The model tag (mode) explained. SOMEWHAT LONG
                                                 POST 

Posted by Loshadh on Sunday, 28 June 1998, at 9:17 p.m. 

The 'mode' tag. 

The mode tag handles a portion of the models you see in Myth. The 
other portions are taken up by the geometry tag (geom) and the texture 
applied to the model. The model tag data structure is as follows (all 
offsets are from the end of the header unless otherwise specified). 
Once again, everything is in a structure format. Data of type "long" 
is 4 bytes, data of type "short" is 2 bytes: 

--mode tag header: 

typedef long geomTAG; 
struct modeHeader 
{ 

long unk01; // No idea. 

geomTAG geomTagID; // The four letter geom tag to use 

short unk02; // No idea. 

short vertexFlagCount; // Number of vertices in the model 

short unknownCount; // No idea. 

short meshMarkerCount; // Number of "mesh markers" 

long vertexFlagOffset; // Offset to the flags section 

long vertexFlagLength; // Length of the flags section 

long unk03; // No idea. 

long unknownOffset; // Offset to ? section 

long unknwonLength; // Length of the ? section 

long unk04; // No idea. 

long meshMarkerOffset; // Offset to the mesh marker section 

long meshMarkerLength; // Length of the mesh marker section 

long unk05; // No idea. 

long dataStart; // Offset from beginning of header 

// to the start of the tag data. 

long dataLength; // Length of the tag data. 

long unk06; // No idea. 
}; // 64 bytes 

--mode tag flags: 

struct modeFlags 
{ 

long vertexFlagData // Number of flags equal to 

// the number of vertices 

// for the model. 
}; // 4 bytes per flag 

So far, I've seen values of 00 00 00 00 and 00 00 00 01 for the 
flags. A total of [vertexFlagCount] flags are present. 

--mode tag unknown section 

struct modeUnknown 
{ 

long unknownData[16]; // No idea. 
}; // 64 bytes per entry 

I have absolutely no idea what this section does. 

--mode tag mesh markers 

struct modeMeshMarkers 
{ 

short meshMarkerX; // X position of marker 

short meshMarkerY; // Y position of marker 

short meshMarkerFlags; // Flags for meshMarker point 

short unk01; // No idea. 
}; // 8 bytes per marker 

It seems that these markers denote how the mesh around the model 
is to behave. It seems that those markers with a flags value of 
00 07 are contained within the model (or along its edges), and 
those with a value of 00 08 are one mesh unit outside of the 
model's perimeter. There may be other values for these markers. 

Well, that takes care of the model tag as best as I can figure it 
for now. Next comes the geometry tag. 

Loshadh