FSXA Satellite image; Ground poly or Photoscenery

[jtanabodee]

Hi,
I went to the Aerosoft preview forum and found that is developing. Mega-airport Brussel.

According to the forum, they already made ground poly for this airport.

To my surprise, I thought it is better to use Photoscenery instead of ground poly. May be I'm wrong or.....get confused.
I would like to know other people opinions about this.

Do you use ground poly for your satellite photo in FSX?
To my knowledge, there are pros and cons.

Pro: The picture will be crisp and clear.

Con: Drawcall will be much more than using photoscenery and drag down fps. It is not as easy to make as photoscenery.

Any more ideas?

Regards,

 

[hcornea]

The photo you have shown looks to be a groundpoly for runway, apron and taxiway surfaces only.

It is likely to be overlaid on photoreal resampled scenery.

This is the way I would do it, and I had trouble interpreting the poll. I chose: 1. Yes.

 

[Southwest]

I find it surprising that so few developers place aerial imagery using GMAX.

For me, I see no drawbacks; The aerial imagery is cut down into approximately 50 planes depending on the size of the airfield, so it stays sharp, there's no long distance blurring, but more importantly, it sits above the AFCAD file which allows me to utilize the detail in the imagery for my taxiways and runways. I can't say I've noticed any performance drop.

An example can be seen in my most recent project which employs this method.

The idea of placing imagery using resample seems a little complicated. Particularity when it comes to lining up and creating your ground polygons - I'd rather have everything contained in a single GMAX file that can all be editied at once.

I've only ever used the resample technique once, it was my first project and also my last project that employed it.

 

[jtanabodee]

The photo you have shown looks to be a groundpoly for runway, apron and taxiway surfaces only.

It is likely to be overlaid on photoreal resampled scenery.

This is the way I would do it, and I had trouble interpreting the poll. I chose: 1. Yes.

The question is about ground poly for satellite photo. Not ground poly for taxiway and runway.

I think the photo is for satellite photo using gmax as ground poly. Because the edge has white unused area that would be alpha channel. If you go to their forum, there is another picture for gmax ground poly for taxiway and runway, very complicated and so much detail.

 

[Shaun]

I don't like the look of it at all; there's a Moire pattern over them a little. Plus, The performance seems to take quite a hit. Seasons are hard to implement (though I think the ground poly wizard does them now). You need to cut up the image etc...

I find no difficulty with resample and lining up Ground Polys with using the coordinate converter. Of the scenery add ons I have I prefer the ones that use photoscenery.

 

[jtanabodee]

For me, I see no drawbacks; The aerial imagery is cut down into approximately 50 planes depending on the size of the airfield, so it stays sharp, there's no long distance blurring, but more importantly, it sits above the AFCAD file which allows me to utilize the detail in the imagery for my taxiways and runways. I can't say I've noticed any performance drop.

It is true about the the clear and sharp image. Howerver 50 planes of ground poly has 50 drawcalls already.
The issue of AFCAD file is true. I wonder if it is possible to use path instead of taxi way line in AFCAD to make the photoscenery visible under ground poly taxiway.

The idea of placing imagery using resample seems a little complicated. Particularity when it comes to lining up and creating your ground polygons - I'd rather have everything contained in a single GMAX file that can all be editied at once.

I think resample is not complicated. It is easier to do than cutting 50 pictures as textures.
Making model in gmax to match photoscenery is possible now with MCX. Arno create Round World correction tool to manage that.

 

[JRobinson]

I agree that resampled PR is by far simpler than a gmax ground poly. IMHO the only reason a person would want to use imagery on the GP itself would be if you were lucky enough to find imagery that exceeded the 7cm resampled PR limit or if you were planning on synthesizing your own GP textures beyond that resolution. The latter is a royal pain in the a$$ from my experience but it can be done and does produce a nice crisp result.

Drawcalls are not a huge issue, I just did one at 2cm with 140 individual textures and users are reporting very good performance from the airport as a whole. There are almost 400 individual textures in the associated texture folder (including seasonal and night GP textures, hangar textures, etc.). I've been rather generous with the pixels throughout the entire project .

Granted this is a medium GA airport, I think it would probably be prohibitive on large intl airports if for no reason other than synthesizing the GP textures would make you stir-crazy.

Jim

 

[arno]

I prefer photo scenery as well. I feel it gives better performance in general and it is much easier to make. Aligning custom ground polygons exactly to the real world location is much more work than turning a geotiff into some photo scenery.

Of course for taxiways you need custom ground polygons, because even at 7 cm the resample is not clear enough or that.

 

[jtanabodee]

Drawcalls are not a huge issue, I just did one at 2cm with 140 individual textures and users are reporting very good performance from the airport as a whole. There are almost 400 individual textures in the associated texture folder (including seasonal and night GP textures, hangar textures, etc.). I've been rather generous with the pixels throughout the entire project .
Jim

Oh my! The texture at that amount could make my computer into a Powerpoint slide show.

