Is Prusa Slicer smart enough to not print in mid air?
I had a model once with a small cylindrical hole in the bottom that only extended a little way up the full model. The cylinder was small enough that bridging across the top would have worked fine, but cura produced gcode that tried to print a circular "roof" starting on the inside of the cylinder. Needless to say there was no adjacent plastic for it to stick to, so spaghetti just fell into the hole. Is Prusa Slicer smart enough to recognize it needs to order the print commands so there is adjacent plastic for the new print to stick to? I modified my model by giving the hole a cone shaped "roof" so it had to print that from the outside in as it worked up the layers, and that worked OK, but it seemed like a sufficiently smart slicer could figure out it was printing in mid air and manage to print a flat roof correctly.
RE: Is Prusa Slicer smart enough to not print in mid air?
No. What you are asking the slicer to do is to asses your model and make changes to the part when it slices. A slicers job is to reproduce the part as designed faithfully. As the designer you can make a decision about turning the bottom of the hole into a cone as you know the purpose of that hole and if it will stop the design from 'working'. A machine, even a clever one can not do that (yet). There are many possible techniques you can use, from using what you did or adding a sacrificial patch for example or using a succession of bridges at different angles for things like counterbores.
As a designer you should design your parts to take into account the limitations and advantages of the production method. This applies to all manufacture methods in industry and is what designers do. Well good ones anyway. Design for manufacture. Its the difference between making a part that is difficult to produce and has a low yield to one that is easy and has very little if any failures during manufacture. This applies to everything and not just 3d printers.
The slicer will however follow any slicing options you may have enabled, so if you select automatic support it will try and determine where needs support based on the parameters you have configured for that function. Usually a human is better at determining these things anyway which is why the tools are provide for you to mark and define areas that need support for example. Or where to place seams for best visual looks with the seam tool. Learn to effectively use what tools the slicer does give you, there are many.
RE: Is Prusa Slicer smart enough to not print in mid air?
I don't feel like I'd be asking it to change my model. I'd just like it to rearrange the order of print operation so it doesn't print plastic that isn't adjacent to some other plastic instead of being out in space not supported by anything :-). I should probably just download Prusa Slicer and preview the gcode to see if it has the same problem.
RE: Is Prusa Slicer smart enough to not print in mid air?
OK, I did download Prusa Slicer and whipped out a simple example in OpenSCAD, and it does print OK, simply printing a bridge back and forth across the top of the hole instead of trying to print circles across the top from the inside out like the version of cura I was using back when I tried this on a real model. So I guess my anwer is that it is smart enough :-).