FSXA Minimum size of photoreal image for use in FSX?

After some fits and starts, and a couple year vaction from attempting FS9 scenery, I'm getting back into a project to create FS scenery. I'm interested in moving up to FSX, to avoid the 4.75 m/pix resolution restraint in the old FS9 resampler.exe program.

Before I spend considerable money on some commercial aerial imagery, I would like to know if an aerial image have to be of a minimum dimension to be used with the FSX resampler? I am currently working on obtaining an aerial image of an airport I'd like to model, and was wondering if the image could be just the airport and nearby areas, or does it have to completely fill a LOD tile? (I seem to recall in FS9 an image had to completely fill a tile).

I'm completely new to FSX (I haven't even bought it yet - that will be dependent on being able to acquire the aerial imagery I need), so please be gentle. In addition, is there a specifice georeferenced file type (GeoTiff, etc.) that I should specify for my imagery in from the vendor? I know it needs to be in WGS84 projection. Any thoughts on this would be greatly appreciated!

Thank you.

Mark
 
Hi Mark:

Welcome back to scenery development for the virtual world of MSFS ! :cool:


It may be helpful to consider a review of the reference documentation for a popular and very capable FSX scenery creation utility "SBuilderX": :idea:

http://www.fsdeveloper.com/forum/showthread.php?t=5596


After SBuilderX is installed, you can review the Help file topic on Land Class scenery:

SBuilderX Menu > Help > Search Tab > Search String: "class" > click 'List Topics' > Land Classification > Further Reading



..And then the Help file topic on FSX custom Photo-real Land Class scenery

SBuilderX Menu > Help > Search Tab > Search String: "photo" > click 'List Topics' > Custom Ground Textures > Using a Map to create custom ground


NOTE: Both types of ground or terrain textures are forms of Land Class Textures which will automatically cling to the underlying terrain mesh, and which have practical limits of resolution due to the time required for the terrain rendering engine in FS to assemble the terrain mesh vertices and drape the textures on top ...while an aircraft is flying over it.


What is that practical limit ?

IMHO: terrain mesh @ 2.4 Meters between elevation data points (aka terrain vertices), and mesh-clinging terrain textures @ LOD 17 / QMID 19 / 30 cm. per pixel ...on the ground.

Beyond that, it is (IMHO) better for FSX performance, and for the likelihood of anyone with even the most powerful highly tweaked FS computer to ever be able to resolve one's scenery at run time during a flight ...to use 3D scenery objects mapped with higher resolution textures for the ground when building ex: a highly detailed airport. ;)

An example of this approach is OrbX's FTX Stewart BC scenery package (which actually uses 2 cm. per pixel for terrain textures on the 3D ground "model" !):

http://fullterrain.com/product_czst.html



Yet another type of scenery which is often used, particularly at airports where the terrain has purposely been flattened (to allow AI traffic and ground vehicles to work properly), is a custom textured "Ground Polygon".

The latter type of object is a 3D object of minimal thickness which has various layers of textures mapped onto it, and which is then placed on top of the flattened terrain on the ground underneath it.

This type of object can have even higher resolution textures which will render more quickly in the time required for the terrain rendering engine in FS to assemble the flattened terrain mesh vertices and drape the flat, textured ground polygon on top ...while an aircraft is flying over it.



However, in FS there is also a "visual display radius" limit as to how far away one's aircraft can be from an object and still see the textures at higher resolutions.

The farther away we move from an object, we will usually see the object shape displayed at a lower resolution, as most objects have lower 'Level Of Detail' (aka "LOD") versions of the object inside the 3D model which automatically shift into view.

And the farther away we move from an object, we will also usually see the object textures displayed at a lower resolution, as most objects have lower "MIP Map" versions of the texture inside the bitmap files which automatically shift into view when mapped onto the object.

Additionally, the farther away we move from the ground, terrain mesh also has lower "LOD" resolution versions of the ground shape which will appear along with lower resolution versions of mesh-clinging terrain textures mapped onto the ground surface.

This same behavior is seen with (IMHO) "properly" constructed flat custom ground polygons with textures which may contain MIPs.

Hope this helps you grasp some of the basics of scenery building. :)



PS: Making / modifying FS scenery can be enjoyable (and alarmingly captivating), but requires patience, a commitment to researching needed information from multiple locations at FS web sites all over the internet by using Search engines, a humble openness when communicating with others in forums, and a willingness to "RTFM".

Scenery building also requires one to "pace" oneself to prevent drawing premature conclusions about what can and cannot be done in scenery development for a given version of FS, and to take regular breaks from development / obsession ...to prevent "burnout".

