I think I have figured out where my confusion is coming from, and I thought I would chime in to relay this information so that hopefully the next iteration of the CLT Guide can be a bit clearer.
In the chapter about G and O files, there is a section that says the material texture of the Grass object is ignored by the game. Here is the exact quote from the manual:
To properly show the grass effect, the object needs to be applied UVW mapping. This procedure is
different in each modelling application. Depending on application used, UVW mapping can be done
with or without a real texture assigned to the object. The texture assigned to the object is ignored in
game and default grass effect texture is used
The section that talks about the Asphalt object doesn't give much additional information on the G object - but does state :
However, the detailed surface structure is shown in the same style as for grass and the same UVW mapping process applies there
too.
In my head, I took this to mean that the texture assigned to the Asphalt object was ignored / not used - and the only thing used was the game's internal tiled asphalt texture.
The reality is a little more complicated - and I am still not quite sure of the details, but I found out by accident that if you give the Asphalt object an actual material texture , it is indeed used by the game - and this texture is what is used to produce the "Muck" texture on the Slovenia runways.
What I am not clear on is how this texture is composited with the internal tiled asphalt texture. Is there a way to specify the opacity of the assigned material texture - or is this hard coded by the game engine Is this "Muck" texture covered in the Guide? I was not able to find any info.
This seems like a area where the next version of the manual could offer much more information and clarity.
Also, in "reverse engineering" some of the Slovenia airports, I noticed that there are some really awesome and interesting objects included in the Airport O files for Slovenia. I think I have read that we are free to reuse Slovenia landscape objects - but these objects embedded in the airport O files are not accessible. Are there any plans on adding these objects to the Scenery database - or maybe making the .obj files available so we can extract the objects that match our scenery?
I'm making progress.
I am now even able to take-off and land on my airport's silly sloped runway - though there is still quite a bit of bouncing going on.
Oh, and one more request... I find the deciduous trees used by the forest map to be way too short for the area I am trying to model. We get some pretty dang HUGE trees - looking outside my window right now, most trees are in the 80-100 foot tall range - i.e., our trees are way taller than our houses - so a way to specify the scale of trees would be awesome - just like we can scale individual landscape objects.