Re: [Flightgear-devel] Normal map shader example - c172p
I am by no means an aerodynamicist myself either, but I'll give my 2 cents. Like you said, as smooth surfaces as possible reduce drag and therefore improve their flight dynamics. For example on gliders, it is normal to wash the entire plane after a days worth of flying because of the squashed bugs, which would reduce the gliders gliding ratio due to increased drag. Then again, it's probable that not all planes require such great detail to their flight dynamics. I think there's a trade off between drag (and induced fuel consumption) and cost. -- Mats Rauhala sip:mas...@ekiga.net pgpPaLrS2r6lI.pgp Description: PGP signature -- ThinkGeek and WIRED's GeekDad team up for the Ultimate GeekDad Father's Day Giveaway. ONE MASSIVE PRIZE to the lucky parental unit. See the prize list and enter to win: http://p.sf.net/sfu/thinkgeek-promo___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Normal map shader example - c172p
Simon Hollier wrote: Here's a bunch of random photos from a 172S: http://hellosimon.org/35117/ There's some close ups of some rivets in some of them. Hope that helps, Simon Very useful. Thanks also for the cockpit details. While it's not a p model, I'm sure I can use some of the photos to improve our model. Bertrand Coconnier wrote: Anyway my contribution was not much worth it... Next time I will check closer ^_^ Not at all - it raised some interesting points and encourage other comments. David Megginson wrote: All the Cessna 172's I've seen have had protruding rivets, but the heads don't stick out much, and the paint smooths out the edges to the point that they're just gentle bumps -- a 172's wing doesn't look like a steam boiler. As pointed out by Martin and yourself, I definitely need to reduce the height of the normal map. That is pretty straightforward, though I may not get to it until next week. -Stuart -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Normal map shader example - c172p
2010/4/9 Stuart Buchanan stuar...@gmail.com: Frederic Bouvier wrote: Glad to see the effect is used. I noticed the bump is reverted on one axis. In a previous thread, I wrote : I use the GIMP normal map plug-in to create my normal maps. Here are two example. A bump : http://frbouvi.free.fr/flightsim/gimp-normalmap-bump.png A hole : http://frbouvi.free.fr/flightsim/gimp-normalmap-hole.png They are created from the same height field image. Reds should point to the bottom right and greens should points to the top left. More precisely: #FF7F7F points to the right #7FFF7F points to the top #007F7F points to the left #7F007F points to the bottom These are the only two realistic combinations. Remember that for OpenGL the origin of the image is the bottom left when the origin of an image is the top left, so that's why an axis should be reverted. Looking closely at the wing map : http://frbouvi.free.fr/flightsim/gimp-normalmap-c172.png It appears that reds are pointing to the top right and greens to the bottom left. You may need to check the 'Invert Y' box in order to get them right. Thanks for the help. I've updated the normal maps, and included this information in the wiki article. This is some nice artistic/graphical work indeed, however, I am afraid this is not very realistic. If you want Cessna aerodynamicists to die from an heart attack, just show them this picture ^_^ In real life, and on most modern aircrafts, you do not have such protruding rivets unless you want your fuel consumption to go through the roof. Countersunk head rivets are used nowadays and their number and position are the result of a tough battle between the design office (who want a strong/cheap/light structure) and the aerodynamics office (who want very smooth/expensive air washed surfaces) ^_^ The result of these hard negotiations is that rivets *must have* a countersunk head (it is a minimum to enter a round of negotiation ^_^), there must be as few as possible of them, the gap between the rivet head and the countersunk hole should often be filled by a sealant (or at least by paint ^_^ both of them cracking in service anyway ^_^) and rivets with protruding heads are not an option (don't even think about them, unless you want to be crucified on the public place ^_^). The result, unfortunately, is not very spectacular as can be seen on the picture that Martin Spott sent a few days ago (http://foxtrot.mgras.net/bitmap/FGFS/DEEQA-Oelklappe.jpg) but it significantly improves your aircraft performance (and make the aerodynamicists happy - which is priceless). Cheers, Bertrand. P.S. No offence is meant to the aerodynamicists. They are very smart guys (you have to when you are involved in CFD) and most of them are really cool guys. Furthermore they are the greenest dept of an aircraft manufacturer since all their work is dedicated to the reduction of the fuel consumption ^_^ -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Normal map shader example - c172p
Bertrand wrote: This is some nice artistic/graphical work indeed, however, I am afraid this is not very realistic. If you want Cessna aerodynamicists to die from an heart attack, just show them this picture ^_^ :) I was basing the work on some photos I found on the Cessna website. This one in particular seemed to show raised rivets on the wing: http://www.cessna.com/MungoBlobs/832/502/sin_haw_flt18_hires.jpg Perhaps what I'm seeing there isn't actually protruding rivets at all. Is there any height change there at all, or are the surfaces completely smooth? I could obviously tone down the effect significantly to make them protrude less if that is more realistic. BTW - we're modeling a P model, if that makes any difference. -Stuart -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Normal map shader example - c172p