And it is also perhaps even more important to prevent insidious neglect of ones involvement in the "Real World" ...and one's relationship with all the people in one's 'Real Life'. :rolleyes:

For some, it is easier to purchase several add-ons for FS which correct and enhance the terrain mesh, terrain textures, water bodies / shorelines, autogen objects, roads, AI traffic etc. and simply take an enjoyable flight in FS when one gets a few minutes free from "Real Life" now and then.

Others, such as we see here at FS Developer, may prefer to delve into the learning and scenery creation process in greater depth... for better or worse ! :p


GaryGB
 
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hcornea

Resource contributor
I have attention deficit, so in addition to Gary's detailed answer.

  • You will have no issues with what you are doing in terms of area.
  • The image can be (pretty much) whatever shape / size you want, and modern sat/aerial imagery at 30cm makes pretty nice scenery.
  • Doesn't have to fill / fit in with LOD tiles (You can almost ignore them for resampled photoreal)

Imagery needs to be in WGS84 datum. It can be in any form, but will probably come in GeoTiff or tif/jpg files with appropriate Ortho information (jpw or tfw) files.

If it comes in a different datum, it can be re-projected ... but Geodetic WGS84 is what you would like if you get a choice.

Jump in and grab a copy of FSX (should be able to get it for under $30 now) Make sure you get the Gold (or Deluxe, but preferably Gold) edition that contains the SDK, and patch the SDK to SP2 as one of the first things you do.
 
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I have attention deficit
I am a bit long-winded some (most) of the time... hopefully it helps folks with some inquiries ! :eek: :p

...so in addition to Gary's detailed answer.

  • You will have no issues with what you are doing in terms of area.
  • The image can be (pretty much) whatever shape / size you want, and modern sat/aerial imagery at 30cm makes pretty nice scenery.
  • Doesn't have to fill / fit in with LOD tiles (You can almost ignore them for resampled photoreal)

Imagery needs to be in WGS84 datum. It can be in any form, but will probably come in GeoTiff or tif/jpg files with appropriate Ortho information (jpw or tfw) files.

If it comes in a different datum, it can be re-projected ... but Geodetic WGS84 is what you would like if you get a choice.
Indeed, the new option of using GeoTIFF files for FSX custom photo-real land class textures makes life a lot easier, as FSX SDK Resample now 'auto-magically' makes the best use of what ever imagery tile 'sizes' we submit to it in a Geographic Lat / Lon Projection / WGS84 Datum ...Geo-TIFF file format. :)

< Sayyyy... that was a remarkably short and simple answer; maybe I could even get to 'like' this type of brief reply ! :D >

GaryGB
 
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< Sayyyy... that was a remarkably short and simple answer; maybe I could even get to 'like' this type of brief reply ! :D >

GaryGB
+1 :D :cool:
Hmmm... that compels just a couple more bits of obscure info: :p


"I've found that resample for FSX does such a good job, that it will resample at far greater resolutions than FSX can display."

http://www.fsdeveloper.com/forum/showthread.php?t=3073


...and:


"The sim is stated as having up to 7cm per pixel photoreal resolution. But the FSX.cfg file can be edited to force 3.5cm per pixel resolution"

http://www.fsdeveloper.com/forum/threads/3-5cm-per-pixel.21121/


GaryGB
 
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Thank you so much GaryGB and hcornea for your responses. You've answered my question and then some! I appreciate all of the information!

I've worked a little with SBuilder (the FS9 version) for editing airport background polygons and such, and it sounds like SBuilderX will be very useful for working with FSX as well. I will definitely check out the documentaion that Gary recommended. I've got a little experience with the FS9 resampler and GMax, at least enough to be dangerous!

The project which is near and dear to my heart is to make a "retro" version of O'Hare International in Chicago, in it's late 1970's-early 1980's form. The problem, of course, is getting high-res aerial imagery of the airport from that vintage. So far, I've been able to find 1 meter/pixel Color-Infrared from 1981, though I've asked the vendor to continue to look for true color, and preferably better than 1 meter/pix resolution. They also have some black and white 1 meter/pixel views from the 1970's. There's some beautiful 0.25 meter/pix color stuff available currently, but the airport has seen a lot of changes in the last 30 years! I actually have messed around with trying to backdate a more recent image with Photoshop, but it's just a huge task that doesn't seem very viable. Hopefully the vender can come through with good quality older imagery.

I'm sure I'll have many more questions along the way. Thanks again for your thourough and speedy responses. The knowledge and kindness of the folks here on FSDeveloper continues to amaze me!

Mark
 
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