possible solution for FSX groundpoly

[BrBlazer]

Thanks mate. Will try it out later on after my work.

Kindly,

Blazer

 

[ted320]

Hey Guys

I'm curious to know how you would draw a long taxiway or runway, how would you split that into smaller sections of less than 100m

TED320

 

[rhumbaflappy]

Hi Arno.

Sorry for the delay.

I hope to play with this today. It is encouraging if we can just take a large poly and slice it in gmax, and then export the slices as one scene... much easier than trying to reference and coordinate dozens of separate 100x100 groundplanes.

I guess the next question would concern layering, to see if that all works... if so, ground polys are OK for at least this generation of FS.

Dick

 

[BrBlazer]

Hi Dick,

I read somewhere I think posted by Arno and it's what I have been using here and works:

4 : ground poly
12: airport ground (taxiways, aprons, etc...)
20: ground markings
xx: taxilines (cannot remember, used 40 in FS9 but if I remember correctly I use something in the late 30's for FSX, will check after work and post.)

EDIT: I also have my ground poly 0.002m above the ground, the aprons and taxiways 0.004m above, ground markings 0.006m above and taxilines 0.008m above. The highest layer is less than 1cm above the ground, which in FS terms can be considered "invisible" difference.

Kindly,

Blazer

 

[rhumbaflappy]

Hi Blazer.

The question is: does FSX have a problem with possibly hundreds of layered groundplane objects ( tiles )...perhaps of FS2002-style BGL?

Dick

 

[arno]

Hi,

For the airport I talked about I have three layers:

8: aerial imagery
12: noise texture
16: aprons/taxiways

All polygons are placed at ground level, so no altitude offsets. If you apply the proper ADDCAT tweak there is no need for that anyway.

I think if I would design a new airport I would use resample for the photo layer, as the mesh technique has improved a lot in FsX. I would only use the Fs2002-style ground polygons for those areas where MS forgot to provide us a good alternative. So for example the high detailed things you can't make with XML code, like good ground markings.

Personally I would not continue designing like we are doing for the last years (with the Fs2002 techniques as the only way). I think we should try to make as much use of the new FsX features as we can. But luckily these old style ground polygons still work for those areas where there is no good alternative.

 

[arno]

Hi,

I'm curious to know how you would draw a long taxiway or runway, how would you split that into smaller sections of less than 100m

Don't know which tools you are using, but as discussed before you can easily slice a polygon into pieces in GMax for example.

 

[rhumbaflappy]

Hi Arno, and all.

I can confirm that simply ensuring the faces of the groundpoly are 100 meters or less, the poly will display correctly using the FS2002 technique ( ADDCAT ).

I used a 10000 x 10000 meter plane with length and width segments of 100 x 100. It's made as a FS2002 BGL. The poly sits on the ocean, centered at N0* E0*. Shadows are OK. The poly seems to cling to the ground.

I had thought we'd need separate objects ( 100 x 100 meters )... but it's not true. We just need the poly faces to be 100 x 100 or less. Perhaps a bit more is OK.



Dick

 

[Thomas]

Hi Arno,

Are there any performance issues with this technique? Because splitting up the planes in Gmax will result in a lot more polygons to be calculated by FS.

For example when I have a photoreal grid of 5x5 km. Before this would be 25 tiles if I'm using tiles of 1km x 1km. 25 tiles x 2 polygons = 50 polygons in total for the photoreal grid.

If you split up these polygons into 100m x 100x, then you would get 50x50 = 2500 tiles x 2 polygons = 5000 polygons for the photoreal grid. Not to mention the increment of polies when you have to split up other ground objects as well (like runways, aprons,...).

So I'm just curious about the performance of this technique...

Regards,
Thomas

 

[arno]

Thanks Dick for verifying the results. It is always good to hear it also works for other people .

 

[arno]

Hi Thomas,

Yes, of course this will have some performance influence. But it is the only option we have, as else we can't use these techniques at all (just try to create that level of realism with the XML code).

Besides that I don't think the effect will be that big. Before the photo tiles were popular, most people used polygons to draw the aprons, grass, etc. These kind of polygons use a lot more vertices than simple squares with textures on it. So the result should not be too bad.

