Easy to fix... Vertices/Split in UVMapper as mentioned. If you don't have UVMapper, you can spelit vertices with Poser.. #1 Select your imported cylinder. #2 Grouping Tool. - New Group.. "Ends" is a fine name. - Select the Top and Bottom of the cylinder. #3 Still Grouping Tool. - New Group.. "Base" is another good name. - Select the rest of the cylinder. #4 Grouping Tool stil. ;) - Spawn Props. #5 Export the Ends and Base as the new OBJ file. The exported version now has the vertices connecting the top and bottom to the rest of the cylinder split, so it will render without that rounding effect.