Re: [Flightgear-devel] Object distance fading color
I've just pulled the new version and had a look and... it looks *very* impressive - with just a few property edits, one can generate a dark, overcast scene from a summer sky, and the diffuse haze comes out very nicely. Come to think of it, this might not be exactly what you're looking for but it could be useful to render overcast without an extreme amount of cloud vertices. Need to dig deeper to only affect the zenith of the skydome since that's handled elsewhere. After having a look, I realized something which I had not appreciated before, which is that as it is done now, it fixes a different problem: Currently, if we have overcast layers with good view underneath, the layer edge is always visible, i.e. there's blue sky at the horizon. The overcast property actually closes the horizon gap, i.e. in combination with a 3d layer drawn out to 55 km, the effect may be much better than what we have now. I have to write some code to set the amount of overcast as a function of altitude and play with it to see if it really gets the impression of a diffuse layer which can be crossed or if it is in the end needed to touch zenith and horizon separately - but my first impression is that what you have created is really working well for what I need. Thanks! * Thorsten -- Simplify data backup and recovery for your virtual environment with vRanger. Installation's a snap, and flexible recovery options mean your data is safe, secure and there when you need it. Discover what all the cheering's about. Get your free trial download today. http://p.sf.net/sfu/quest-dev2dev2 ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Object distance fading color
On Fri, 2011-06-03 at 10:36 +0300, thorsten.i.renk jyu.fi wrote: I was toying with the idea to model diffuse high-altitude haze by coloring the skydome as a function of altitude, i.e. paint the zenith a bit more hazy without touching the horizon and remove that effect again as you get above the haze layer - I believe that might create a better impression of such diffuse layers than placing texture sheets into the scene. Code for this has now been pushed to GIT. There is now a new property /rendering/scene/overcast ranging from 0.0 (normal behavior) to 1.0 (complete overcast). Erik -- Simplify data backup and recovery for your virtual environment with vRanger. Installation's a snap, and flexible recovery options mean your data is safe, secure and there when you need it. Discover what all the cheering's about. Get your free trial download today. http://p.sf.net/sfu/quest-dev2dev2 ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Object distance fading color
On Sun, 2011-06-05 at 10:26 +0200, Erik Hofman wrote: On Fri, 2011-06-03 at 10:36 +0300, thorsten.i.renk jyu.fi wrote: I was toying with the idea to model diffuse high-altitude haze by coloring the skydome as a function of altitude, i.e. paint the zenith a bit more hazy without touching the horizon and remove that effect again as you get above the haze layer - I believe that might create a better impression of such diffuse layers than placing texture sheets into the scene. Code for this has now been pushed to GIT. There is now a new property /rendering/scene/overcast ranging from 0.0 (normal behavior) to 1.0 (complete overcast). Come to think of it, this might not be exactly what you're looking for but it could be useful to render overcast without an extreme amount of cloud vertices. Need to dig deeper to only affect the zenith of the skydome since that's handled elsewhere. Erik -- Simplify data backup and recovery for your virtual environment with vRanger. Installation's a snap, and flexible recovery options mean your data is safe, secure and there when you need it. Discover what all the cheering's about. Get your free trial download today. http://p.sf.net/sfu/quest-dev2dev2 ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Object distance fading color
On 05.06.2011 10:26, Erik Hofman wrote: There is now a new property /rendering/scene/overcast ranging from 0.0 (normal behavior) to 1.0 (complete overcast). Just wondering: we have /sim/rendering, which contains a long list of properties - including properties for clouds and precipitation. And we have /rendering which contains the scene/dome properties only. Is there a specific reasons these are separate? cheers, Thorsten -- Simplify data backup and recovery for your virtual environment with vRanger. Installation's a snap, and flexible recovery options mean your data is safe, secure and there when you need it. Discover what all the cheering's about. Get your free trial download today. http://p.sf.net/sfu/quest-dev2dev2 ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Object distance fading color
