Re: [Flightgear-devel] Aircraft modellers - is a grain texture useful?
Okay, I've pushed an experimental version of a grain overlay texture for the model ubershader to FGData. It affects Atmospheric Light Scattering only, i.e. will be absent in the default rendering, which should make for easy comparison. For lack of texture units, I had to take the rainbow coloring of reflections out for the moment (again, only in the Atmosperic Light Scattering version). I can't visually spot a difference, and in any case a 2d texture lookup call seems an overkill for a simple 1d color table, so I plan to replace that by a function eventually. As far as I can see and test, this shouldn't take any framerate unless used. The grain overlay is configured pretty much like any other model effect in the ubershader - a model specific effect file needs to set the flags, which are * grain-texture-enabled: does what you think it does, needs to be 1 to work * grain-magnification : the texture magnification relative to the base texture - I think values between 10 and 100 would work here The grain texture itself needs to be declared as n=14. The grain texture should be largely transparent and seamless - I think unlike for the terrain tiling artefacts are not an issue for artificial patterns, they actually occur. For a quick check, inserting the following xml code into Aircraft/Citation-Bravo/Models/Effects/reflect.eff texture n=14 imageTextures.high/Terrain/grain_texture.png/image filterlinear-mipmap-linear/filter wrap-srepeat/wrap-s wrap-trepeat/wrap-t internal-formatnormalized/internal-format /texture grain-texture-enabled1/grain-texture-enabled grain-magnification50/grain-magnification gives me this effect for the hull of the Bravo which is now re-painted using the terrain grain texture at high resolution http://users.jyu.fi/~trenk/pics/overlay.jpg Looks a bit like a military version... So, please play with it - it's basically down to how well the grain overlay can be made. * Thorsten -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Aircraft modellers - is a grain texture useful?
Thorsten Okay, I've pushed an experimental version of a grain overlay texture for the model ubershader to FGData. It affects Atmospheric Light Scattering only, i.e. will be absent in the default rendering, which should make for easy comparison. For lack of texture units, I had to take the rainbow coloring of reflections out for the moment (again, only in the Atmosperic Light Scattering version). I can't visually spot a difference, and in any case a 2d texture lookup call seems an overkill for a simple 1d color table, so I plan to replace that by a function eventually. As far as I can see and test, this shouldn't take any framerate unless used. The grain overlay is configured pretty much like any other model effect in the ubershader - a model specific effect file needs to set the flags, which are * grain-texture-enabled: does what you think it does, needs to be 1 to work * grain-magnification : the texture magnification relative to the base texture - I think values between 10 and 100 would work here The grain texture itself needs to be declared as n=14. The grain texture should be largely transparent and seamless - I think unlike for the terrain tiling artefacts are not an issue for artificial patterns, they actually occur. For a quick check, inserting the following xml code into Aircraft/Citation- Bravo/Models/Effects/reflect.eff texture n=14 imageTextures.high/Terrain/grain_texture.png/image filterlinear-mipmap-linear/filter wrap-srepeat/wrap-s wrap-trepeat/wrap-t internal-formatnormalized/internal-format /texture grain-texture-enabled1/grain-texture-enabled grain-magnification50/grain-magnification gives me this effect for the hull of the Bravo which is now re-painted using the terrain grain texture at high resolution http://users.jyu.fi/~trenk/pics/overlay.jpg Looks a bit like a military version... So, please play with it - it's basically down to how well the grain overlay can be made. Removing the rainbow effect spoils the highly polished aluminium effect on the b29 and the Lightning F1. It is also incompatible with AO effects. Will this all work with non-nVidia cards/drivers? The grain effect you proposed did not gain much if any support from developers. Do we need to go down this road? We are breaking more and more for minimal gains. Did we ever restore the wake effect on the Carrier with Atmospheric Light Scattering? I think something like the grain effect can already be achieved with the nmap tiling facility in the existing ubershader. Vivian -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Aircraft modellers - is a grain texture useful?
