I don’t actually know all of the best ways to make an apt.dat file. The format is new and we haven’t had a ton of time to performance test it. But here are some thoughts:

  • One thing I know is…it is best to describe the shape you are using with the fewest number of nodes possible. In other words, let bezier curves do their thing, don’t add a ton of vertices to them. And please don’t add vertices to try to make the curves smoother. The best thing is to leave the layout simple and let X-Plane render it. In the future we will allow the user to set the level of smoothness based on his or her hardware. Adding more nodes will hurt quality – we will be able to pick better nodes at runtime than you can in the apt.dat file.
  • Avoid overlapping large areas of pavement. Overlap is bad – it hurts framerate by requiring the graphics card to draw the same pixels over and over. As X-Plane supports more advanced shaders for nicer lighting, this cost will be a lot heavier on users.
  • Ignoring overlap, the question of whether to have several smaller chunks of pavement vs. one large one is a difficult question. I would suggest moderation – try not to make too many individual pavement elements, but don’t make the entire element one giant pavement either. You may have to experiment to find the best framerate.

About Ben Supnik

Ben is a software engineer who works on X-Plane; he spends most of his days drinking coffee and swearing at the computer -- sometimes at the same time.