I have built a 3d cinema model by using 3ds Max (Autodesk product), then i saved the file as FBX file to be imported to FDS. I found that each 3d geometry was read as a split obstruction by FDS, then, i specified the reaction, i defined the materials, i attached the required surface for each obstruction, and finally the mesh was successfully generated and the file run without any errors. But, after the FDS run has finished (after 180 seconds) and the smoke view run also successfully, i found the temperatures at all the specified x-y planes are ambient temperatures. it seems like all obstructions were obstructions to the flow and they were not take part on the thermal and burning calculations. My question, are the obstructions treated as a 3d surfaces rather than a 3d solids? If yes, it might be converted to 3d solids or not? If no, how may i overcome this problem?