I think that a better approach would be to allow multiple UV layers and textures (and texture modes, like decals) on the model format. I understand that right now FGFS only relies on the native AC3D loader, though AC3D is not the only 3D format supported by OSG by any means. But there's no reason why alternate lists of UV coordinates and textures could not be supplied along with the basic mesh. The cleanest implementation would use a FGFS native model format, but there's plenty of possible solutions, like a list of vertex indexes along with the corresponding UV coordinates and material definition to integrate the basic AC3D mesh, or several copies of the mesh with matching geometry and differing materials... I suspect that OSG is not being used to its full potential. Alessandro From: vivian.mea...@lineone.net To: flightgear-devel@lists.sourceforge.net Date: Mon, 22 Apr 2013 13:34:36 +0100 Subject: Re: [Flightgear-devel] Aircraft modellers - is a grain texture useful? Thorsten Okay, I've pushed an experimental version of a grain overlay texture for the model ubershader to FGData. It affects Atmospheric Light Scattering only, i.e. will be absent in the default rendering, which should make for easy comparison. For lack of texture units, I had to take the rainbow coloring of reflections out for the moment (again, only in the Atmosperic Light Scattering version). I can't visually spot a difference, and in any case a 2d texture lookup call seems an overkill for a simple 1d color table, so I plan to replace that by a function eventually. As far as I can see and test, this shouldn't take any framerate unless used. The grain overlay is configured pretty much like any other model effect in the ubershader - a model specific effect file needs to set the flags, which are * grain-texture-enabled: does what you think it does, needs to be 1 to work * grain-magnification : the texture magnification relative to the base texture - I think values between 10 and 100 would work here The grain texture itself needs to be declared as n=14. The grain texture should be largely transparent and seamless - I think unlike for the terrain tiling artefacts are not an issue for artificial patterns, they actually occur. For a quick check, inserting the following xml code into Aircraft/Citation- Bravo/Models/Effects/reflect.eff texture n=14 imageTextures.high/Terrain/grain_texture.png/image filterlinear-mipmap-linear/filter wrap-srepeat/wrap-s wrap-trepeat/wrap-t internal-formatnormalized/internal-format /texture grain-texture-enabled1/grain-texture-enabled grain-magnification50/grain-magnification gives me this effect for the hull of the Bravo which is now re-painted using the terrain grain texture at high resolution http://users.jyu.fi/~trenk/pics/overlay.jpg Looks a bit like a military version... So, please play with it - it's basically down to how well the grain overlay can be made. Removing the rainbow effect spoils the highly polished aluminium effect on the b29 and the Lightning F1. It is also incompatible with AO effects. Will this all work with non-nVidia cards/drivers? The grain effect you proposed did not gain much if any support from developers. Do we need to go down this road? We are breaking more and more for minimal gains. Did we ever restore the wake effect on the Carrier with Atmospheric Light Scattering? I think something like the grain effect can already be achieved with the nmap tiling facility in the existing ubershader. Vivian -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Aircraft modellers - is a grain texture useful?
