a.zuzek wrote:I want to create scenery that can be used in the base package. I have TerraGear CS and QGIS with the GRASS plugin installed in my system and I am able to edit shapefiles. Based on the wiki documentation at
http://wiki.flightgear.org/index.php/Using_the_Custom_Scenery_TerraGear_Toolset I was able to improve the scenery around the SABE airport, but apparently I did not do it in a way that can be easily added to the base scenery package.
What I did was download the shapefiles of the area of my concern, added each one as a separate layer in QGIS and also added a Landsat image as the background layer to use as reference. I would then edit the shapefiles by moving vertexes, adding new ones, adding 'islands' to existing features or adding rings to existing features. In the parts of the scenery that I edit, I try to remove any overlaping of landclass, but the truth is, there is a lot of overlapping in the existing vmap0 data. My idea was to work incrementally, that is, do some editing, send the shapefiles and then repeat the cycle over and over again till I all the area is fixed. That way, at any point, the shapefiles wouldn't be worse than what I got at the beginning, since, as I understand, the current base scenery package was generated with the unmodified vmap0 data which has a lot of overlapping already.
From what I read in other posts in this forum and some comments on private e-mail, it seems to me that I should not edit existing shapefiles, but that I should creat new ones for the area I am interested in, being careful not to create any overlapping but also making sure that all terrain is covered by one landclass. Is that correct? And if so, what is the reason for doing it that way? Is it related to how the modified scenery is integrated into the existing one? I also read somewhere (I think it was on the custom scenery project site) that editing of shapefiles of all landclasses should be done in one single layer. Is this the way you are doing your editing? If so, why?
Cheers,
Alejandro
Hola Alejandro,
I'm not sure what you did exactly to create Buenos Aires - it certainly looks good from your screenshots =) - but I'm hoping you'll send me your shapefiles. I may be able to make it easier for you and get your files into the game.
How were you able to use the LANDSAT image, did you convert it into latitude and longitude?
There are several reasons for creating one single shapefile when digitizing when you're creating it yourself (as opposed to editing a bunch of shapefiles). The two main ones are listed below.
1) Topology (
topologia, parece). One shapefile means there are no gaps or overlapping between the shapefiles. This is very important, considering you can't have more than one layer at one point in time in FlightGear!
2) Merging. It's much easier to merge the files into the scenery when you have one big shapefile.
The large shapefile isn't just one landclass, either - you have to designate what landclass goes where.
Here is an example as to how I go about merging the scenery to be included in the database. The following is a picture of Madrid, Spain, an area of scenery I am proud to have finished though I don't think it's been distributed yet in the official database.
spain_coverage_2.jpg.jpg
How to read the map: The gray area is the original vmap0 files - the white area is where there is no vmap0 coverage (other than the shapfile saying it is land). The green areas are the areas I created. To give you a sense of the size of this project, the square is 2x2 degrees!
In order to create this map, I merged all the vmap0 layers together into one single shapefile (preserving their landclass). I also had one custom shapefile. The different polygons represented different landclasses - city, grass, etc. I then "cut" a hole in the vmap0 layer and then added my own scenery into the "hole". This made sure that each point on the map corresponded to only one scenery/land cover type.
If I had a bunch of different shapefiles, some of which overlapped, I would have had to merge them all together in order to achieve the same result.
If any of this doesn't make sense, please feel free to ask! I'll try to explain more clearly =)
Thanks for your interest in flightgear, and please check your private messages (and send me your shapefiles),
Cheers
John