KORD - Mesh/terrain flattening problem

  • If you download Oldar's KORD model you'll see a problem between 10L and 10C - there's a small mountain between these two runway ends. Presumably the mesh isn't strong enough to flatten the terrain. Any ideas anyone?

    Download full model here: http://www.fscloudport.com/icao/kord.htm

    .AC source file attached

    Phil

  • Probably a solution is here:

    Creating terrain heightmaps

    Cheers, Ed

    Does it really need handling that way? I wondered if there was a way of strengthening the mesh flattening. Double layer?

  • Ah,

    I just saw this thread.

    I know that airport__runway does much stronger flattening than airport__outside. I already had another case, where outside was just not enough for ground flattening.

    So there are 2 possibilities:

    1. Try to refine the elevation mesh data as shown in another thread.

    2. Create __airport__runway mesh between the 2 runways, make it partially a taxiway and partially a green surface.

  • I've encountered this issue quite a bit with those backcountry airstrips I've been playing with. Like Rodeo said, one way to deal with it is to define larger areas as airport__runway, beyond just the runways themselves. I've actually covered very large areas as airport__runway and it doesn't seem to have any negative effect on how the airports are built in the sim, it just flattens the terrain more.

    There is one big problem with this trick though -- unlike airport__outside, when you define things are airport__runway it doesn't let the original imagery show through, so you have to apply an image to texture it. I've dealt with this by actually re-mapping the orthophoto scenery as textures in AC3D (honestly, a huge pain and takes a lot of time, far from ideal). AeroFly also seems to render texture colors quite a bit differently than terrain imagery, so I figured out the right combination of adjustments in photoshop to make the mapped textures look identical to the original orthophoto scenery. I had a thread a while back where I explained this and asked IPACS if they'd consider adding an option to allow airport__runway areas to be transparent when converted, or allow us to define a smoothing strength of the airport__outside regions.

    The best way I've found to deal with it so far is definitely by refining the terrain heightmaps. It's actually a lot easier and faster than re-texturing the areas with the orthophotos, and the end result is a lot better too. Instead of forcing spiky terrain to flatten, you end up with a ground surface that looks more realistic and is already smooth enough that the normal runway flattening works perfectly.

  • Also if you'd like, I can see about getting you an improved terrain mesh for that area, which we can probably freely distribute since the USGS data is open to the public. The thing to be careful of though is the short 'invisible wall' that it creates where the refined mesh merges with the default mesh, so we'll have to make sure the refined mesh extends reasonably beyond the airport where nobody will be colliding with the invisible wall on approach.

  • I've encountered this issue quite a bit with those backcountry airstrips I've been playing with. Like Rodeo said, one way to deal with it is to define larger areas as airport__runway, beyond just the runways themselves. I've actually covered very large areas as airport__runway and it doesn't seem to have any negative effect on how the airports are built in the sim, it just flattens the terrain more.

    There is one big problem with this trick though -- unlike airport__outside, when you define things are airport__runway it doesn't let the original imagery show through, so you have to apply an image to texture it. I've dealt with this by actually re-mapping the orthophoto scenery as textures in AC3D (honestly, a huge pain and takes a lot of time, far from ideal). AeroFly also seems to render texture colors quite a bit differently than terrain imagery, so I figured out the right combination of adjustments in photoshop to make the mapped textures look identical to the original orthophoto scenery. I had a thread a while back where I explained this and asked IPACS if they'd consider adding an option to allow airport__runway areas to be transparent when converted, or allow us to define a smoothing strength of the airport__outside regions.

    The best way I've found to deal with it so far is definitely by refining the terrain heightmaps. It's actually a lot easier and faster than re-texturing the areas with the orthophotos, and the end result is a lot better too. Instead of forcing spiky terrain to flatten, you end up with a ground surface that looks more realistic and is already smooth enough that the normal runway flattening works perfectly.

    these hard learned lessons are pure gold!

    No need for a better heightmap thanks. I'm more concerned about the overall process than this particular incident. I think it will be more practical to apply taxiways/concrete to force it down.

  • If the real world runway is actually "bumpy" and you don't have better local mesh data, an idea might be to design it as airport__outside to soften the flattening. Then, the runway might be added as a decal, a simple textured rectangle - I think decals are being displayed above airport--outside ground (to be confirmed). Some care might however be needed to soften the runway edges transitions...

    To be tested also is whether an airport__runway zone (even tiny) is mandatory or if the complete AD area may be designed as airport__outside...

    My 2 cents

    Antoine

    Config : i7 6900K - 20MB currently set at 3.20GHz, Cooling Noctua NH-U14S, Motherboard ASUS Rampage V Extreme U3.1, RAM HyperX Savage Black Edition 16GB DDR4 3000 MHz, Graphic Card Gigabyte GeForce GTX 1080 8GB, Power supply Corsair RM Series 850W, Windows 10 64 bit.

  • My experience of adding asphalt as a decal is that decal introduces a lot of reflective behaviour that looks weird. I think decal is expected to be white or yellow and quite reflective.

  • thanks for that input.