Removing the rainbow effect spoils the highly polished aluminium effect on the b29 and the Lightning F1. As I said, I don't plan to remove it for good. Quoting myself: in any case a 2d texture lookup call seems an overkill for a simple 1d color table, so I plan to replace that by a function eventually I might add 'this will make it quite a bit faster, as it is a very simple function' - so I believe this should be done anyway everywhere the rainbow is used. I am working hard, but don't expect everything to be 100% on the first commit of a new feature. It is also incompatible with AO effects. Will this all work with non-nVidia cards/drivers? I believe I've seen screenshots of terrain overlay textures working just fine on ATI cards. Likewise, functions rather than texture lookups work just fine - what counts in the end is a number, the shader doesn't really care if this is calculated or read from texture. The four websites I have studied regarding conditional texture lookups agree that textures can be looked up conditionally on a uniform, not on a varying. Do you see actual reasons for concern, or is this just stabbing in the dark? Not sure why a grain overlay would be incompatible with AO - care to elaborate? My understanding is that we don't have any AO outside of Rembrandt, and a grain would not be intended to carry pre-computed shadows, that's what the base texture is for. The grain effect you proposed did not gain much if any support from developers. Do we need to go down this road? No, we don't have to. Like many things, overlay textures and the grain effect are just something I believe have incredible potential. The grain effect on terrain is awesome - without going dds or using huge textures, you can create 15 cm sized terrain resolution everywhere. So, let's give it a few months of testing, see if folks can not use it to good effect - the 5 lines are easily removed from the shader if the potential doesn't materialize. We are breaking more and more for minimal gains. I beg to disagree on two counts. First of all, this is a net acceleration. I think currently the ubershader isn't structured well since it unconditionally looks up lots of textures, most of which aren't needed if you use, say, reflection or normal map only - restructuring the shader to not read unused textures and to evaluate as function what can be evaluated as simple function will speed things up. Second, having a technique to achieve 25 times the resolution for 2 times the texture memory isn't a minimal gain. It's visually way more powerful than the rainbow. So we're actually getting more bang for the buck. Did we ever restore the wake effect on the Carrier with Atmospheric Light Scattering? Well, we never had it running in the first place, so there can be no talk about restoring it. Someone just has to write it. Presumably that someone will eventually be me, but I have to ask your forgiveness of I priorize things which interest me personally. I mean, it's not like there's something taken away from you... There's two rendering frameworks left in which everything works as you're used to, surely we can afford to have one of three going ahead and trying for a few experimental new features rather than re-doing every effect in the others? Cheers, * Thorsten -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Aircraft modellers - is a grain texture useful?
Ive been thinking about this since since you posted, and now i'm curious to see it.My initial fear was more framerate drop, but if it can be truly disabled I think its worth a try I think one thing we have pretty consistently implemented in the effect framework is that all effects can be switched off. The whole model ubershader is implemented in such a way that it affects you only if you have a model shader on. The grain texture can be implemented such that it affects you only if you have the model shader on at high quality and your model has a flag set such that it is used. Water reflection used to have nearly zero impact on my framerate , now its unuseable over the ocean or large lake. Which one? We used to have two of them, a silvery one at lower quality and the sine wave variant at high quality. Even the high quality variant can be made to run almost twice as fast by dropping half the partial wave calculations (this is implemented in the lower quality version of Atmospheric Light Scattering). I haven't been following the shaders in the default framework so much, but if a shader suddenly eats up twice the performance, there usually is a reason worth understanding. Not sure why but the skydome shader had very little effect on my framerate when it first appeared , now it drops fps to 10 from 40 . Well this at least I know. When the skydome shader first appeared, it did this when you didn't have mountains on the horizon: http://www.phy.duke.edu/~trenk/pics/skydome1.jpg Your framerate has gone into fixing this problem by providing consistent fogging and lighting of the terrain under all conditions such that terrain matches with the skydome. And unfortunately, the terrain part is way more expensive than the skydome part (and if you run at higher quality, there's a gazillion of additional goodies). The skydome code itself is pretty much as fast as it used to be (and if you delete all skydome-switched techniques from terrain-default.eff and model-default.eff, you can get if back if you really like). * Thorsten -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Aircraft modellers - is a grain texture useful?
On Wed, 17 Apr 2013 06:35:19 + Renk Thorsten wrote: But okay, I asked for feedback and I got it - point taken, feature not considered interesting from the modeller side. My modelling activity is in extended limbo at the moment so I was reluctant to comment, but the lack of texturing on cockpit walls etc has always been something that jarred with me... on the Bocian (and Camel, come to think of it) I tried to ensure that every surface in the cockpit was textured. This was OK on a tiny aircraft like a glider, but on something bigger and more complex I think the shader idea has something going for it, for cockpit walls etc which are not modelled in the same detail as the individual panels alongside them - certainly well worth experimenting with I'd say. AJ -- -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Aircraft modellers - is a grain texture useful?