I did once with only 40 ground polys. I found that it is quite a hit on frame rate. What is your project you mention? I'll go to buy that at simmarket and try.

I think it depends on the computer that user use as well. I have a plain decent one.
One of my friend bought an airport in Poland a year ago and he said he could not fly. Fps is un-flyable. However not so many people complaint that.

 

[JRobinson]

It's a lot more drawcalls than I'd prefer and I wouldn't want to make one any larger. The thing is you can barely tell the difference between 2cm and 4cm in terms of resolution because they mip to 512px while you're still very close, I'd say if you were in slew mode 50m above the ground you'd be looking at the 512px mip level however I haven't tested that.

I in fact did a couple remote areas of the GP at 4cm to save a few drawcalls, it's distinctly more blurry than the 2cm part but still looks quite good IMHO. I'm remapping the ground poly ATM (in between beers) to use 2048 texture sheets. My plan is to export them all at 1024 and then make an HD set of GP textures available at 2048px for those that don't mind keeping the TML tweak in their .cfg and still want to see a 2cm GP.

There's definitely a pause when the GP comes into view and you can watch the GP "fill in" as the textures load. It's all over in a blink though and then I don't really see where there's much of a performance hit at all. Most users of the scenery seem to be using pretty up to date hardware, SSDs, etc. I'm running an I7-2600K at 4.4 Ghz, 8Gb DDR 3, GTX-580 and everything runs off a couple of SSDs.

It's here BTW:
http://www.fullterrain.com/product_us65s.html

Jim

 

[hcornea]

By the looks of it, Tic, it is being developed by

Darren Seare (Aviasim) and Aaaron Graham (AWG)
So they might be able to answer the question as to the tech they have chosen.

Looking at the other pictures on the website it does indeed look like the phototerrain is being carried on the groundpoly, although it may simply be a template. If they are planning an FS9 version, this might be a reason for choosing this technique.
In FS9, this was the only way to get acceptable resolution because the terrain engine won;t do hi-res ground imagery, but in FSX with resample able to display down to 7cm/px and progressively and efficiently, resample is a viable and very efficient option.

A good resampled photoimage, underneath a Max-Gmax modelled taxi-apron-runway looks best to my eye. The progressive loading of runway surfaces is a bit of an immersion killer for me, and the photoreal is easy and quick (and can process massive areas)

 

[Southwest]

I don't like the look of it at all; there's a Moire pattern over them a little. Plus, The performance seems to take quite a hit. Seasons are hard to implement (though I think the ground poly wizard does them now). You need to cut up the image etc...

@Shaun -The Moire pattern you see (assuming you're refering to my project) is the result of a non-symmetrical concrete texture on the taxiway, i.e, there is a vertical line and difference in color. An effect that might/would be present in any scenery regardless of the aerial imagery design method.

Oh my! The texture at that amount could make my computer into a Powerpoint slide show.

I did once with only 40 ground polys. I found that it is quite a hit on frame rate. What is your project you mention? I'll go to buy that at simmarket and try.

I think it depends on the computer that user use as well. I have a plain decent one.
One of my friend bought an airport in Poland a year ago and he said he could not fly. Fps is un-flyable. However not so many people complaint that.

@Tic - I this morning took the opportunity to re-sample my aerial imagery, containing a watermask and blend mask.

Using the same setup; aircraft, scenery settings and location, I compiled each of the methods and whilst I concur that there is a performance hit, it was not significant enough for me to change my scenery design method neither has it any real impact.

The average frame rate was just 5fps higher with the re-sampled photo scenery, compared to the GMAX photo scenery - whilst some might complain it was a poor test, it seemed relatively fair and, whilst the clarity remained sharp with the GMAX polys, it left the re-sampled imagery a lot to be desired... Even at a 25-50cm photo.

I'm not the only developer to utilize this method, many of the larger design groups such as Aerosoft and UK2000 also employ this.

If it's not to some users tastes, it would be better for both parties if they didn't download my work... or work that used this technique.

 

[Shaun]

Southwest, the Moire pattern I was referring to was from the Aerosoft "holiday airports". Perhaps they didn't use mipmaps.

If it's not to some users tastes, it would be better for both parties if they didn't download my work... or work that used this technique.

That's one way of losing potential customers! I don't care whether a product uses this or not if it's good and the performance is good! The reason for discussing it is because we need to know the pros and cons and be able to decide whether we should implement it in our projects!

 

[Southwest]

Southwest, the Moire pattern I was referring to was from the Aerosoft "holiday airports". Perhaps they didn't use mipmaps.


That's one way of losing potential customers! I don't care whether a product uses this or not if it's good and the performance is good! The reason for discussing it is because we need to know the pros and cons and be able to decide whether we should implement it in our projects!

Sorry Shaun, jumped to conclusions. Long day.

