The BWM (Bandwidth model) format was created for my horror game for the PSX which I'm recording a video series about on YouTube. It's currently very memory inefficient and has only very basic features.

The file format can now store the following:

• Vertex coordinates
• UV coordinates
• Normal vectors

All of the data is indexed in order to save space by reusing vertex, uv and normal data.

The format is currently limited to only quads.

Unlike responsible file formats this one doesn't have a header. It stores data in the following way:

All values are 32bit integers each split into 4 bytes. (DWORD) Meaning the final size is always a multiple of 4 therefore the file is 4-byte aligned.

The data is stored in the file in the following order:

Size (in DWORDs)    Meaning

[1]                 Number of faces - f_count
[1]                 Number of vertices - v_count
[v_count*3]         Vertex coordinates (3 DWORDs each)
[1]                 Number of vertex indices - vi_count
[vi_count*4]        Vertex indices (4 DWORDs each - 4 vertices in a quad)
[1]                 UVs count - uv_count 
[uv_count*2]        UV coordinates (2 DWORDs each - U,V)    
[1]                 Number of uv indices - uvi_count
[uvi_count*4]       UV indices - (4 DWORDs each - 4 UVs in a quad)  
[1]                 Normals count - n_count 
[n_count*3]         Normal coordinates (3 DWORDs each)  
[1]                 Number of normal indices - ni_count
[ni_count*4]        Normal indices (4 DWORDs each - 4 normals in a quad)

• This format really needs a header. Especially considering the fact that there's going to be a future version which will break existing parsers.
• Store space by storing 2 16-bit numbers into a DWORD to save space.