Here's a bunch of random photos from a 172S: http://hellosimon.org/35117/ There's some close ups of some rivets in some of them. Hope that helps, Simon On Tue, Apr 13, 2010 at 4:48 PM, Stuart Buchanan stuar...@gmail.com wrote: Bertrand wrote: This is some nice artistic/graphical work indeed, however, I am afraid this is not very realistic. If you want Cessna aerodynamicists to die from an heart attack, just show them this picture ^_^ :) I was basing the work on some photos I found on the Cessna website. This one in particular seemed to show raised rivets on the wing: http://www.cessna.com/MungoBlobs/832/502/sin_haw_flt18_hires.jpg Perhaps what I'm seeing there isn't actually protruding rivets at all. Is there any height change there at all, or are the surfaces completely smooth? I could obviously tone down the effect significantly to make them protrude less if that is more realistic. BTW - we're modeling a P model, if that makes any difference. -Stuart -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel -- Simon Hollier -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Normal map shader example - c172p
2010/4/13 Stuart Buchanan stuar...@gmail.com: Bertrand wrote: This is some nice artistic/graphical work indeed, however, I am afraid this is not very realistic. If you want Cessna aerodynamicists to die from an heart attack, just show them this picture ^_^ :) I was basing the work on some photos I found on the Cessna website. This one in particular seemed to show raised rivets on the wing: http://www.cessna.com/MungoBlobs/832/502/sin_haw_flt18_hires.jpg Perhaps what I'm seeing there isn't actually protruding rivets at all. Is there any height change there at all, or are the surfaces completely smooth? I could obviously tone down the effect significantly to make them protrude less if that is more realistic. BTW - we're modeling a P model, if that makes any difference. -Stuart Well spotted Stuart. They look very much like protruding rivets. May be what I reported above is limited to some specific class of aircrafts ? A Cessna C172 is a relatively cheap aircraft flying at low speeds, may be this is why Cessna are using protruding rivets (which are cheaper than countersunk rivets). May be it only makes a difference at higher speeds ? It seems I have extrapolated my experience to an area where it does not apply ^_^ As you may have guessed I am not an aerodynamicist myself, moreover my own experience is limited to airliners where, I think, the criteria are more stringent than for small aircrafts... Or may be in Cessna the design office have won the battle against aerodynamics ? ^_^ Anyway my contribution was not much worth it... Next time I will check closer ^_^ Cheers, Bertrand. -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Normal map shader example - c172p
All the Cessna 172's I've seen have had protruding rivets, but the heads don't stick out much, and the paint smooths out the edges to the point that they're just gentle bumps -- a 172's wing doesn't look like a steam boiler. IIRC, the Mooney has countersunk rivets, which is why it can go so fast. All the best, David On Tue, Apr 13, 2010 at 5:18 PM, Bertrand Coconnier bcoco...@gmail.com wrote: 2010/4/13 Stuart Buchanan stuar...@gmail.com: Bertrand wrote: This is some nice artistic/graphical work indeed, however, I am afraid this is not very realistic. If you want Cessna aerodynamicists to die from an heart attack, just show them this picture ^_^ :) I was basing the work on some photos I found on the Cessna website. This one in particular seemed to show raised rivets on the wing: http://www.cessna.com/MungoBlobs/832/502/sin_haw_flt18_hires.jpg Perhaps what I'm seeing there isn't actually protruding rivets at all. Is there any height change there at all, or are the surfaces completely smooth? I could obviously tone down the effect significantly to make them protrude less if that is more realistic. BTW - we're modeling a P model, if that makes any difference. -Stuart Well spotted Stuart. They look very much like protruding rivets. May be what I reported above is limited to some specific class of aircrafts ? A Cessna C172 is a relatively cheap aircraft flying at low speeds, may be this is why Cessna are using protruding rivets (which are cheaper than countersunk rivets). May be it only makes a difference at higher speeds ? It seems I have extrapolated my experience to an area where it does not apply ^_^ As you may have guessed I am not an aerodynamicist myself, moreover my own experience is limited to airliners where, I think, the criteria are more stringent than for small aircrafts... Or may be in Cessna the design office have won the battle against aerodynamics ? ^_^ Anyway my contribution was not much worth it... Next time I will check closer ^_^ Cheers, Bertrand. -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Normal map shader example - c172p