On Sun, 2011-06-05 at 14:34 +0200, ThorstenB wrote: On 05.06.2011 10:26, Erik Hofman wrote: There is now a new property /rendering/scene/overcast ranging from 0.0 (normal behavior) to 1.0 (complete overcast). Just wondering: we have /sim/rendering, which contains a long list of properties - including properties for clouds and precipitation. And we have /rendering which contains the scene/dome properties only. Is there a specific reasons these are separate? Not that I know of, but I was always under the impression that /sim/rendering was honored once at startup only. Erik -- Simplify data backup and recovery for your virtual environment with vRanger. Installation's a snap, and flexible recovery options mean your data is safe, secure and there when you need it. Discover what all the cheering's about. Get your free trial download today. http://p.sf.net/sfu/quest-dev2dev2 ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Object distance fading color
On Fri, 2011-06-03 at 10:36 +0300, thorsten.i.r...@jyu.fi wrote: I'll see what I can come up with this weekend. Thanks, much appreciated! I've pushed a code change to be able to control the amount of light scattering (or absorption) of the fog by adjusting the /rendering/scene/scattering property. A value of 1.0 is full scattering and a value of 0.0 is full absorption (unrealistic). The default is set to 0.8 now. This did however revealed a sun position and for brightness position mismatch that I've confirmed was already in the code before this change. I can't believe no one noticed the massive offset at dusk (for KSFO) before. On another note: I seem to remember you had another request for the weather system but I was too busy to remember it. Do you remember what that was? I was toying with the idea to model diffuse high-altitude haze by coloring the skydome as a function of altitude, i.e. paint the zenith a bit more hazy without touching the horizon and remove that effect again as you get above the haze layer - I believe that might create a better impression of such diffuse layers than placing texture sheets into the scene. Ah yes, that was it, need to take another look at that then. Erik -- Simplify data backup and recovery for your virtual environment with vRanger. Installation's a snap, and flexible recovery options mean your data is safe, secure and there when you need it. Discover what all the cheering's about. Get your free trial download today. http://p.sf.net/sfu/quest-dev2dev2 ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Object distance fading color
I've pushed a code change to be able to control the amount of light scattering (or absorption) of the fog by adjusting the /rendering/scene/scattering property. A value of 1.0 is full scattering and a value of 0.0 is full absorption (unrealistic). The default is set to 0.8 now. Erik, prop-tie(/environment/relative-humidity,SGRawValuePointerfloat(_humidity)); is probably not a good idea since the FGEnvironment ties to this property, too (and it's the system that owns aka calculates this property. You should use getNode() and getDoubleValue() instead. Torsten -- Simplify data backup and recovery for your virtual environment with vRanger. Installation's a snap, and flexible recovery options mean your data is safe, secure and there when you need it. Discover what all the cheering's about. Get your free trial download today. http://p.sf.net/sfu/quest-dev2dev2 ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Object distance fading color
On Sat, 2011-06-04 at 15:03 +0200, Torsten Dreyer wrote: prop-tie(/environment/relative-humidity,SGRawValuePointerfloat(_humidity)); is probably not a good idea since the FGEnvironment ties to this property, too (and it's the system that owns aka calculates this property. You should use getNode() and getDoubleValue() instead. You're probably right, I didn't think of that. This part is reverted now. Thanks. Erik -- Simplify data backup and recovery for your virtual environment with vRanger. Installation's a snap, and flexible recovery options mean your data is safe, secure and there when you need it. Discover what all the cheering's about. Get your free trial download today. http://p.sf.net/sfu/quest-dev2dev2 ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Object distance fading color
I'll see what I can come up with this weekend. Thanks, much appreciated! On another note: I seem to remember you had another request for the weather system but I was too busy to remember it. Do you remember what that was? I was toying with the idea to model diffuse high-altitude haze by coloring the skydome as a function of altitude, i.e. paint the zenith a bit more hazy without touching the horizon and remove that effect again as you get above the haze layer - I believe that might create a better impression of such diffuse layers than placing texture sheets into the scene. Cheers, * Thorsten -- Simplify data backup and recovery for your virtual environment with vRanger. Installation's a snap, and flexible recovery options mean your data is safe, secure and there when you need it. Discover what all the cheering's about. Get your free trial download today. http://p.sf.net/sfu/quest-dev2dev2 ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Object distance fading color
