• Which the release of FS2020 we see an explosition of activity on the forun and of course we are very happy to see this. But having all questions about FS2020 in one forum becomes a bit messy. So therefore we would like to ask you all to use the following guidelines when posting your questions:

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FSX Installation with the custom terrain.cfg

I could only find one thread asking this question (but not the answer I was looking for), so let me ask - during installation of SBuilderX you are asked if you want the custom terrain.cfg file installed. A few questions:

1) What is the purpose of this custom cfg. file? Does it repair some issue with FSX that was discovered?

2) Does SBuilderX need it to be custom in order to run properly?

3) What exactly is it changing?

4) Can I make this change later by just re-installing SBuilderX?

I decided to opt out of changing my cfg until I know more about what is happening. Can anyone shed some light on this?




Staff member
Resource contributor
I don't recall if the altered terrain.cfg is added by SBuilderX, or if you must install it, then use it in SBuilderX.

You can certainly reinstall SBuilderX with the option later.

You could download the altered terrain.cfg file here:


This fix has been around since November 2006. It fixes some issues and adds enhancements to the display of vectors ( lines and polys ). The most notable fix is that the default water in FSX can show rocky outcroppings randomly. The Thames river is very noticeable. The altered terrain,cfg gets rid of the rocks.

From the altered version:
//This modified FS X terrain.cfg is the result of discussions among
// various scenery designers during testing of Flight Simulator X.
// The modifications are the work of
// Richard Ludowise and Luis Féliz-Tirado.
// November 2006
// Modifications include the following:
// - 3 new land class values added:
// 	252-custom seasonal, 
//	253-custom non-seasonal, 
//	254-transparent
// - VTPLayerRenderPriorities
//	changed	7=30000
//	to	7=20000
// - all FS9 legacy shorelines 2-109 now have a GUID
// 	and a StripWidthMeters added,
//	 making them usable with Shp2Vec
// - wave effect removed from
//	 dry water body shorelines 10,28,37,64,100
// - wave effect added to
//	 lake urban perennial shoreline 41
// - legacy airport backgrounds (obsolete)  167-185
//	changed 	FlattenMode=flat
//		FlattenPriority=50000
//	to	FlattenMode=none
// - land class polygon white coral beach 192 now references
//	 coral texture, value 132
//	 instead of tansand, value 137
// - all default fs x hydro polygons 194-199 now reference
//	 non-rocky water, ocean_sea_large_lake_0
//	 instead of ocean_sea_large_lake, value 100
// - legacy water flatten and mesh-clinging water polygons 380-381
//	 now reference non-rocky water, ocean_sea_large_lake_0
//	 instead of ocean_sea_large_lake, value 100
// - added FS9-style land class polygons 383-385
//	 referencing
//	 252-custom seasonal,
//	 253-custom non-seasonal,
//	 254-tranparent
// - added hydro polygon rockslope 386 that references
//	 rocky water, ocean_sea_large_lake, value 100
// - added wave effect without a shoreline texture, 387
// - added utility without grass corridor, 388

The file can be opened with notepad, and it is pretty self-explanatory. It is not required for use with SBuilderX or FSX... but if you design scenery using it, you should distribute the terrain.cfg with your scenery. It's pretty safe to use... I don't think Luis or I have received even a dozen complaints about it in all these years.

There are other versions of terrain.cfg about in the community. I do not know if they are compatible with this version, but this version is certainly the most used by the freewae community... in fact, I don't believe the others are freely available at all. Some of these other software packages have installers that accommodate other versions of terrain.cfg

The only bad thing about using an altered terrain.cfg is that you can only have one version at a time! It would have been nice if each scenery folder could have it's own terrain.cfg, but that was not to be, as no one at the Aces team took the problem seriously... why have a whole section of the SDK devoted to the terrain.cfg file, and then limit it to one instance in the sim?

Bottom line:

If you are happy with the default settings of the terrain.cfg, and how it looks in the sim for you, leave it alone and use SBuilderX with the default. If you like the changes in the altered version, then use that, and include a copy in your scenery distribution, with a note for endusers to replace the original ( and save the original with a different name! ).
I think if you tell SBX to use the modified terrain.cfg, it will provide options for the additional terrain vector types when you set properties for your vectors. SBX uses some files lines.txt, polys.txt, and lands.txt to capture the terrain.cfg data. I think it also saves the thumbnails based on this.

scott s.
Is still necessary to install custom terrain.cfg even with FSX Steam Edition. I answered no for the moment. Is better to reinstall with its custom?