I have read many threads here about importing and exporting stl files and scaling issues. None of them address what I am seeing.
I use 3D Studio Max and no matter what type of units I set it to when I import an OBJ it is always off scale. Clicking on the auto adjust scale option makes it worse. It seems to always assume everything I am importing is in inches no matter what and uses those inch measurements in millimeters.
To my knowledge OBJ format does retain scale. I don't know how Simplify3d reads this information.
These first tests were done with 1 cube where I kept changing the units of the scene and let the object stay the same size in relation to the unit type.
Export a 1 cm cube Imports as 1 mm cube
Export a 10 mm cube Imports as 1 mm cube
Export a .01 meter cube Imports as 1 mm cube (see a pattern here?)
Export a .394 inch cube Imports as 1 mm cube
Export a 1 generic unit cube Imports as 1 mm cube
Now I am messing with the scale of the object I export.
Export a 10 generic unit cube Imports as 10 mm cube
Export a 100 mm cube Imports as 10 mm cube
So it looks like it is just taking 3D Studio Max generic units and using those as mm no matter what. It isn't actually using the units the file is exported as. Is this behavior correct? It seems wrong. If I were to do this same experiment and import into Maya it will understand the unit differences. It will treat a obj exported at 10 mm and import it as 10 mm or 1 cm. What you would expect. Am I missing something? I looked all over for units setup or even an import export units settings. Nothing to be found. Any help would be great. I hate having to use generic units as mm to get Simplify3D to get the numbers right. It's wrong in all the other software packages I use.