Ive been thinking about this since since you posted, and now i'm curious to see it.My initial fear was more framerate drop, but if it can be truly disabled I think its worth a try.Currently I can disable shaders and get decent performance , 30-40 fps , which makes a flight doable.I do keep trees on , with minimal impact if I keep the slider at 1.0 or less.Water reflection used to have nearly zero impact on my framerate , now its unuseable over the ocean or large lake.Not sure why but the skydome shader had very little effect on my framerate when it first appeared , now it drops fps to 10 from 40 . So I cringe every time someone mentions a fix,;). Syd On Thu, Apr 18, 2013 at 5:03 AM, AJ MacLeod aj-li...@adeptopensource.co.ukwrote: On Wed, 17 Apr 2013 06:35:19 + Renk Thorsten wrote: But okay, I asked for feedback and I got it - point taken, feature not considered interesting from the modeller side. My modelling activity is in extended limbo at the moment so I was reluctant to comment, but the lack of texturing on cockpit walls etc has always been something that jarred with me... on the Bocian (and Camel, come to think of it) I tried to ensure that every surface in the cockpit was textured. This was OK on a tiny aircraft like a glider, but on something bigger and more complex I think the shader idea has something going for it, for cockpit walls etc which are not modelled in the same detail as the individual panels alongside them - certainly well worth experimenting with I'd say. AJ -- -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Aircraft modellers - is a grain texture useful?
I'd say no , its easy enough to do without yet another shader, since each new shader 'improvement has me tweaking my aircraft to get back the frame rates I lost.But thanks for offering. Well, according to GLSL specifications and my experiments, texture lookups cannot be made conditional on a varying, but they can be conditional on a uniform integer. Which means that this can be implemented optionally without any performance overhead if the feature is not needed (that's not how the model ubershaders currently are written, they read textures regardless of the config flags, so I suspect they run slower on low quality levels than they really have to. I have been given to understand that this is because of Mac/ATI driver issues, but my medium quality terrain shaders read textures conditional on uniform int flags, and for me this gave a performance gain - seems to run fine on Mac and ATI as well, so it doesn't seem to be a nVIDIA exploit). I would follow the same opinion as Syd. I think Gimp/Inskape/Photoshop... are enough powerful to create correct texture. Well gimp is nice, but: Using 8192x8192 textures, with a 2x2 m cockpit size to texture, you get 0.25 mm resolution and have a 128 MB texture file. Using a 1024x1024 texture with a 256x256 overlay, you get pretty much the same resolution with 2 MB worth of textures. using a 1024x1025 overlay, you still have 4 MB textures only and can create 4 times the resolution. So there's that. The fact of the matter is that very few aircraft are textured in high quality (even a really good aircraft like the b1900d has lots of monochromatic surfaces on the panel) and if we had a library of a few overlay pattern, it would not require a photoshop artist but just a few lines of xml to fix that for good. The fact of the matter is also that once I turn my head and look away from the panel, the texture resolution in pretty much all aircraft decreases dramatically. But okay, I asked for feedback and I got it - point taken, feature not considered interesting from the modeller side. * Thorsten -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Aircraft modellers - is a grain texture useful?
