Scenery disappearing under certain angles P3Dv3.2

[Dimus 2]

I do not post here often but I have posted this in LM forums, FSDeveloper and ORBX forums but got no reply so far so though that maybe some good soul here might have a suggestion.

 

This issue concerns a custom scenery of my home airport LGTT, Tatoi AB, that I made back in 2010. I recently updated it mainly for P3D but also to make it fit better with ORBX Global + Vector + OpenLC EU, which is the best combination so far for my country. Everything works great in FSXA, FSXSE and P3D 2.5. and used to work in 3.1. However, in 3.2 I have the problem that is shown on the following video:

 

 

As you can see all the airport disappears under certain angles, mainly low angle and when looking north. All is OK when looking south. The LC polygons I have defined remain visible. ORBX Global, Vector and OPENLC EU are active. The strange thing is this: I tried deactivating the ORBX libraries entry in the scenery library and the problem went away. 

 

Again, the problem exists only in P3D 3.2, all other sims are fine.

 

The scenery is made mainly with ADE and using the FSX SDK. Do you think recompiling using the latest P3D v3 SDK would help?

 

[jabloomf1230 2,445]

This is a known bug in P3d that has persisted since FSX. It even showed up in the initial releases of ORBX Meigs Field and there are several threads about this issue on both the official ORBX and LM message boards.

 

LM has had no luck in reproducing the bug and the prevailing opinion is that it has something to do with the number of objects used in certain 3rd party airports.

 

Since you authored this airport, try splitting up the objects into more than one file, rather than just a single OBJ file or BGL library. Also, avoid using large numbers of a single object like a car or a tree.

[sightseer 895]

 

there is some sort of taxiway markings problem that exists at Chicago Midway in orbx FTX Global. I did not check it with default P3d but I suspect its v3.2 specific because it was always fine before.

 

If you go to spot view and rotate around the aircraft, different lines and markings will pop in and out.

From cockpit view, I first noticed the issue when the runway markings disappeared as I took off.

 

I don't think its just your airport.

[jabloomf1230 2,445]

I don't think its just your airport.

 

 

It's not. But what you pointed out seems like a different issue. Often when their are multiple 3rd party versions of a specific airport, taxiways and taxiway markings tend to get all jumbled up as the two or more addon airport versions "fight for supremacy". Was that issue occurring with the default KMDW?

[johnlgjm 9]

I can confirm that I have also experienced this. For me it is at KECP in Panama City Florida. This is one of the airports from the Orbx North American Freeware Pack. It happens as you get close to the end of runway 34. The txiway and runway will just dissapear. As you pan left or right, the runway and taxiway will reappear. Look back strait and it's gone again. Makes holding short a little tough! I have never had an answer as to why this happens. I know this isn't helpful for fixing the issue, bit just further confirmation that it is not just your custom airport.

 

John

[Dimus 2]

Thanks guys! So far yours may be the most helpful responses I had, especially jabloomf123. Truth is that I use a grass object on the taxiway edges in a bgl of its own that is being repeated several times in the scenery. I will try deleting or reducing it to see if it makes a difference. Still this is a 3.2 issue only though as everything worked fine so far since 2010.

[jabloomf1230 2,445]

The issue is fairly uncommon, but when it occurs it is very annoying. I assume that you found the threads on the ORBX and LM forums. They aren't very helpful, but at least they confirm that the issue is real. There are also threads on FSDeveloper but they are fairly old and are based on the issue in FSX. I'm surprised no one there pointed them out to you.

[Dimus 2]

Some just did point out such a thread at FSDeveloper. It seems to be related with many instances of the same object ID which is the case in my scenery. I'll try reducing and see how it goes.

[jabloomf1230 2,445]

Ha ha, that was me.

[Dimus 2]

I should have guessed..  Thanks Jay! 

[Dimus 2]

I deleted all the grass objects that were repeated from but it did not solve the problem. Also compiled with latest SDK. I think I'll leave it as is. I was planning to redo this from scratch anyway as I have learned a lot since 2010. Thanks for the help 

[Dimus 2]

Just as an update, athough my question at the P3D forums was not answered directly, it seems another developer had a similar problem and the answer to him was that this issue is related to zbias and will be solved in the next patch. So it is not the same thing that happened in FSX in the past, related to multiple instances of a GUID, but a different P3D v3.2 related thing.

 

My thread: http://www.prepar3d.com/forum/viewtopic.php?f=6307&t=119373

 

The other thread: http://www.prepar3d.com/forum/viewtopic.php?f=6307&t=119419

[jabloomf1230 2,445]

That's definitely a different issue than what has been reported for objects disappearing, as that problem relates only to airport ground polygons.

[gregory.goodwin1 54]

I have had the same problem and just figured out a solution.    The problem seems to be very location specific.  I notice it more often when the default airport I am replacing is mislocated.  When I try to put it where it is supposed to be, I often have the problem as seen in the video above.  When I move the airport to a nearby location (usually about 10K to 20K feet away, the problem does not occur.  It seems to be more prevalent with smaller airports, at least for me. In my case, objects don't disappear, only runway and tarmac surfaces disappear and only when viewed from a certain direction at certain locations.  Anyway, the fix I have found is to draw a small tarmac surface about 20k feet away from the airport.  It doesn't have to be very big so you won't really notice it otherwise.  That worked well for me.

[gregory.goodwin1 54]

Just a couple of additional points on my earlier post for clarification.  I am talking about creating airports with Airport Design Editor.   There are two types of polygons that you can create in ADE, a tarmac polygon and a ground polygon.  This fix requires the tarmac polygon to be used.  Tarmac polygons have a list of textures that can be applied and it doesn't matter which texture you use.  As a general rule of thumb I put the polygon about 4 runway lengths away but I haven't experimented much to see how far it really has to be to work.  You should be able to modify 3rd party airports with this issue if you crack open the correct .bgl file with ADE and then make the modification above.