Aaaaaahhh ! I didn't read carefully. It's ground polygons. I thought it was photoreal terrain.
Yeah you're right, if the terrain is not flat, it takes a lot of time to generate meshes and beta test the scenery to make sure the polygons blends well with the surrounding terrain.
Okay. One workaround is use VTP polygons with SBuilder to convert the bitmaps to VTP indices. That way you don't need to create polygons while the photo terrain uses the mesh. But I'm unsure wheter you can have seasonal variations with that technique, never tried.
Otherwise, to ease things, flattens every possible surface and use only two triangles quads per texture sheet. I use GMax to create the squares for the 1024x1024 textures. Areas where flattens cannot be applied must be created triangle per triangle. It also depends on whether you want to make your ground "landable", ie platforms meshes (which should be processed apart, while the textured polygons are just visual object with collision disabled)
Shuttering is an FS9 issue on ground polygons. To avoid them :
- use mipmaps (blurry textures on some video cards - unfortunately)
- Convert 32bits to Dxt3
- remove crashtree in ASM for your ground poly
- I don't remember which one is better : using multimaterial on one single entire ground polygon and various textures like you did, or separate each square surface and export them one by one with one single drawcall per square surface. I think the later is the worse but I've never used more than a dozen 1024 sheets textures, so never made the comparison.
- One classic (but uglier) workaround is not use tons of 1024 textures. Instead, create as many small tarmac/grass/whatever generic ground textures as required (to be tiled), either programmatically, or manually adapting each from small portions from the already available satellite imagery. Save that as 256² or 512² bitmap generic. Draw polygons limits for the various ground textures perfectly following your initial ground mesh, then apply the textures, tiled, per area. What you get is very sharp ugly edges between areas. Create low resolution textures of your initial satellite imagery, by reducing the initial size by a factor of 2 or 4 (you save from 3 to 12 times memory consumption) Then recreate new 1024² textures sets from the reduced resolution, and apply them to your initial poly mesh with a translucent factor to make them blend above the tiled generic grounds (remove unnecessary triangles from the mesh) Export with FS2002 SDK and custom ASM edits or use MCX (never tried though, always did it kind of "manual") That way, you'll recreate the general photoreal aspect of the airport, not as beautiful as with the original very detailed textures, but using much less memory resources. If you aren't happy with the global blending transparency (which is understandable) you should treat the blending through alpha channel, per low res texture... Lot of work.. unless you have a graphic tool that can create adaptating alpha using beziers curves. Photoshop can, but I use a tool of mine instead.
- along with the previous, you can aswell process your satellite imagery through ressample SDK to have a third (very low resolution) layer below the two other, then make your generic tiled textures a bit translucent. That way, you take advantage of the auto generated "noise" (granularity) of the terrain texture, to reduce the look of the blurred pixels. And, when you have terrain LODs shiftings, the defaut terrain doesn't bleed throught that much.
FS9 has a lot of drawcall issues and there are things you simply can't avoid (yeah, there are many great improvements since FSX - FS9 is more than ten years old technology)
60 1024² tiles in view is 60Mb in memory at Dxt3 or 246Mb at 32Bits. Not really a big deal unless you have many detailed structures, library objects, AI traffic and other terrain and environment addons (plus the sound and effects files loaded in memory and perhaps one PMDG user flyable, it quickly rockets...). And I doubt FS9 can handle extended memory anyway (no matter you have 4, 16 or 32Gb RAM, it's like you are limited to 3.7Gb).
If you must use the 60 hires textures for product quality, there's nothing much you can do, except reducing memory loads elsewhere :
- increase LOD shifts from usual 3 LODs to 6 for structures, vegetation, light poles, various objects
- use visibility conditions depending on user point of view
- reduce texture count by improving the used surface per texture
- select framerate friendly libraries or create new ones with improved LOD-ings and textures usage
- Reduce drawcalls by grouping every structure using the same texture in one single mdl export
- use less keyframes in animations wherever possible
...
- by the way, delete unused materials before exporting any object to mdl. FS constantly tries to find the missing textures; at least, for aircraft models I'm sure of.
EDIT : I guess what I've just written is exactly what you wanted to avoid (massive work) Different technologies requires different processings. FSX capabilitites is wider than FS9 is able of. That's also why I suggested to keep things simple. The more you create wonderful things for FSX, the more you have people moving on and go FSX/P3D. I will, like anyone else. I think after this, it's clearer why I don't demand you to have support for FS9. Reducing quality for better performance may not serve you. Instead, one can volunteer himself to carefully go through the whole process to fill the gap, rather than forcing you to find time you may not have, compromising the project with delays and mixed results. Supporting both FS versions is indeed very difficult.
(I should have put a nice smiley and I reckon putting some text in bold could be interpreted as shouting - I wasn't, I just wanted to highlight the correct decision to take)