adds an "connected surface mode" to the MLS visualization

[planthaber]

The lowest mls entries are drawn as mesh instead of individual quard, if activated (not default).
This eliminates visible gaps the the map representation (visible on the hills in the following pictures).

This approach does only changes the lowest surface, e.g. the first floor is drawn as before.
It is also expected that the MLS entires are ordered by position (lowest first).

Nevertheless, this can improve the visual quality of Screenshots or videos.

If the cycle color mode is switched off, "estimate normals" should be active:

[saarnold]

This looks quite nice 👍
Will it also become part of the new MLSMap visualization?

[planthaber]

I guess yes. In the end it isn't much complicated, I can add it to the new MLSMap once Christoph has finished refactoring

[chhtz]

No objections against that. I guess the only complicated thing is implementing this to true multi-surface maps (with more than one surface). I also did not port "estimate normals" so far (also mostly because for sloped surfaces it is not necessary). OTOH, finding connected patches in MLS maps will be essential for navigation, later.

Refactoring is essentially done btw, you can add stuff, if you like.

[planthaber]

"estimate normals", for the surface can also be done by an osg::SmoothVisitor, we only need to place the surface into a separate geode, so "estimate normals" is is a one liner. The smoothed vertical blocks are looking quite ugly when the visitor is applied