Obsolete: With world update 6 this package has become largely obsolete and you should remove it from your community folder. I'll leave it here for the moment for potential niche applications (italian alps, lightweight offline mesh, ...?)

When/if I take this further, there will be a new showcase area.

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Experimental CGL tile for switzerland (120221)

Another mesh covering switzerland and parts of its surrounding countries. This is released mostly as a showcase but also because I think it might be good enough for some people to use now - I don't want to sit on it forever.

We would be very interested in any feedback (problems, quirks, observations) to help us understand the (undocumented) CGL format better. Also see "known issues" below.

What is it?
It's an elevation mesh in the CGL format. 

What area does it cover?
A CGL file has to cover a whole level 6 quad tile. As switzerland fits neatly into one of these tiles this package contains only one CGL file (quad 120221). This tile extends quite a bit into the neighboring countries in the north and the south.

What's the difference to all those other meshes popping up lately?
As far as I'm aware, apart from ItalyDEM (by Sprighlyoldman) and "DEM for Finland" (by muumimorko) all other so called "mesh" sceneries are based on a technique using grids of terraforming heightmaps. While a CGL replaces the original base mesh heightmaps are just modifiers of the base mesh. 

Is there a problem with the heightmap technique?
The story here is that there exists a freeware tool now that makes it relatively easy for anyone to create those heightmap sceneries. The problem is, that these heightmaps were not intended for large scale mesh work so there are a few issues (not optimized for memory - both meshes are loaded, not optimized for runtime, for some people artefacts appear where the base mesh doesn't get transformed in time, interference with terraforming of other sceneries - therefore these meshes need to have "holes" to allow for other sceneries to exist properly.

Are CGLs the perfect solution then?
In theory yes - it's the format that has been engineered for large scale mesh work. In practice there is the main issue that the format is undocumented and needs to be reverse engineered (almost all of this is courtesy of muumimorko). There are no ready made polished tools for CGL generation - so the process is quite a bit more involved. A few things are still not properly understood.

Is there any risk using the CGL sceneries?
Well, it's experimental. If you have problems with it just delete it. In the hundreds of times I have loaded various incarnations of test meshes I think I never had a crash or even unexpected/inexplicable behaviour (beyond the bits that are not understood yet).

What's the difference to the same tile contained in the ItalyDEM scenery?
ItalyDEM (as of now) was created with an old version of the tools by muumimorko which blurred the lower LODs - with the effect, that the high detail is only visible from close up. The mountains get more and more flattened the further away they are. 
This scenery is completely redone using my own tools and better DEM sources (SwissAlti3D for Switzerland). Downsampling the lower LODs has been improved (no more flattening) and the resolution has been increased by one level (~13m).

Can it coexist with ItalyDEM (which contains the same tile)?
Looks like it.

Can it coexist with heightmap based sceneries?
There's no reason why it shouldn't work as the two work on different levels (heightmap overrides base mesh).

What's the future?
Higher resolutions, including better DEM sources, mixed resolution/adaptive pruning of unnecessary LOD tiles, better downsampling algorithms ....
There's plenty to do and so little time.

What's the far future?
Once microsoft streams the whole world in high resolution from their servers all this will be obsolete. Tomorrow? No.

A note to airport/scenery designers:
It's most likely not this scenery's fault if it messes up your airport. Rather, you could use this as an indicator that your airport is not future proof and will also misbehave with a future world update which includes the swiss territory. In which case you could make use of this CGL to help you fix it.
Proposed approach to make an airport look good and be compatible with the current low quality mesh, a future high quality mesh, this CGL and heightmap-meshes:

• create a heightmap (using the nool tool and the swissAlti3d DEM) for roughly the perimeter of your scenery. This will bake in the correct terrain with your scenery. Consider replacing your existing flattening polygons with such heightmaps, because totally flat airports are totally unrealistic and totally boring. Don't bother with extreme resolutions for the heightmap, because heightmaps can only influence the mesh up to a certain level (I think LOD22 / 6.5m - but probably depending on the resolution of the base mesh).
• if necessary apply further terraforming on top of this
• if you want your scenery to be compatible with large scale heightmap-based sceneries adjust the priority of your terraforming elements to be higher than what they use (which level?).

Technical:

• LOD13/21 CGL mesh (~13m resolution at these latitudes)
• Generated with my own tools (nowhere near good enough for anyone else to use at the moment)

Known issues:

• Doesn't align well with the next tile at the northern edge. Not sure why yet.
• Around the italian border there seem to be some small areas that are not claimed by either country (pinholes in the scenery - mainly to france and austria).
• Areas that already had a world update (France...) and therefore have higher LODs than this mesh will switch to the streamed mesh after this mesh runs out of LODs. There are some areas (french alps near italian border) where the high LOD streamed mesh has very bad detail. So when getting close it looks like it's switching LOD in the wrong direction. This is mostly a problem with the streamed scenery and can probably only be resolved by supplying equally high LODs.
• Sharp edges/ridges can have some kind of sawtooth effect due to the applied upsampling filter. Asobos high res meshes exhibit this less - I think their remedy might just be to supersample the source meshes or blurring/softening their meshes. Some room  for experimentation...

DEM sources:

• CH/LI: SwissAlti3d (2m resolution) Federal Office of Topography swisstopo.
• IT: TinItaly 10m DEM (Tarquini S., Isola I., Favalli M., Battistini A. (2007) TINITALY, a digital elevation model of Italy with a 10 meters cell size (Version 1.0) [Data set]. Istituto Nazionale di Geofisica e Vulcanologia (INGV). https://doi.org/10.13127/TINITALY/1.0)
• AT: "Digitales 10m - Geländemodell aus Airborne Laserscan Daten" (https://www.data.gv.at/katalog/dataset/dgm)
• DE/FR: "Digitale LiDAR-Geländemodelle von Europa | Digital LiDAR-Terrain Models of Europe" by Sonny (https://data.opendataportal.at/dataset/dtm-europe)

Further credits:

• Muumimorko the pioneering reverse engineer of the CGL format.
• Sprighlyoldman and his ItalyDEM scenery showed off the potential of the technique.
• theisomizer (and others on fsdeveloper). Some kind of mastermind that provides valuable insights.

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CGL DEM Switzerland

An experimental CGL elevation mesh add-on covering Switzerland and neighboring countries, released as a showcase and potential usage. Different from heightmap-based meshes, CGL format offers a more optimized solution for large-scale mesh work. Users are encouraged to provide feedback to enhance understanding of the CGL format and its applications. It aims to improve mesh quality with better DEM sources and resolution for a more realistic flying experience.

Version History

No version history available.