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FSXA Autogen on transparent photoscenery?

Hope someone could give me a quick answer on this.

I know its only possible to place autogen on photoscenery.

But what if the photoscenery is edited totally transparent, so the default ground is seen underneath.

Would it still then be possible to place autogen and would it show correctly?



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FSDevConf team
Resource contributor

I know this idea has been tried. If I remember correctly completely transparent does not work, where the autogen buildings are it should not be transparent. But the rest can be transparent.


Resource contributor
Even "partially" transparent (non-white blend mask) will inhibit autogen.

Missing data has the same effect. Not possible to annotate transparent photoreal.
Ok, and I guess the result will be the same if the autogen is first placed on a non-transparent photoscenery, which after compilation are edited fully transparent?

As a side question, if the photoscenery covers a lake I would assume it would not be sufficient to make the photoscenery fully transparent for the lake underneath to show with 'FSX water'? I spite of transparency I would still have to create a water mask?



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FSDevConf team
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Using the blend mask for the lake would work, if the lake below it exactly matches the shape of the lake on the photo. But you will get nicer looking results in general by using the water mask. You can even make the lake from the photo only half transparent to still see some of the colours and details from the photo.
My problem is that in some remote areas of the world photoscenery are very bad and useless, but I need it if I want to 'plant' my own autogen.

So I am trying to use the photoscenery as a sort of canvas to paint on and nothing else.

This also goes for the present water in form of a lake or river bank. I really just want to 'cut' the scenery off somehow along a river or a lake, if transparency is not an option.

The areas are typically only minor airstrips with immediate surroundings.


Just to clarify what the goal is for the opening post: :confused:

Are you wanting to replace all existing autogen annotations of the underlying default scenery ...within areas covered by "transparent" custom photo-real land class texture tiles ?

Or are you wanting to add custom autogen annotations which replace only portions of existing autogen annotations of the underlying default scenery ...within areas covered by "transparent" custom photo-real land class texture tiles ?

If the latter scenario is your goal, IIUC, it may be possible to do this using a blend mask having the proper graphical attribute for transparency which prevents default autogen annotations from being displayed in specific areas of the "transparent" custom photo-real land class texture tiles.


But, AFAIK, this can only be done when both the aerial imagery and blend mask data is submitted at the same time with a multi-source INF file to be compiled into a BGL by FSX Resample.

And with FSX Resample being used, one could not later edit resulting texture tiles as they are packaged into an inaccessible output BGL containing imagery, blend, and placement info all in (1) file ...which is placed into a local paired \Scenery folder rather than a local paired \Texture folder.

The local paired \Texture folder would then contain the *an*.agn autogen annotation files.


PS: Some related info may be found in this and other linked threads:




FYI: I haven't had time to test this personally yet, but it may also be possible to "additively" annotate default scenery tiles by adding a small land class polygon (which IIUC is actually "invisible" or "transparent" between the border of a un-blended polygon and the border of a surrounding land class quad matrix cell / tile).

It is not yet known just how small such a land class polygon can be (or whether it needs to contain opaque / visible content) ...to still allow this to work as discussed here:



However, the FSX "Terrain and Scenery" SDK document (from SP1 / Acceleration SDK) in the section entitled "Performance Tips for Aerial Imagery" imputes another caveat regarding whether custom photo-real land class textures may be able to render at run time in FSX:

"Default land class textures will be used if the terrain system cannot find photo-imagery at LOD13 (5 meters per pixel) or greater detail.

This can lead to default textures appearing when photo-imagery is desired.

To ensure that the LOD13 requirement is met, consider using LOD=Auto,13 in the [Destination] section of the .inf file.

[FSX SDK install path]\SDK\Environment Kit\Terrain SDK\Terrain and Scenery.html


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Yep the 'portions' option. Within the area of the airstrip and immediate surroundings i want to replace all autogen, since it is not correct.

But my photoscenery covers a somewhat larger area, so I want to get rid of the 'excess' photoscenery.

It could be done then by blending the 'excess' portions of my photoscenery if I understand this right. But I will still have to leave my annotated area non-transparent and maybe add some appropriate color to it.

Sometimes I wish I could rotate the map in SBuilderX before extracting and compiling an area. This way I could avoid river areas, which means adding water masks as well.

Thanks for the links.
The polygon/autogen approach sounds worth testing.

Hope that works out OK for you ! :)

Please post back with some details as to what worked, and how you achieved your goal, since this seems to be a relatively unexplored area of FS scenery building ! :idea:

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I had some doubts about adding autogen over transparant textures (partially tranparant in my case) with the annotator until i found this thread!

I am not sure i understood all you said because english is not my native language. So i will post a picture and a simple question.

Please, give me a clear answer...

