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OSGearth as default scenery?

osgEarth renders the terrain scene by building the textured geometry at runtime from raw source imagery and elevation data. An experimental FlightGear integration is currently available.

Re: OSGearth as default scenery?

Postby Richard » Sun Apr 10, 2016 9:25 pm

The fundamental problem with osgEarth that hasn't been addressed is the integration with our shaders; and osgEarth needs shaders particularly for the logarithmic z-buffer.

Also when people think of osgEarth it's wrongly thought of (IMO) as providing satellite imagery, that's not really what osgEarth is about - osgEarth is a geospatial and terrain engine; that can take data a number of standards based formats (it uses GDAL). TerraGear could theoretically be modified to create an osgEarth compatible dataset

- It doesn't require to the data to be streamed, it will equally well work with local data
- In my tests because of the LOD management it places a slightly lower load on the graphics cards.

Satellite imagery generally looks good from one angle, but when I tried flying about with the osgEarth build I actually found that it was terrible over urban areas, but quite good in the mountains and over the countryside.

To quote poweroftwo's notes
Compromises – known limitations of initial implementation

* Only a single material / landclass – (runway) is used in this implementation.
* Typical ground texture resolution is lacking compared to the native FlightGear geo typical runways and taxiways.
** Micro-texture (a.k.a. detail texture) could be utilized to improve effective ground texture resolution
* KML loading / rendering issues
** FlightGear render non-textured models poorly
** Currently all KML found in the path are loaded regardless of their ground texture resolution. distance from the ownship’s position. To improve load performance, some type of spatially organized framework along with use of the OSG paging mechanism such as proxy nodes should be implemented.
** During initial load of a textured model, some runtime visual artifacts are produced due to OpenGL graphics conflicts. Quitting FlightGear and rerunning restores the correct state.
* Fog - works with Rembrandt, but does not otherwise
* 3D clouds – The Up vector gets out of kilter over long distances
* Need to load height fields that are nearby and page out others.
* No airport lighting in this implementation.


What I read into Jeff's notes is that there is actually a lot of work to do before osgEarth could be a complete replacement for the current terrain engine. There has been a fair amount of criticism of the current WS2.0 floating about recently - but without anyone actually saying how good the current terrain is. There are problem areas, but overall the terrain is excellent and can be further improved by texturing and adding appropriate shader use.
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Re: OSGearth as default scenery?

Postby Hooray » Sun Apr 10, 2016 9:45 pm

I agree, but to be fair, there are other features, committed ones, that are nowhere near "primetime" quality (think Rembrandt) or ones that are simply impossible to integrate sufficiently with existing features because they are mutually exclusive (see above),

I don't think poweroftwo ever suggested that his work is supposed to be a feature-complete replacement, it was posted as an experimental set of patches to promote photscenery using a 3rd party library/framework (osgEarth), so if anything it was posted as a prototype to become the foundation for an alternate scenery engine based on photoscenery, fully aware of its restrictions and the limitations that photoscenery as a whole brings.

But I can confirm your comments regarding the performance overhead of osgEarth - in fact, my original posting after testing the default scenery performance footprint against osgEarth was this:

Initial FlightGear / OsgEarth integration
Hooray wrote: Just testing LOWI for the first time (without any scenery installed besides the default scenery!), so far it's been taking about 2 minutes and scenery is starting to look plausible now - there was noticeable lag during the first 45 seconds (some frames taking 1-2 seconds then), and after 3 minutes it's simply starting to look awesome - but frame rate is suddenly down to ~40 fps here and frame latency is also about 45ms now, but that's with advanced weather running ...

Image


(note that there is another posting pre-dating bschack's WS 2.0 related findings where he identified too many/redundant triangles as being the culprit)
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Re: OSGearth as default scenery?

Postby Thorsten » Mon Apr 11, 2016 5:13 am

Whenever competing/conflicting features are brought up for review, people tend to forget that the freedom of choice is one of the key principles in open source, and particularly in FlightGear, e.g. quoting Torsten


Sorry - why is it you're continuing to argue? And what are you arguing for?

