I’m working on a custom airport, but can’t get the collisions working.
I’ve made a few models using Blender and selection the Collision material in the MSFS properties. However, I can drive/fly straight through all models.
Also, I’ve put in some default wind turbines (simObjects), which I can also fly straight through.
On the apron there are some default light poles and fuel buildings, those are solid. However, once I put a light pole inside one of the turbines, the collisions don’t work anymore.
I would assume there is an issue with all models placed outside of the apron, although it doesn’t make sense (to me).
Does anyone have an idea on how to get the collisions working properly, or in which settings I may need to look?
The collision tick doesn´t seem to do anything. Try ticking “road material” aswell. This way I made solid taxiway bridges for my airport. Now the cars of the street underneath the bridge go crazy, because they assume my model as a “street”, but I does not seem to be a problem when there is no street in the surrounding. Maybe this works for you.
I know this may be a bit late to answer this but I just figured it out
the best way to go about it is to make a collision cage mesh (basically a lower poly version of the model)
I think that maybe MSFS has a limit on how highly detailed a collision mesh can be.
I assume you’re using blender?
if so add a new material to your collision model set the MSFS material type to MSFS invisible, set the alpha to zero and then tick road surface.
I did this on an entire area in italy and the collision model takes on the properties of the underlying roads (so basically cars drive on the roads of my photogrammetry model) its not perfect tho as my model has far higher resolution than the original DEM data so the roads are a bit off.
as HoseBlase says the collision tag does not seem to be working
I have also done this for road surfaces on bridges to good success (add a low poly grid above the road surface and give it the same material properties as above)
in the example image the photogrammetry landscape is 1.6 million polys… the collision model is 4500 polys (just have it nested in the same group as the original model) you’ll only need to include it in the highest LOD group because you’re not gonna hit anything when the lower LOD models are loaded in.
(in the sim you can crash into the mountains , without the collision mesh you would just clip through)
here’s an example image of how I get roads to work on bridges (they also work as a collision model and you can land planes on the bridges)
the other roads are at ground level so you’ll naturally crash into those 
using that method cars will even drive under the girders of the bridges.