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Guest jimkeir

How to remove the default airfield boundaries

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Hi all. I have just done a quick search of this forum and can't find any information.Does anyone know how to identify which ABxxxxxx.bgl file contains a specific airfield boundary? I can't see how to relate the number to a location on the earth's surface. I am looking to remove the default airfield boundary for NZPP.Thanks everyoneJames

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Hello,The following (taken from the SBuilder Help file) is also valid for ABxxxxx files:Inside these folders you have several files. The following files are LWM files:FL9XXYY0.BGL - these files refer to flatten polygons HP9XXYY0.BGL - these files refer to hydro polygons (and/or hydro area fills) All LWM files cover a complete LOD5 square. The XX and YY appearing in the filename refer to the X and Y coordinates of the LOD5 square to which the file refers to. In order to know which file applies for a given location you look to the LOD5 coordinates that appear in the status bar when you have the mouse in the desired position. In the south of Portugal, for example, the status bar shows LOD5 45 18. Therefore if you want to load the hydro LWM data for that region you look for the file HP945180.BGL. Note that there is a leading 9 and a trailing 0 in the sequence of digits that define the location.Regards, Luis

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Hi LuisThanks for the response. That makes a lot of sense.Now, I think my next question is, given that I don`t have sbuilder, how can I determine the LOD5 grid reference for my location? I`ll check out sbuilder but if anyone knows a way of determining the lod5 square for a given Lat / Long that would help me a lot. Thanks again Luis.James

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I believe in the SDK it says that an LOD5 covers 3.75 degrees Longitude and 2.8125 degrees latitude.0 starts at 180 degrees long and 0 degrees N. lat. That should give you 96 LOD cells E&W and 64 LOD cells N&S. Hope that's clear.

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Hello James,Try 994460 - all related files contain those references, but as you say, you want the airport background, AB994460.You can easily get this kind of information using SBuilder or Jim Keir's LWMViewer.Best regards.Luis

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Hi I downloaded the free version of sbuilder and created a generic project centred on the Lat & long of the airfield I was after and sure enough, 994460 is spot on. Thanks everyone for the help. Its sooo good to have removed the massive default airport boundary sheet. On a separate note, thanks Luis for the tip re lwmviewer. What i really want to do is just remove NZPP's boundary file, rather than the whole lod5 square. LWMviewer may we be just the tool I need. CheersJames

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Maybe I am going about this all wrong but I always try and avoid tampering with any of Microsofts default AB, AP, HL, FL, etc. type bgl's. I do decompile and read the data for knowledge but never change anything in those root default files.I am aware that some mesh issues require that the FL's must be changed to get the correct results and it has been explained that the stock file becomes a backup so the newer bgl can be used.I replace the airport boundry using Sbuilder and draw a VPT2 poly precisely around the boundry. I then choose from the classes a ground texture to replace the entire airport boundry with what I want and it blends to the ajacent ground texture scenery very well. If we follow the guidelines that are explained in the SDK's and place these new bgl files in the expected appropriate folder then FS9 handles the priorities on its own very well. Maybe you guys are talking about something totally different and if this is not the accepted way I am always willing to learn new techniques from those that have tested their results.

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No, Jim, you are absolutely right. There is no need to modify any of the default files, with only one exception. As for James, he can simply exclude the default skirting and draw a new one, as you do.The only exception is the default hyp (Hydrographic Polygon - HP) files. A characteristic of default water is that its altitude is set to 0 meters, and there is no way to exclude or override this altitude when drawing new water masks (coasts). So, your new coasts will be flat if they extend beyond the default. The only solution is to go in the default, modify that, and distribute it (although you could "just say no" and wait for the next version of FS, but who does that?)While I understand and share your reticence to distribute modified default files, I do not see any problem in the modification itself. I have modified multiple default files for my own use. And there are no unpleasant consequences, the game looks better, and anyway the changes that I make are wholly consistent with the default code and do not crash FS or make it unstable.It is all just code, and pretty simple code at that, so if someone wants to go in and "decompile" and change it, well, they can just read the SDKs that show exactly how to do so.Perhaps you could try it and slowly you might start to change your mind. Or not.Best regards.Luis

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Thank You LuisI just wanted to make sure I am staying in the mainstream of what works best based on those like yourself who have a good working knowledge for these areas of design.

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Hi,LWMViewer won't let you edit the existing polygon features directly. It will show you what they are, give you lots of information about them including the files they come from, and allow you to preview changes without having to reload FS.You can export LWM source code by right-clicking on the particular file and selecting 'Save Source'. The code it writes is commented and I'm sure you won't have any problem reading it. The easiest way to find a particular feature is to serach by height (in meters) and then check the coordinates in the accompanying comment. It also gives other related coordinates, all of which are listed in the 'Info' panel in LV2.There are other threads here about how to edit these files so I won't go into details. Luis is right though - it's far better to override the default files if at all possible than to modify them.Cheers,Jim

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