Sorry, I see on rereading you specify fs9.
Tieton State would be a nice project for you! To make a photoreal ground poly in fs9, my best results come from designing in gmax.
first you want great source photo, and you want that photo to be projected in wgs84 datum, geographic projection. Converting the photo is simple if you have a GIS tool, or a hassle if you don't. I can help here if you need it.
Once you have a good source photo, you need to be able to relate the geographic coverage of the photo to pixels, and also to meters.
Again, easy to do with either a good gis tool, or with very acurate information about landmarks contained in the photo. One source of information is the airport/facilities directory, which shows runways in length units, meters or feet, and you'll find using the runway ends to be a pretty good set of landmarks.
I usually make an excell spreadsheet in which i list the 3 units of distance between a horizontal set of landmarks and a vertical set of landmarks. 1. distance in degrees 2. distance in meters 3. distance in pixels
With that, you can now calculate 4 ratios that are useful, 1. degrees/pixel (horizontal), 2. degrees/pixel (vertical), 3. meters/pixel (horizontal), and meters/pixel (vertical).
That's the hard work.
Now, you look at your photo and let your artist side take control for a minute, decide where the outside edge of your project is based on the photo.
Crop the photo to that extent.
Now a little planning is needed. You'll need to eventually make textures of parts of this image, so the overall image extent is easiest if it consists of an even multiple of the texture sizes, 256x256 pixels, or 512x512 pixels or 1024x1024 pixels, or rectuangular combinations. So I make a choice of texture size, I usually use 512x512. Then I'll make a multiples chart in excell, by listing the product of 512 x 1,2,3,4,.... Then I know the extent I've chosen for my image, and I'll choose the closest multiple as the ideal extend of my image. Now, if you want, you can go back and crop the image bigger or slightly smaller to match, or you can just add dead image pixels to the image, we'll deal with making it look nice later. If you choose to just fake the image into the right size, just add canvas, do not "resize" the image, which resamples it. Leave the new "border" blank. Whatever the default shows it is fine. That part wont make it to the final result. The end result is a photo with a width and height that's a multiple of the texture size.
Your photo width in pixels, times your horizontal m/pixels tells you the width of the gmax polygon, similarly your photo height in pixels times your vertical m/pixels tells your the height in meters of your gmax polygon. Now go to gmax and make a plane using the meters from this exercise. set your width and height subsections to the multiples of your texture, so that you have individual polygons for each square of the texture you plan to drap on the polygon.
Make your textures from the main image now. You cut up the texture per your plan.
Now you multitexture the plane. I do a wierd way of this, others are more elegant. I go into poly mode and "detach" each of the poly sections, texture each one with the material appropriate for that segment. Then when all done, I "attach" the polys together. This automatically makes the material a multi-material.
Now you have a square plane with an awesome high res image of your airport and surroundings but with an ugly border.
What I do now is build a cutting tool in gmax. The tool takes the shape of the real extend I desire to see displayed in fs9, and then extends beyond the edge of the plane. I do this tool in quadrants as gmax can be fussy about complex shapes doing boolean cuts. So, I make a 2d line over the edge of the place I want to end the polygon, and when I get about a quarter of the way around, I just turn the line to go beyond the edge, and then continue around until the shape covers 1/4 of the area of the plan that I'd like to dispose of.
Now, I extrude the shape. Now I go into "border" mode, and highlight the open edge of the extrusion and click "cap". Now the tool is a solid. Position the tool in z, so that it intersects the plane. Now select the plane, and tell gmax you are making a boolean object. Select the tool as part "b" and select "cookie cutter", and then subtract b from A. Voila...your plane has 1/4 of it shaped irregularly, and still decorated with high res imagry. Now repeat for the other 4 quarters, and you have a beautiful ground polygon ready for export.
Export needs to be done with the fs2002 makemdl, with a makemdl.cfg line inserted that instructs Keepfiles=1. (I may have that inaccurate, this is typed from memory, I'm not at my dev computer) You need to establish a ref point for the plane prior to export, which will have a lat/long that agrees with fs world. This can be the end of a runway. The natural ref point won't be there but you can more the ref point using the motion button on gmax, and the affect pivot only setting. Provide that coordinate pair to the export screen in makemdl.
Once you export, you will have an asm version of the export file, and an asm_0 version as well.
Find the code call "addobj......", and change that to addcat.....and you can add a comma and a level here. Then delete the shadowcall statement. Arno has a seperate post on this site that details this tweak.
Then recompile using bglc.exe
Now you add your bgl file, and enjoy the result.
Bob
PS...forgot to mention that you still need to make fs textures of the gmax material squares. convert them to dxt1 using imagetool.
I did a search here but a lot of questions and answers are of course contextual and do not depict the whole picture.
