OK, Eu uso esse codigo para a modelagem.
txd = engineLoadTXD("12andar.txd", 1933 )
engineImportTXD(txd, 1933)
dff = engineLoadDFF("andar.dff", 1933 )
engineReplaceModel(dff, 1933)
col = engineLoadCOL ( "12andar.col" )
engineReplaceCOL ( col, 1933 )
engineSetModelLODDistance(1933, 500)