Curt wrote: No one is opposed to adding support for osgEarth as long as it doesn't subtract from anything else.

I wrote: I don't think anyone is fundamentally opposed to that (at least not that I'm aware of) - but someone needs to provide the patch and it has to be reviewed.

Etc....

So the holdup is not that anyone would want to restrict anyone's freedom here, or that there would be massive opposition against an optional feature - the holdup is that someone actually has to do it, provide a patch /patches in a form that can be reviewed, takes feedback into account,...

Trying to convince the people who have already decided they're not that much interested in having it by freedom of choice arguments is probably futile, because freedom of choice for me means I have the freedom not to be interested in photo scenery.


- In my tests because of the LOD management it places a slightly lower load on the graphics cards.


Not sure what the comparison standard is, but I can't recall having ever seen a low-light screenshot of OSGEarth, so I assume also the lighting and fogging computations done are fairly simple, which might also explain the performance difference.
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Re: OSGearth as default scenery?

Postby hamzaalloush » Mon Apr 11, 2016 7:36 am

do you recognize that proffessional FTD simulators don't even have proper scenery? our's are much better visual wise, but they don't need that as their main concern is less frame times, an airport, and terrain data...

for Flight Training purposes all this visuals amount to nothing, i vote for a photo scenery launch option, i don't even understand the developer community rejecting it, if we'd have a simulator for real training purposes, i guess we should resurrect this topic in the dev list with these points attached, i'm pretty sure some of them have flown in these simulators.
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Re: OSGearth as default scenery?

Postby Thorsten » Mon Apr 11, 2016 7:42 am

i vote for a photo scenery launch option, i don't even understand the developer community rejecting it


1) It's not up for vote (few things ever are)
2) It's been said a couple of times now that nobody is rejecting it
3) Feel free to run FG without scenery - or with a simplified scenery - of whatever terrain mesh you like (the Red Bull Air Race just uses FG with a 3d model of the race course)
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Re: OSGearth as default scenery?

Postby hamzaalloush » Mon Apr 11, 2016 7:45 am

ok so "i vote" some other than me be the messenger for this, because what other credits in my name that could cause the devs to consider this?

i know some things which i will not discuss here, but i'v info on these training devices, and have an idea what their priorities are.

edit: (after your edited comment), i need photoscenery.
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Re: OSGearth as default scenery?

Postby Thorsten » Mon Apr 11, 2016 9:01 am

Why are you pretending that 'no one is considering photoscenery' and the problem is to get people to consider it? People have considered it and have decided to focus on other priorities because they're not sufficiently interested.

To repeat: The problem is not

* any sort of conspiracy that people actively reject photoscenery
* that people would be unaware of the option
* that nobody has ever requested an implementation

The problem however is

* finding someone else who is interested, has the ability to code it and is willing to account for feedback for a patch

Maybe if you could focus on solving the actual holdup, instead of trying to address things which simply aren't the problem? It'd really increase the chance of anything happening tremendously.
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Re: OSGearth as default scenery?

Postby hamzaalloush » Mon Apr 11, 2016 10:33 am

for starters i can easily compile ready made Flightgear with photoscenery feature enabled for Windows, but that would be FG-3.2,3.4

can you help me encourage the dev community to port this over?

not much i can do more that that.

i admire your clearing about the historical relevance about this subject, but i appreciate no downplaying(as from your tone i get, or probably misunderstanding), but you're a pretty smart guy.
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Re: OSGearth as default scenery?

Postby Hooray » Mon Apr 11, 2016 10:42 am

As has been said, providing osgEarth as an optioin will involve several steps, at the very least:
  • being able to build sg/fg from source
  • add the gitlab branches as remote tracking branches
  • check out the branches, rebuild & test
  • try to rebase onto sg/fg and fgdata
  • clean up what's broken (compiler errors)
  • push everything to a set of branches so that others can help review/test the whole thing
  • put up a merge request and incorporate any feedback
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Re: OSGearth as default scenery?