This is my photoscenery with semi-transparant areas (not completely black in the Blend mask) where we can see the default ground texture (rain forest).
Will I be able to place custom autogen trees over those areas with the annotator ?
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I have been insanely busy at work, so this 'project' has been on stand-by and still is sort of.

BUT I have done some preliminary tests and in these tests this method seems to work :)

What I did was extract a very small photo via SBX and compile it.
The photo of this remote area is ugly, useless and of no use as a photoscenery.
Then I added some autogen trees both over some the area I wanted to 'build' and some of the area outside.
Then I created a blendmask. This was done with 80-85% black over the area I want to 'build up' and 100% over the rest.
The watermask was just a copy of the photo. Actually I should perhaps have left this mask just blank.

All of the area now showed default autogen except my 'build area' which showed my autogen placed trees.
The photoscenery was invisible, well almost. There was some small white streaks which in some places was showing. This might have to do with how the watermask was created or another option could be to simply color it out.

During my preliminary tests I found a limitation using other than 80-85% black color for the blend mask, but this has to be verified by further tests.

I actually had a set of pictures but after a FSX reinstall, I cant find them.
I still have the scenery variations though so I can probably recreate this.

Hi Michael:

Many thanks for sharing your initial report with us; I look forward to seeing more of your results when you get some time to post it here. :)

Ok, I recreated the scenery and took a screenshot.

In this picture FTX is activated and this was not the case in my first pictures.

The original photoscenery filled all of this area and also covered the river.

The red area is my 'build up' area which is defined by the 80-85% blendmask and you can see the airstrip as well.
Outside the red area a 100% black was used in the blendmask.
The blue area is where I placed the autogen trees on the original photo.

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Staff member
Resource contributor
Hi all.

I played with this some time ago. I have an example of a small rectangular area that has a totally transparent ( 100% ) blendmask, and autogen applied. FLT file is included, so you can find it in FSX. The image is simply a medium gray value ( 127 ) bmp.

In the above example, I don't think there is anything magical about 80-85%. 99% would work as well, I believe. Don't use compression in the INF file.


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Hi Dick:

Many thanks for offering access to that "TransAuto.zip" file set.

Possibly this is a temporary thing, but I presently cannot download via the posted link, and I also cannot ping http://www.filesplat.com, https://www.filesplat.com, or www.filesplat.com. :eek:

I'm hoping perhaps alternatively another "Cloud" location might be an available option you could post the file at, so that those of us wishing to download "TransAuto.zip" could see what IIUC is ...your worked example of autogen displayed on transparent / "invisible" custom photo-real land class ?


Update: After midnight this evening I was able to download the TransAuto.ZIP file from:


BTW: I just found this older and very interesting thread on this same subject:


Unfortunately, the linked "Transparent_Photoreal.zip" file in that thread throws a "Server Error in '/' Application" error at: :alert:

http://www.timacheson.com/SkyDrive/DirectLinkRedirect?pageUrl=http://cid-f3950c5bbd2bcfa1.office.live.com/self.aspx/FS Addons/FSX files/Transparent^_Photoreal.zip


- See the post below for a working link to Dick's "worked example":


PS: I was wondering if you have also tested whether a version-specific comparable technique of transparent / "invisible" custom photo-real land class would work to allow display of autogen annotation on such texture tiles in FS2004 ? :confused:

Thanks again for any further clarification you could share with us on the requirements for / feasibility of ...making this methodology work in FS Development. :)

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Staff member
Resource contributor
I believe for FSX you can either make an entire rectangular area transparent, and use autogen, or you could define an irregular poly in a rectangular area, as noted above... I would use 0,0,0 ( black ) for the unused area and 1,1,1 ( 99% black ) for the transparent autogen area in the blendmask.

In FS9, you can use a vtp2 poly. In vtp2, I believe you'd need a single pixel in the tile as non-transparent, if memory serves me right. The mask is the alpha channel... normally used for water, but vtp2 shows it as transparent.

Hi Dick:

Thanks for sharing those additional insights; I'm confident that a number of us will be exploring this as an option for specialized objectives in our FS scenery projects in the future ! ;)

Some questions in regard to the legacy VTP2 poly methods to achieve the same result of a "transparent" rectangular area or irregular polygon inside an area:

* Can the "blank imagery" grayscale bitmap (with the single non-transparent pixel) be utilized with a separate "Blend Mask" ex: TIF file instead of the alpha channel in the "blank imagery" bitmap file ?

* Do the same minimum LOD-8 tile size requirements apply as described in relation to the SBuilder for FS9 VTP photo scenery methods ?

* Can a FS terrain mesh with a resolution higher than LOD-8 (ex: LOD-11) be used to make 'non-flat' VTP photo scenery via SBuilder for FS9 methods ?

Thanks again for any further insights you might be able to share with us on these techniques. :)

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