 

[toprob]

I'm putting the finishing touches to the FSX version of my current project, and have managed to get my ground polys working with a combination of techniques -- luckily the airports in the scenery are not very big, so cutting/slicing etc is workable.
However I do lose aircraft shadows on ground polys unless I use DXT1. Does everyone get this result? My nice blended polys in FS2004 will be a bit less realistic if I can't blend them in FSX.

 

[rhumbaflappy]

The above zipped package contains a groundpoly with DXT1. I just changed it to DXT5 on my computer, and shadows worked fine.

Dick

 

[Horst18519]

I seem to have stumbled into this very interesting discussion. It's a lot to read, so let me conclude what I think I found out and correct me if I'm wrong.

- You found a new way of making layered groundpolys for FSX?
- no need to elevate the different layers above the mesh?
- What you do is create not one big textured plane but several 100x100m planes (see Arno's screenshot)?
- Then you use the old compiling method and not XML?
- The result is more promising than with resample or xml-placed groundpolys?

If all of that would be true that'd be really nice.

 

[Gianni]

Hi Thorsten,

yes - I can confirm that this technique works. In my projects (LOWS and LOWK) I used to place big polygons with the photos textured. A single polygon is representing a size of rougly 800m square. With the slice tool in GMAX I cutted these polygons (a little bit work of course) in smaller tiles sized below 100m square (about 90m as far as I remember). It was not necessary to readjust the texture-mapping.

The procedure:
1) clone the original poly
2) slice the cloned poly into proper smaller tiles
3) clone this sliced poly once again (for the following smaller tiles)
4) delete all faces not needed for the first (sliced) poly
5) proceed for the rest of the needed smaller tiles as described under 3)
6) and so on....

The original poly will not be needed any longer (at least not for exporting), but I find it always quite comfortable to have the "big one" stored.

After having finished this boring work I compiled the ground polys with the fs2002 gamepack. Voilá!

http://www.dieter-salzl.de/ensemble.jpg

greetz

 

[arno]

Hi Thorsten,

- You found a new way of making layered groundpolys for FSX?

It's not really new, it is just that SP1 fixed some of the problems we had with this old technique.

- no need to elevate the different layers above the mesh?

No, that is always a bad idea. Ground polygons belong on the ground .

- Then you use the old compiling method and not XML?

Yes, all compiled with the Fs2002 MakeMDL, as the MDL format (Fs2004 or FsX) does not really allow the creation of proper ground polygons. So for that we really need to Fs2002 format.

- The result is more promising than with resample or xml-placed groundpolys?

Compared to resample I think it depends on where you use it. But given the fact that XML (AFCAD style) shows on top of the resample, an additional layer that can be placed above that is very useful. But outside airports I think the resample technique is way better. But when you want to add small details and markings to an airport, I think this is easier.

Comparing to XML placed groundpolygons, not sure what you mean there. The XML aprons etc give you hardly any control over the texture or the texture mapping. So they are simply unsuitable if you want to make a high detailed ground layout.

 

[rhumbaflappy]

- What you do is create not one big textured plane but several 100x100m planes (see Arno's screenshot)?

Hi Thorsten.

The polygon needs to have faces ( segments ) of less than 100 meters. You don't need thousands of polygons... just simple polys with many faces. I think you can use the divide function to also accomplish this, as well as slice.

Dick

 

[toprob]

The above zipped package contains a groundpoly with DXT1. I just changed it to DXT5 on my computer, and shadows worked fine.

Dick

Thanks for that, Dick. I get the same result. However when I add an alpha mask then the shadow goes again.

 

[Horst18519]

Thanks for the replies. And sorry to ask a simple question again:

Do I have ot create an api? Or must I tweak the compiled mdl/bgl?

Please give me a small boost for the export steps again.

 

[rhumbaflappy]

Ah!

Then the alpha channel breaks the shadowing, regardless of the format?

Now I wonder if an attached platform would bring the shadow back. When we first got platforms, they would display a shadow, even if it was suspended in the air.

Dick