It has been a little quite here lately, but that does not mean I am not doing anything. So time for a little update. Apart from the fact that I have been away for a few days for work (attended a workshop in Engeland), I have also been working on the apron markings for the Schiphol scenery. Let me start with a little introduction on what we want to achieve in that scenery.
We want realistic markings, so that means we need more than only a yellow center line. We also need the red clearance lines for example or the white tow lines. And as the cream on the pudding we would also like to put in the road markings on the airside of the airfield (these will probably be optional, to keep the users with a not so fast PC happy as well). As we want more than only some yellow markings, it is clear that the XML options to place markings are not sufficient for use. Although I hope that in the future these XML markings will become more flexible, so that they allow those red lines and other cool stuff as well.
Another things that I should probably mention, is that we have been lucky to receive some data about which markings are where. That means that we do not have to draw them all by hand, but that we can use this data and convert it to some scenery. In the past I have made a converter for this and it created Fs2000 style roads for the apron markings. I used these as they are the easiest way to place lines with a certain width in the scenery and assign your own custom texture to it. But they also have a few downsides (of course). For example they are not floating point, so to prevent gaps between them you should use a rather small scale of the reference point. And another negative point seems that they are a little heavy on the frames if you use a lot of them. And I can assure we use them a lot, as there are a couple of ten thousand line segments on the airfield.
So now I have been trying to upgrade the converter a little bit and produce these markings in another few. And until now that is working out quite nice. Instead of placing all the markings as narrow roads, I am now drawing them as polygons using the floating point commands (like the Fs2002 GMax gamepack output for ground polygons, but then created by my own tool). The main advantage of this is that it seems to be better for the performance and also it makes it slightly easier to connect all the lines nicely together without gaps. To generate these polygons from the line data I am using the OGR library I talked about before. With this library I am merging all line segments in a certain area together and I then give this total line a buffer (so a width around it). The advantage of this method is that as all lines are first put together, the connections between the different segments are almost perfect. And luckily the library does most of the hard work for me.
I will try to post a few comparison images in the coming days, when I continue to test my new tool.