Am Tue, 16 Apr 2013 06:34:26 + schrieb Renk Thorsten thorsten.i.r...@jyu.fi: I have a question to aircraft/cockpit modellers: Would a shader effect with the equivalent of a grain texture be useful to you? For the terrain, the grain texture is a semi-transparent overlay pattern of grainy dots - which is superimposed on the normal texture at 25 times the nominal resolution (so while a usual pixel on the terrain might be 4x4 m sized, a pixel of the grain pattern is 16cm x 16 cm. This gives the appearance of a texture resolution which is much higher than it actually is: http://www.flightgear.org/forums/viewtopic.php?f=47t=18628#p173410 In cockpits, I often see many monochromatic surfaces. When I look at the panel of my card, the plastic is monochromatic but has a fake leather pattern imprinted. The roof of my car has a cloth structure. My computer has some rhombus pattern imprinted. Metal surfaces often have some brush stroke structure. All these things are literally screaming for an overlay texture, as they are artificial repeating patterns and there is in fact no tiling problem as in terrain shading - they can just be superimposed, creating sub-millimeter-sized resolution on cockpit details at the expense of a single texture lookup. Now, I would offer to code a slot for a grain texture into the high-quality model shader of Atmospheric Light Scattering, but since I am not a 3d modeller and I suspect there are some issues with the uv-mapping which are a bit different from the way terrain works, I would need someone from the model side who is interested in exploring this idea. Let me know if anyone is interested. I like the idea. It is always a problem to get the Cockpit looking right. Using a high res texture gives a lot of details, but requires a lot of work and resources. Seamless textures save a lot of texture memory and improves the look of the wide areas a lot, but denies any use of e.g Ambient Occlusion. AO gives a somehow grainy appearence which looks ok, but with large interiours (e.g Transports, Bombers) it requires huge texture sizes to look good. I guess using a Shader for interiour will improve the overall look (I already use the model shader for interiour and it definitly improves the look and feel). Since I'm currently working on improving the Sabre Cockpit I would be ready to try some things out. Greetings * Thorsten -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Aircraft modellers - is a grain texture useful?
I'd say no , its easy enough to do without yet another shader, since each new shader 'improvement has me tweaking my aircraft to get back the frame rates I lost.But thanks for offering. Syd On Tue, Apr 16, 2013 at 12:34 AM, Renk Thorsten thorsten.i.r...@jyu.fiwrote: I have a question to aircraft/cockpit modellers: Would a shader effect with the equivalent of a grain texture be useful to you? For the terrain, the grain texture is a semi-transparent overlay pattern of grainy dots - which is superimposed on the normal texture at 25 times the nominal resolution (so while a usual pixel on the terrain might be 4x4 m sized, a pixel of the grain pattern is 16cm x 16 cm. This gives the appearance of a texture resolution which is much higher than it actually is: http://www.flightgear.org/forums/viewtopic.php?f=47t=18628#p173410 In cockpits, I often see many monochromatic surfaces. When I look at the panel of my card, the plastic is monochromatic but has a fake leather pattern imprinted. The roof of my car has a cloth structure. My computer has some rhombus pattern imprinted. Metal surfaces often have some brush stroke structure. All these things are literally screaming for an overlay texture, as they are artificial repeating patterns and there is in fact no tiling problem as in terrain shading - they can just be superimposed, creating sub-millimeter-sized resolution on cockpit details at the expense of a single texture lookup. Now, I would offer to code a slot for a grain texture into the high-quality model shader of Atmospheric Light Scattering, but since I am not a 3d modeller and I suspect there are some issues with the uv-mapping which are a bit different from the way terrain works, I would need someone from the model side who is interested in exploring this idea. Let me know if anyone is interested. * Thorsten -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Aircraft modellers - is a grain texture useful?
Hi Thorsten, I would follow the same opinion as Syd. I think Gimp/Inskape/Photoshop... are enough powerful to create correct texture. Of course it requires some time of work... But isn't it expected to spend some of our time in order to have a beautiful aircraft ? :) Thanks you for proposing ! Cheers, Clément -- Precog is a next-generation analytics platform capable of advanced analytics on semi-structured data. The platform includes APIs for building apps and a phenomenal toolset for data science. Developers can use our toolset for easy data analysis visualization. Get a free account! http://www2.precog.com/precogplatform/slashdotnewsletter___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel