Allow gap fill only for top layer

[jrw]

The feature Allow gap fill when necessary is useful for covering up gaps between perimeters on thin walls when the Infill outline overlap doesn't work. The attached image shows an example of the problem with the Benchy with 0.12 mm layer height. The issue occurs when choosing 3 perimeter shells instead of 2. The problem with Allow gap fill when necessary is that it is applied to every single layer which causes an unappealing outer surface and lots of stringing. For prints that require an aesthetically pleasing surface rather than ultimate strength, only the gaps on the top visible surface need to be covered.

Therefore, I suggest that the developers of S3D add a checkbox beneath the Allowed perimeter overlap which says: Top layers only. When the user checks this checkbox, the Allow gap fill when necessary will only be applied to the top visible layers. This will create an aesthetically pleasing print where the visible gaps are filled without wasting time and material by filling the gaps on the layers below, and with good quality surface and no extra stringing.