I apologize in advance considering I'm in a very complaining mood at the moment.
I've just compiled 4 square degrees of scenery around the Minneapolis/St. Paul area in an attempt to figure out whether or not my Alaska scenery creation process worked on places in the lower 48 states.
Fortunately, the answer is yes, the process works and the scenery built successfully. Minneapolis is kind of boring minus the lakes, but the scenery also looks like the upper midwest, and there are a lot of interesting rivers to follow.
Unfortunately, I've run into problems with what I'll call the "swirlies" and the "staircases".
The first is the "swirlies" - I'm sure people have seen these before, where someone builds a dense road network and all of a sudden all the textures are stretched into oblivion.
I'll call them the "swirlies" because up close the texture pattern looks like a swirl.
The second is the "staircases". Basically, the fan constructions don't include any sort of centroids, so for large glaciers the elevation literally goes up in steps as the fans "walk" up.
This "staircases" effect also causes an issue in mountainous valleys. Sometimes the fan will not pick up part of the canyon floor, instead going from peak to peak. This can have a very pronounced effect when you are flying, and there are instances of this in the Alaska scenery as well (and others, but this is the cause).
My question is, what can I do from a data point of view to fix these problems?
I'm using v.generalize instead of v.clean in my GRASS workflow this time around, which is much faster and gives better results - but it doesn't clean any vertices.
As a result, for both Alaska and Minneapolis sceneries, there are a number of strange constructions with the irregular mesh.
I know how the irregular mesh is formed. I've designed a couple golf courses for Links 2003 using a similar method and dropping a centroid or a few really can help the wireframe - unfortunately I don't have access to the actual wireframe scenery structure, nor is this a recommended way to edit the files.
I could also use v.clean and remove some of the vertices, which in turn would reduce the number of fans. I know there is a limit on fans or vertices? with .btg files, but this scenery is only of a "medium-high" quality, and compared to other sceneries I've created I'm not sure there's really a need to do this other than for performance. Plus, I'm loathe to run v.clean because pruning became very, very slow sometime in between GRASS 5 and GRASS 6.4, even though v.generalize doesn't remove any vertices, which is a problem.
Oh, and Minneapolis/St. Paul scenery is available for anyone who wants it, but please email me personally because it's buggy. (However there is one very nice grass-runway airport which is placed on the cliff of a river - technically a bug but taking off is a fun challenge!)
PS - I only get around 3-6 FPS on this brand new laptop(!), and I'm finding with 2.4 simply launching "fgfs --airport=KMSP --aircraft=ufo" loads up local weather/real-time weather, which is terrible for a simple scenery flyover test on a poorly performing computer - I get <1 FPS because I can't change visibility - is there a way to disable this feature from loading on startup from the command line?