Your GEOM parser may be inaccurate.

[anonhostpi]

This may not be accurate

• Sims4Tools/s4pi Wrappers/MeshChunks/GEOM.cs

  Lines 154 to 171 in fff1936

  	int numFacePointSizes = r.ReadInt32();
  	if (checking) if (numFacePointSizes != 1)
  	throw new InvalidDataException(String.Format("Expected number of face point sizes to be 1, read {0}, at 0x{1:X8}", numFacePointSizes, s.Position));
  	byte facePointSize = r.ReadByte();
  	if (checking) if (facePointSize != 2)
  	throw new InvalidDataException(String.Format("Expected face point size to be 2, read {0}, at 0x{1:X8}", facePointSize, s.Position));
  	faces = new FaceList(handler, s);
  	if (version == 0x00000005)
  	{
  	skinIndex = r.ReadInt32();
  	}
  	else if (version == 0x0000000C)
  	{
  	unknownThings = new UnknownThingList(handler, s);
  	unknownThings2 = new UnknownThing2List(handler, s);
  	}

See the contents of "> Modified GEOM ksy"

• Just Citing/Acknowledging Your Work kitlith/sims3-rs#3 (comment)
  • most of this thread talks about the TS3/TS4 GEOM struct

[kitlith]

instead of throwing the kaitai struct definition at them, since they're not using it and may not be familiar with it, how about this description of the change I'd make to the wiki? (the following is quoted from earlier in that discussion)

From the wiki: http://simswiki.info/wiki.php?title=Sims_3:0x015A1849

DWORD ItemCount                 // will usually be 1 (hardcoded in pipeline exporter), but sometimes other numbers
--repetition ItemCount:
	BYTE BytesPerFacePoint

DWORD NumFacePoints
--repetition NumFacePoints:
	BYTE[BytesPerFacePoint]	// Given that ItemCount is 1, BytesPerFacePoint is 2, this is a list of WORDs
				// Each set of three forms a face.

according to my pattern file and binrw parser, that last section should be indented, part of the previous repetition group.

like so:

DWORD ItemCount                 // will usually be 1 (hardcoded in pipeline exporter), but sometimes other numbers
--repetition ItemCount:
	BYTE BytesPerFacePoint

        DWORD NumFacePoints
        --repetition NumFacePoints:
	        BYTE[BytesPerFacePoint]	// Given that ItemCount is 1, BytesPerFacePoint is 2, this is a list of WORDs
		        		// Each set of three forms a face.

naming on the wiki is a little weird, I'm pretty sure this is just a list of index buffers used for 3d rendering.

I have a piece of sims 3 custom content that the was motivation for that change, I still need to go check if I can share/link it.