Hi Stuart, - Stuart Buchanan a écrit : Hi All, I've just updated the c172p to make use of the bumpspec Effect for a bump-map. I've still to get the rivet separation right, but the effect so far is rather pleasing: http://www.nanjika.co.uk/flightgear/fgfs-screen-004.png Glad to see the effect is used. I noticed the bump is reverted on one axis. In a previous thread, I wrote : I use the GIMP normal map plug-in to create my normal maps. Here are two example. A bump : http://frbouvi.free.fr/flightsim/gimp-normalmap-bump.png A hole : http://frbouvi.free.fr/flightsim/gimp-normalmap-hole.png They are created from the same height field image. Reds should point to the bottom right and greens should points to the top left. More precisely: #FF7F7F points to the right #7FFF7F points to the top #007F7F points to the left #7F007F points to the bottom These are the only two realistic combinations. Remember that for OpenGL the origin of the image is the bottom left when the origin of an image is the top left, so that's why an axis should be reverted. Looking closely at the wing map : http://frbouvi.free.fr/flightsim/gimp-normalmap-c172.png It appears that reds are pointing to the top right and greens to the bottom left. You may need to check the 'Invert Y' box in order to get them right. -Fred -- Frédéric Bouvier http://my.fotolia.com/frfoto/ Photo gallery - album photo http://www.youtube.com/user/fgfred64 Videos -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Normal map shader example - c172p
Hi All, I've just updated the c172p to make use of the bumpspec Effect for a bump-map. I've still to get the rivet separation right, but the effect so far is rather pleasing: http://www.nanjika.co.uk/flightgear/fgfs-screen-004.png Like most of the other shader effects, this looks better in-sim than in a screenshot. In particular the rivets on the cowling when viewed from the cockpit are rather nice when turning. I've also written a wiki article to help others interested in using this shader: http://wiki.flightgear.org/index.php/Howto:_Use_The_Normal_Map_Effect_in_A ircraft I'm interested in other people's performance experience with this shader. The normal maps are rather large, though they compress down very well. Nice work, thanks for the wiki. It cleared some things for me. Development is currently so fast, it's hard to keep up! Torsten -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Normal map shader example - c172p
Am Donnerstag, den 08.04.2010, 00:13 +0100 schrieb Stuart Buchanan: Hi All, I've just updated the c172p to make use of the bumpspec Effect for a bump-map. I've still to get the rivet separation right, but the effect so far is rather pleasing: http://www.nanjika.co.uk/flightgear/fgfs-screen-004.png Like most of the other shader effects, this looks better in-sim than in a screenshot. In particular the rivets on the cowling when viewed from the cockpit are rather nice when turning. I've also written a wiki article to help others interested in using this shader: http://wiki.flightgear.org/index.php/Howto:_Use_The_Normal_Map_Effect_in_Aircraft I'm interested in other people's performance experience with this shader. The normal maps are rather large, though they compress down very well. I've tested a bit and noticed that regarding size, the resolution of the normalmap doesn't matter. An image of 4096x4096 has nearly the same size than a 2048x2048 scaled version of the same image (which looks rather ugly in-sim btw,). However this is the case when the image is scaled before applying the normalmap filter. If the resulting normalmap gets scaled, the smaller resolution image is even larger in filesize than the original. The striking thing with using the shader is that it is now possible to have smaller image files for liveries as now only the colour is needed. Details can now be done in the shader. This reduces the lag while selecting different liveries. Greetings -Stuart -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel -- Detlef Faber http://www.sol2500.net/flightgear -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Normal map shader example - c172p
Detlef Faber wrote: The striking thing with using the shader is that it is now possible to have smaller image files for liveries as now only the colour is needed. Details can now be done in the shader. This reduces the lag while selecting different liveries. Good to know, I might want to apply it to the F-16 then. Thanks for the hint. Erik -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Normal map shader example - c172p
Frederic Bouvier wrote: Glad to see the effect is used. I noticed the bump is reverted on one axis. In a previous thread, I wrote : I use the GIMP normal map plug-in to create my normal maps. Here are two example. A bump : http://frbouvi.free.fr/flightsim/gimp-normalmap-bump.png A hole : http://frbouvi.free.fr/flightsim/gimp-normalmap-hole.png They are created from the same height field image. Reds should point to the bottom right and greens should points to the top left. More precisely: #FF7F7F points to the right #7FFF7F points to the top #007F7F points to the left #7F007F points to the bottom These are the only two realistic combinations. Remember that for OpenGL the origin of the image is the bottom left when the origin of an image is the top left, so that's why an axis should be reverted. Looking closely at the wing map : http://frbouvi.free.fr/flightsim/gimp-normalmap-c172.png It appears that reds are pointing to the top right and greens to the bottom left. You may need to check the 'Invert Y' box in order to get them right. Thanks for the help. I've updated the normal maps, and included this information in the wiki article. -Stuart -- Download Intel#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
