OBD:M3GM: Difference between revisions
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Revision as of 12:17, 9 September 2007
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| Offset | Type | Raw Hex | Value | Description |
|---|---|---|---|---|
| 0x00 | res_id | 01 D7 00 00 | 215 | 00215-door_1_0.M3GM |
| 0x04 | lev_id | 01 00 00 00 | 3 | level 3 |
| 0x08 | int32 | 00 00 00 00 | 0 | runtime pointer? |
| 0x0C | PNTA | 01 DA 00 00 | 218 | link to vertex XYZs: 00218-.PNTA |
| 0x10 | VCRA | 01 F7 00 00 | 247 | link to vertex normals: 00247-.VCRA |
| 0x14 | VCRA | 01 F0 00 00 | 240 | link to face normals: 00240-.VCRA |
| 0x18 | TXCA | 01 ED 00 00 | 237 | link to vertex UVs: 00237-.TXCA |
| 0x1C | IDXA | 01 0C 01 00 | 268 | link to triangle strips: 00268-.IDXA |
| 0x20 | IDXA | 01 11 01 00 | 273 | link to face groupings: 00273-.IDXA |
| 0x24 | TXMP | 01 D8 00 00 | 216 | link to texture: 00216-.TXMP |
| 0x28 | res_id | 00 00 00 00 | unused | never used in Oni |
| 0x2C | unused[20] | AD DE | dead | blank filler |
- Vertices
- XYZ and UV coordinates are stored in parallel (same number of entries in PNTA and TXCA).
- Vertex normals
- The first VCRA stores the normals for every vertex (same entries as in PNTA and TXCA).
- Vertex normals are supposed to be used by Gouraud shading (directional lighting).
- The precomputed normals are apparently ignored by Oni, which generates its own...
- Face normals
- The second VCRA stores the normals for every face (groups defined by the second IDXA).
- Face normals may be used for env-mapping (but vertex normals could also work there).
- The precomputed face normals are apparently ignored by Oni too... didn't check much.
- Triangle strips
- The first IDXA lists the triangles as strips. The IDs are the ones in PNTA and IDXA.
- The start of a new strip is signaled by a high bit in the ID of its first vertex.
- Strips are more optimal for rendering, they are generated when authoring an M3GM.
- Face groupings
- The second IDXA groups the triangles into faces (oriented by the second VCRA).
- Even if the normals are computed at runtime, the group assignment might be used.
- (e.g., if a face normal is defined as the average of the normals of the triangles)
| ONI BINARY DATA |
|---|
| M3GA << Other file types >> Mtrl |
| M3GM : Geometry |
| Generic file |