Let’s start with the good news, I finished my model of the church in Abcoude. All the textures have been applied as you can see in the screenshot below. But I learned some interesting things while trying to get that far.
Let me start with explaining my approach to texturing the building. I had decided to make separate texture files for each of the different walls. Mainly because I have not yet found a way in SketchUp to define the UV coordinates very accurately. So trying to map a sheet with many different texture elements would become hard that way. If each wall has its own texture though that becomes a lot easier already. And of course I will use the drawcall minimizer of ModelConverterX later on to still make one combined texture sheet for FSX.
One of the things that I encountered is that I needed to position the texture very accurately, because even a small error would result in the textures repeating over the surface and then I can not combine them into one texture sheet in ModelConverterX anymore. So especially for the textures that do not simply fill the entire face that took some trial and error.
One performance related lesson I learnt is that you need to export as COLLADA DAE and not as Google Earth KMZ from SketchUp. When exporting as KMZ (almost) all of the faces are exported double sided, which increases the polygon count a lot. And in the KMZ exporter I could not find an option to disable this, when exporting as DAE there is such an option (and by default they are not double sided anyway). So although it might sound easy that a KMZ has the textures in the same file, it seems better not to use it.
Another performance related issue is that while drawing geometry in SketchUp some additional polygons might be created without you really noticing it. So in the end I spend some time to remove polygons that could not be seen from the outside anyway. I guess this is the price to pay for the easy way to draw the geometry, but it is for sure worth the effort to check and remove such polygons in the end.
So if I look back to this SketchUp experimentation until now I think I have to say that the modelling itself is easier in SketchUp than in GMax (and it seems also more fun). It is very easy to just draw some more geometry. The texturing part I am not so sure about yet, it seems you do not have as much control over that as I am used to. Which can make it hard to make a model with optimal performance for FSX. But it might also be that I still have to learn some more options, so I will continue exploring. For sure it is a lot of fun.
At the moment I am installing the latest test version of the NL2000 scenery, once that is done I will post a screenshot of the church in its proper environment.