Appears to use LZ10 just like Pyramids, but a bit more complicated ;)
0x0000 - "3DCT"
0x0004 - 2 bytes, length of the unpacked data
0x0006 - 2 bytes, length of the LZ10 packed data
0x0008 - 20 bytes, unknown, CRC/hash (?)
0x001C - 4 bytes, unknown, always zero (?)
0x0020 - LZ10 packed data with...