Part of the problem is that FlightGear almost always renders ideal situations for the skydome. If you look at this picture you see there are situations where white fog is natural: http://upload.wikimedia.org/wikipedia/commons/2/2a/St.Gilgen_Panorama_2007-02-22.jpg But you obviously won't get that with the sun hidden behind a cloudy sky. Yes, that was my analysis as well. My point is - the skydome or terrain shader code can't know a priori. But all our weather systems have the relevant information readily available - all we need to do is expose a property which tells the distance fading code how much sunlight is available at a given altitude (below a layer, mountains should fade to dark, above to white for instance). * Thorsten -- Simplify data backup and recovery for your virtual environment with vRanger. Installation's a snap, and flexible recovery options mean your data is safe, secure and there when you need it. Data protection magic? Nope - It's vRanger. Get your free trial download today. http://p.sf.net/sfu/quest-sfdev2dev ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Object distance fading color
On Thu, 2011-06-02 at 12:53 +0300, thorsten.i.r...@jyu.fi wrote: Yes, that was my analysis as well. My point is - the skydome or terrain shader code can't know a priori. But all our weather systems have the relevant information readily available - all we need to do is expose a property which tells the distance fading code how much sunlight is available at a given altitude (below a layer, mountains should fade to dark, above to white for instance). I'll see what I can come up with this weekend. On another note: I seem to remember you had another request for the weather system but I was too busy to remember it. Do you remember what that was? Erik -- Simplify data backup and recovery for your virtual environment with vRanger. Installation's a snap, and flexible recovery options mean your data is safe, secure and there when you need it. Data protection magic? Nope - It's vRanger. Get your free trial download today. http://p.sf.net/sfu/quest-sfdev2dev ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
[Flightgear-devel] Object distance fading color
I've recently done a visual comparison between hires Flightgear scenery and reality - for those interested, see here: http://www.flightgear.org/forums/viewtopic.php?f=5t=12259 One of the striking points is that in reality even in partially clouded skies distant objects do not start to fade into white (as the Flightgear terrain shader assumes) but into darker colors, sometimes providing a striking contrast with the horizon sky color before they fade into the horizon color at even larger distance. I've played a bit with /rendering/scene/saturation to see if there was a way to recover that, but it didn't seem to do the right thing. I believe the relevant parameter is the amount of light reaching the surface at a given altitude. Naturally, the terrain shader can't know that up front, but the weather system has all the the information needed. If anyone is interested in attacking that problem from the shader side by exposing a property which can dial the 'darkness' of distant objects when they start to lose their color, I'd be happy to do my part from the weather side and cook up a model which sets the parameter value dependent on conditions. * Thorsten -- Simplify data backup and recovery for your virtual environment with vRanger. Installation's a snap, and flexible recovery options mean your data is safe, secure and there when you need it. Data protection magic? Nope - It's vRanger. Get your free trial download today. http://p.sf.net/sfu/quest-sfdev2dev ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Object distance fading color
On Wed, 2011-06-01 at 14:50 +0300, thorsten.i.r...@jyu.fi wrote: I've recently done a visual comparison between hires Flightgear scenery and reality - for those interested, see here: http://www.flightgear.org/forums/viewtopic.php?f=5t=12259 One of the striking points is that in reality even in partially clouded skies distant objects do not start to fade into white (as the Flightgear terrain shader assumes) but into darker colors, sometimes providing a striking contrast with the horizon sky color before they fade into the horizon color at even larger distance. I've played a bit with /rendering/scene/saturation to see if there was a way to recover that, but it didn't seem to do the right thing. I believe the relevant parameter is the amount of light reaching the surface at a given altitude. Naturally, the terrain shader can't know that up front, but the weather system has all the the information needed. If anyone is interested in attacking that problem from the shader side by exposing a property which can dial the 'darkness' of distant objects when they start to lose their color, I'd be happy to do my part from the weather side and cook up a model which sets the parameter value dependent on conditions. Part of the problem is that FlightGear almost always renders ideal situations for the skydome. If you look at this picture you see there are situations where white fog is natural: http://upload.wikimedia.org/wikipedia/commons/2/2a/St.Gilgen_Panorama_2007-02-22.jpg But you obviously won't get that with the sun hidden behind a cloudy sky. Erik -- Simplify data backup and recovery for your virtual environment with vRanger. Installation's a snap, and flexible recovery options mean your data is safe, secure and there when you need it. Data protection magic? Nope - It's vRanger. Get your free trial download today. http://p.sf.net/sfu/quest-sfdev2dev ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