Postby jaxsin » Mon Apr 11, 2016 11:17 am

There has been a fair amount of criticism of the current WS2.0 floating about recently - but without anyone actually saying how good the current terrain is.


It's hard, while I appreciate the efforts, to say the scenery is 'good' would be an overstatement. Now this is strictly coming from my own perspective, clearly I am the only one who cares to fly where I do.

What makes this even worse is the lack of the map server to feasibly generate new scenery (WIP). Again, it's the stagnation that is killing scenery at the moment. Not the implementation afaic.
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Re: OSGearth as default scenery?

Postby Thorsten » Mon Apr 11, 2016 12:20 pm

Again, it's the stagnation that is killing scenery at the moment.


May I ask what your background and involvement in the scenery generation process is?

(You sort of joined this forum Dec 2015 and see stagnation after a few months already?)

can you help me encourage the dev community to port this over?


In case that was directed to me - are you really asking me whether I can help you convince people who have decided something is not worth their time to do it anyway while I am also convinced it's neither worth my nor their time? No, I really can't do that with a straight face.
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Re: OSGearth as default scenery?

Postby PINTO » Mon Apr 11, 2016 4:22 pm

It's really not that hard to see the stagnation. Takeoff from KSFO, head ~3nm west, and see how broken the scenery is. Repeat in a month. If it wasn't stagnate, then this would've been fixed a while ago.

And, yeah, the scenery is nice. Usually. But when I can't land at 10%-20% of all airports, including airports in the SF Bay area, because of scenery problems, it leaves a bad taste in my mouth. When there are random cliffs and entire islands in the wrong place and the coast is all messed up, it leaves a bad taste in my mouth.
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Re: OSGearth as default scenery?

Postby jaxsin » Mon Apr 11, 2016 4:27 pm

Thorsten wrote in Mon Apr 11, 2016 12:20 pm:
Again, it's the stagnation that is killing scenery at the moment.


May I ask what your background and involvement in the scenery generation process is?



Sure you can ask, I will have zero issues telling you not much. But you surely already knew that, so on to your next point?

While I will stand by and accept your pov, you can't just discredit mine so easily. I have already made reference to my issues with the scenery, in a thread you were privy to. I have been in contact to see what can be done. I was told wait because things will improve. Otherwise I am ready and willing to move forward. Let me just put your fears to bed, I don't mind doing the leg work when I can.
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Re: OSGearth as default scenery?

Postby Thorsten » Mon Apr 11, 2016 5:02 pm

It's really not that hard to see the stagnation. Takeoff from KSFO, head ~3nm west, and see how broken the scenery is. Repeat in a month. If it wasn't stagnate, then this would've been fixed a while ago.


Then I guess scenery has always been stagnate, because it was a few years between world scenery versions 1.0 and 2.0 - compiling the whole world into scenery just has had a long release cycle for as long as I know FG.

You seem to be assuming there's be an easy way to 'just' fix the scenery world-wide, but I suspect in truth large parts of the 2.0 scenery haven't even been seen by any pilot yet. The world is a pretty large place... It's automated geodata processing for you - it gets 99.9% of cases right, but the 0.1% are found sooner or later and then everyone goes 'how could this possibly happen'.

In truth, I much prefer people spending their time on improving the toolchain than trying to manually fix the last 0.1%. Manual fixes don't scale - you'll be busy the next decade doing them and not be ready, an improved toolchain will get there much faster, even if it takes a few years from now till it's ready.

Understanding even just a fraction of the work that goes into scenery, I really appreciate the tremendous achievement that is the 2.0 scenery, and the degree to which these efforts continue to be bad-mouthed upsets me - more so since there's so little understanding just how futile manual approaches are in the face of the size of the planet.
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Re: OSGearth as default scenery?

Postby PINTO » Mon Apr 11, 2016 5:13 pm

Thorsten wrote in Mon Apr 11, 2016 5:02 pm:You seem to be assuming there's be an easy way to 'just' fix the scenery world-wide,

And you're assuming that I'm assuming. I'm not. But thanks for that. Whatever floats your boat.
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