If you Stitch two surfaces with the same surface normal, the stitched surface inherits this normal. However if you Stitch two surfaces with opposite surface normals Inventor seems to pick one at random, and it can swap*. This reverses Trim or Split commands further down the tree with annoying and time-consuming results. Please add an option to the Stitch command to allow the user to set the stitched surface normal.
If you work with surface normals please see my related idea to display surface normals without using the Construction environment
https://forums.autodesk.com/t5/inventor-ideas/check-surface-normal-without-using-construction/idi-p/...
*I create hull surfaces in a 3rd party application and import them into Inventor, then stitch them together. If I have to change the hull I do it in the other program, import it into Inventor again and then update the surfaces in the stitch. Even though they are surfaces from the same source file that have gone through the same process the updated stitch often has the opposite surface normal to the original.