    Config : i7 6900K - 20MB currently set at 3.20GHz, Cooling Noctua NH-U14S, Motherboard ASUS Rampage V Extreme U3.1, RAM HyperX Savage Black Edition 16GB DDR4 3000 MHz, Graphic Card Gigabyte GeForce GTX 1080 8GB, Power supply Corsair RM Series 850W, Windows 10 64 bit.

  • thanks for that input.

    My request to IPACS to make my FSCloudPort project more effective is a new option like [decal] but without reflections called, say, [layover] so you could use __runway over an entire airport to flatten it then lay the asphalt at 0.1m using [layover] and finally overlay with [decal] at 0.4m.

  • My request to IPACS to make my FSCloudPort project more effective is a new option like [decal] but without reflections called, say, [layover] so you could use __runway over an entire airport to flatten it then lay the asphalt at 0.1m using [layover] and finally overlay with [decal] at 0.4m.

    A too strong flattening is a rather bad thing for airports, since they're almost never flat IRL.

    MS used to force flattening airports in FS to ease up AI traffic integration, with the flatten level set at AD reference altitude. the stock sceneries featured a rather loose mesh resolution (39m at best, ususally worse) so the flatten didn't cause too much troubles except the runways had to be flat.

    As soon as you come with higher resolution meshes you would get the infamous "carrier-effect" we had to solve by editing so-called slope files (hand-made mesh to soften the flatten integration).

    LM is apparently trying to get rid of flattens for a next version of P3D without loosing AI traffic, let's see what comes out.

    One of AFS2's strength is the ability to feature sloppy runways - there's no AI traffic issue. We should check if the airport__outside flatten is mild enough to both keep the terrain natural shape while preventing bumpy landings, without having to feature a fully-modeled 3D runway...

    Cheers

    Antoine

    Config : i7 6900K - 20MB currently set at 3.20GHz, Cooling Noctua NH-U14S, Motherboard ASUS Rampage V Extreme U3.1, RAM HyperX Savage Black Edition 16GB DDR4 3000 MHz, Graphic Card Gigabyte GeForce GTX 1080 8GB, Power supply Corsair RM Series 850W, Windows 10 64 bit.

    Edited 3 times, last by Trespassers (April 10, 2018 at 5:16 PM).

  • We should check if the airport__outside flatten is mild enough to both keep the terrain natural shape while preventing bumpy landings, without having to feature a fully-modeled 3D runway...

    I have tried this, and I think all the combinations of ideas I've seen mentioned in this thread, and I can say it really depends a lot on what the un-smoothed mesh looks like to start with. If you're dealing with significant faceted lumps or spikes, the airport__outside smoothing usually is not enough to correct it on its own and make the surface land-able.

    The airport__runway does preserve some small 'sloppiness' of runways, like elevation changes. I have some sloped backcountry airstrips where it has worked quite well, but it required me first refining the terrain with a better surface mesh.

    By far the most realistic surface I've gotten for unpaved runways has been using a higher-res topo mesh to start with, and then using airport__outside on top of that. This has given me unpaved airstrips that do make the aircraft appear to bump and vibrate but not so much that you're getting kicked into the air repeatedly.

    My request to IPACS to make my FSCloudPort project more effective is a new option like [decal] but without reflections called, say, [layover] so you could use __runway over an entire airport to flatten it then lay the asphalt at 0.1m using [layover] and finally overlay with [decal] at 0.4m.

    I'd still like to see a way to define areas as __runway while still leaving them transparent so the original imagery shows through. (Or create a new class that we don't call __runway but still uses the same flattening strength, or give __outside an adjustable flattening strength). In some cases where things are really lumpy, you need to define the __runway areas beyond even the actual runways and taxiways to get things smooth enough. In this case, you're stuck with remapping textures to get your original imagery to reappear.

    FWIW, you can make the 'decals' look like you want by using Photoshop, and first adjusting the image with Exposure of -2, and then applying Contrast +10. This is what I've used to re-map orthophotos back onto my large __runway areas and it gives an appearance that is almost indistinguishable to the normal scenery. I realize this probably isn't helpful for an automated tool like FSCloudPort, but for anyone trying to brute-force it right now it's one solution that works.

    Also, you may already be aware, but you don't need to adjust height offsets of decals to change their appearance order when converted. Using the __priorityX tag on the end of the decal name determines its stack order in the sim, where X is the priority number.

  • By far the most realistic surface I've gotten for unpaved runways has been using a higher-res topo mesh to start with, and then using airport__outside on top of that. This has given me unpaved airstrips that do make the aircraft appear to bump and vibrate but not so much that you're getting kicked into the air repeatedly.

    That's exactly the aim. So far in my modest AD design testing, I defined a paved runway as airport__runway, while the grass runway belongs to airport__outside, but it's already too smooth for the aircraft to bump and vibrate like on grass.

    What about airport__apron? can anybody tell how strong is the flattening compared to __runway or __outside?

    Cheers

    Antoine

    Config : i7 6900K - 20MB currently set at 3.20GHz, Cooling Noctua NH-U14S, Motherboard ASUS Rampage V Extreme U3.1, RAM HyperX Savage Black Edition 16GB DDR4 3000 MHz, Graphic Card Gigabyte GeForce GTX 1080 8GB, Power supply Corsair RM Series 850W, Windows 10 64 bit.