0-n
Textures
- 1
| Type | Name | Offset | Comment |
|---|---|---|---|
| u4 | unknown1 | 0x00 | Called "NoTextureID" on the PS2 Version. |
| u4 | character_id | 0x04 | Internal ID used by engine for this model |
| u4 | number_of_textures | 0x08 | |
| u4 | texture_header_offset | 0x0C | Offset to (first) texture header |
| u4 | model_header_offset | 0x10 | Offset to model data header |
| u4 | kg1_data_offset | 0x14 | Embedded KG1 data. Doesn't look like this is used to often |
NOTE: All offsets are relative to the beginning of THIS header!
| Type | Name | Offset | Comment |
|---|---|---|---|
| u4 | header_magic | 0x00 | Always 0xffff0003 |
| u4 | model_version | 0x04 | Model3 version number. 0x03 for PS2, 0x04 for PC |
| u4 | initial_matrices_offset | 0x08 | Initial pose matrices(???). See image below in the "Research" section of this file |
| u4 | number_of_skeletons | 0x0C | Number of skeletons in this model. Seems to line up with the the number of initial_matrices |
| u4 | skeleton_data_offset | 0x10 | |
| u4 | number_of_skeleton_pairs | 0x14 | ??? |
| u4 | skeleton_pairs_offset | 0x18 | |
| u4 | default_pcms_offset | 0x1C | ??? |
| u4 | number_of_primitive_headers | 0x20 | Seems to be the number of main vertex primitive headers |
| u4 | primitive_headers_offset | 0x24 | |
| u4 | number_of_primitive_headers_b | 0x28 | Mike has this marked as "alt_vert_sects". Not sure what that means yet |
| u4 | primitive_headers_offset_b | 0x2C | |
| u4 | number_of_texture_blocks | 0x30 | |
| u4 | texture_block_offset | 0x34 | |
| u4 | number_of_texture_ids | 0x38 | |
| u4 | texture_id_offset | 0x3C | |
| u4 | texture_id_param_offset | 0x40 | This seems to point to a copy of this header on the PC version |
| u4 | number_of_cluster_nodes | 0x44 | Name from PS2. Not sure what a "cluster node" is yet. Quaternion/Rotation data? |
| u4 | cluster_nodes_offset | 0x48 | |
| u4 | number_of_clusters | 0x4C | Same as above |
| u4 | clusters_offset | 0x50 | |
| u4 | unknown1 | 0x54 | Called number_of_function_data on PS2 version |
| u4 | unknown2 | 0x58 | Called offset_to_function-data on PS2 version |
| u4 | unknown3 | 0x5C | Called hit_offset on PS2 version |
| u4 | unknown4 | 0x60 | Called box_offset on PS2 version |
| u4 | unknown5 | 0x64 | Called flag on PS2 version |
| u4 | unknown6 | 0x68 | Called relative_matrices_offset on PS2 version |
| u4 | unknown6 | 0x6C | Called relative_transpositions_offset on PS2 version |
| u4 | unused4 | 0x70-0x80 |
| Type | Name | Offset | Comment |
|---|---|---|---|
| u4 | vertex_count | 0x00 | Number of vertices |
| u4 | vertex_data_offset | 0x04 | Offset to vertex data relative to Model3_ModelHeader |
| u4 | unknown1 | 0x08 | |
| u4 | unknown2 | 0x0C | |
| u4 | index_data_offset | 0x10 | Offset to index data relative to Model3_ModelHeader |
| u4 | unknown3 | 0x14 | |
| u4 | unknown4 | 0x18 | |
| u4 | unknown5 | 0x1C | |
| u4 | unknown6 | 0x20 |
No idea how this is laid out yet. Looks to be like some kind of node-tree or linked list. All values look 16-bit. First value always seems to be 0xFF
This data type is varying in size, and describes the different "Vertex Parts" of the model. I'm not entirely sure of the exact purpose and layout of these, as Mike's code doesn't really describe too much. I've managed to reverse the structure somewhat, in terms of how to actually read it into memory.
| Type | Name | Offset | Comment |
|---|---|---|---|
| u4 | header_size | 0x00 | Size of this header. Usually at least 0xB0 bytes long |
| u4 | pad1 | 0x04 |
| Type | Name | Offset | Comment |
|---|---|---|---|
| u4 | unknown_count_1 | 0x00 | Looks to be some kind of count for 16-bit data |
| u4 | offset_to_unknown_count_1 | 0x04 | |
| u4 | unknown_count_2 | 0x08 | Looks to be some kind of count for 16-bit data |
| u4 | offset_to_unknown_count_2 | 0x0C | |
| u4 | unknown_count_3 | 0x10 | Looks to be some kind of count for 16-bit data |
| u4 | offset_to_unknown_count_3 | 0x14 | |
| u4 | offset_to_footer_marker | 0x18 | Offset to the magic number 0x02020303 which signifies the end of this header |
There is more data contained within this header, however it's currently unknown. Offset 0x78 and 0x80 looks like start offset of indices and number of indices (all 16-bit) for the given section
See tex.md (WIP)