 

[Maxman]

Interesting thread. never used the full poly method, but have thought about it. I get good results with the usual way, but will try this out and see if there are any benefits/drawbacks.

 

[jtanabodee]

Looking at the other pictures on the website it does indeed look like the phototerrain is being carried on the groundpoly, although it may simply be a template. If they are planning an FS9 version, this might be a reason for choosing this technique.

I could not agree more. It is the only way to do that and get two birds in one shot.

The average frame rate was just 5fps higher with the re-sampled photo scenery, compared to the GMAX photo scenery - whilst some might complain it was a poor test, it seemed relatively fair and, whilst the clarity remained sharp with the GMAX polys, it left the re-sampled imagery a lot to be desired... Even at a 25-50cm photo. If it's not to some users tastes, it would be better for both parties if they didn't download my work... or work that used this technique.

No, Southwest. I think your experiment is good enough. We would like to know that which technique is better, it does not mean that your ground poly technique is not good way to do at all!.

I think you can compare the process of making. I think you have to compare the length of the time of making ground poly at 50 separated textures to resample as well. Resample takes much less time to do, doesn't it?
Moreover, if you have white line between the texture, you have to fight with that more too.

But I have to admit that the picture from ground poly is clearer than photoscenery.

The reason for discussing it is because we need to know the pros and cons and be able to decide whether we should implement it in our projects

Very good conclusion of the main point of this thread. May be I was not so clear at the beginning of the discussion.

All the time in the past I always thought that why wasting time making ground poly, photoscenery capable of 7cm/pixel. Ground poly is a bad guy, photoscenery is a good guy for FSX. But there are some reasons behind to choose ground poly over photoscenery too. You have to choose between two methods.

I think I'm going to have conclusion here, waiting for more opinions.

 

[jtanabodee]

I think I have some conclusion for choosing satellite photo to be on ground poly or photoscenery.

Choose ground poly for satellite photo in case of:
1. You need two version, FS9 and FSX. You can have both versions in one shot.
2. You have satellite photo resolution beyond 7cm/pixel.
3. You have flat airport with no hills nearby. The terrain is perfectly flat.
4. You want the satellite photo to be crisp and clear as much as possible.
5. Your airport is small. You have less objects.
6. You are willing to do a lot of work by cutting satellite photo into pieces and apply each of them to the tiles of ground poly. It is time consuming and not easy. If you forget anything you might need to redo it. If you have white lines between tile you need some more processes.


Choose Phtoscenery for satellite photo in case of:
1. You have only FSX version.
2. You have average satellite photo resolution such as 60cm/pixel.
3. Your project is on international huge airport with a lot objects and buildings already consume a lot of texture sheets.
4. You hate doing ground poly by cutting a big photo into pieces and apply to the tiles.

I think I have a compromise method in my previous Suvarnabhumi Airport project.
I use average resolution of satellite photo for the whole airport. Where it needs a better resolution, I'll use ground poly over that place. So, I did save a lot of work by doing so.

 

[hcornea]

In addition to the above, there is not much 'good' imagery available that is above 15cm/px.

It is also hideously 'big' at that resolution.

 

[Aviasim]

The image you posted is a very early shot taken a few weeks ago, as of right now the entire ground polygon is being modeled in 3DS Max, I will explain why:

It is still early in development, we have not yet decided if we are going to do an FS9 version, so to save later issues, we have gone with this method for now so it will work and look the same in both FSX and FS9 if an FS9 version is agreed on.

Also, AFAIK, this airport will be released for most FS platforms, FS9, FSX, P3D, XP10, but again, we are not 100% sure which platforms it will be released for, so that gives me another good enough reason to stick with custom ground polys all created in 3DS Max as it's pretty much universal, many many different factors to consider for such a large widespread project.

Please do not assume everything I am saying to be true, I am just the person making it, it is Aerosoft that are making decisions such as what platform(s) it should be available for. Also, something I would like to make clear about this project...to put it simply, AWG's idea, contracted by Aerosoft, developed by myself alone.

Also another reason I have (so far) done the ground poly in 3ds max is because I dislike the finished look of FSX photoscenery, but as it has already been stated, both methods have their pros and cons and you can't please everybody but I would indeed go with what the community prefer, BUT (again, so many "buts") - if I did do FSX photoscenery via the resample tool, it wouldn't work for FS9, just FSX and P3D, not sure about XP10 but I doubt it, therefore I would have to make another version that works with FS9, and another version that works with XP10. So yes, a lot of things to consider but I will notify Aerosoft and AWG of this threads poll to help make a decision given by the community.

Regards

 

[jtanabodee]

Crystal clear sir, Aviasim.

As I already said, it is not about what is good and what is not. We just would like to find out what would be the decision making points. I just want to know the opinions about this, photoscenery vs ground poly.

You decision is very good, choosing Ground poly, since you are not sure if that it will be in FS9 version. Ground poly will give two versions in one shot.