Re: [osg-users] 回复： Re: multi translucent g eometry
That reminds me of an issue I have not resloved yet. Our space ships have thruster engines and I use an image map with transparency and point it back at the camera to make a pretty glow around it. (First off, is this the best way to do it? I have thought that perhaps a shader would work better, but I have not had a chance to learn about how to write shaders yet. So much to learn, so little time). Anyway, In some ships there are banks of engines, and it is pretty easy to get the problem where these transparent images intersect with each other, and you get depth sorting issues that way. I did work out a way to make these engine flare images point, rather than right at the camera, all along parallel lines with the camera's line of sight, and that helped tremendously, but you can still get in positions where the images happen to line up along the same depth, and you see some funky tearing and the like due to depth fighting. Is there a way to handle this better? Should I try to apply other bins to the different engines? What are the rules wrt that? It sounds like I need to read up on the glDepth and osg::Depth. Any other recommendations? I was running into problems rendering planet halos too. Should the halo be in front of the planet or behind it? probably the same kind of thing going on. Regards, -- Rick 2008/7/13 小 杨 [EMAIL PROTECTED]: Thanks! I'll try it! *Peter Wraae Marino [EMAIL PROTECTED]* 写道： Hi ?? (can't see your name), Are you sure zbuffer isn't falling for your 2nd geometry object? Also having equal depths is probably not a good idea? You need to render your objects from back to front order. When you have transparent objects you should set the stateset stateset-setRenderBinDetails(10,DepthSortedBin); this will render the objects from back to front order... but note they will not sort the polygons for the individual geometry. 2008/7/13 小 杨 [EMAIL PROTECTED]: multi translucent geometry with equal depth but alpha value is not equal. when i render these geometry ,i can not see all geometry! Why ? Can everyone give me some advice! Thanks! -- 雅虎邮箱，您的终生邮箱！ http://cn.mail.yahoo.com/ ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org -- Regards, Peter Wraae Marino www.osghelp.com - OpenSceneGraph support site ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org -- 雅虎邮箱，您的终生邮箱！ http://cn.mail.yahoo.com/ ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org -- Rick Check us out at http://fringe-online.com/ ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] 回复： Re: multi translucent g eometry
I'm no expert in this area but have had to do some pretty weird things in the past to get transparency working right for some odd scenes... One thing you might try is to disable z-buffer writes (not tests) for the flares. Depending on your blending, this can add other types of artifacts but I think in your case they will be very subtle... versus the z-fighting you are seeing. (You will obviously want them to be drawn last just like normal transparency.) Just an idea... -Paul Rick Pingry wrote: That reminds me of an issue I have not resloved yet. Our space ships have thruster engines and I use an image map with transparency and point it back at the camera to make a pretty glow around it. (First off, is this the best way to do it? I have thought that perhaps a shader would work better, but I have not had a chance to learn about how to write shaders yet. So much to learn, so little time). Anyway, In some ships there are banks of engines, and it is pretty easy to get the problem where these transparent images intersect with each other, and you get depth sorting issues that way. I did work out a way to make these engine flare images point, rather than right at the camera, all along parallel lines with the camera's line of sight, and that helped tremendously, but you can still get in positions where the images happen to line up along the same depth, and you see some funky tearing and the like due to depth fighting. Is there a way to handle this better? Should I try to apply other bins to the different engines? What are the rules wrt that? It sounds like I need to read up on the glDepth and osg::Depth. Any other recommendations? I was running into problems rendering planet halos too. Should the halo be in front of the planet or behind it? probably the same kind of thing going on. Regards, -- Rick 2008/7/13 小 杨 [EMAIL PROTECTED] mailto:[EMAIL PROTECTED]: Thanks! I'll try it! */Peter Wraae Marino [EMAIL PROTECTED] mailto:[EMAIL PROTECTED]/* 写道： Hi ?? (can't see your name), Are you sure zbuffer isn't falling for your 2nd geometry object? Also having equal depths is probably not a good idea? You need to render your objects from back to front order. When you have transparent objects you should set the stateset stateset-setRenderBinDetails(10,DepthSortedBin); this will render the objects from back to front order... but note they will not sort the polygons for the individual geometry. 2008/7/13 小 杨 [EMAIL PROTECTED] mailto:[EMAIL PROTECTED]: multi translucent geometry with equal depth but alpha value is not equal. when i render these geometry ,i can not see all geometry! Why ? Can everyone give me some advice! Thanks! 雅虎邮箱，您的终生邮箱！ http://cn.mail.yahoo.com/ ___ osg-users mailing list osg-users@lists.openscenegraph.org mailto:osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org -- Regards, Peter Wraae Marino www.osghelp.com http://www.osghelp.com/ - OpenSceneGraph support site ___ osg-users mailing list osg-users@lists.openscenegraph.org mailto:osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org 雅虎邮箱，您的终生邮箱！ http://cn.mail.yahoo.com/ ___ osg-users mailing list osg-users@lists.openscenegraph.org mailto:osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org -- Rick Check us out at http://fringe-online.com/ ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] 回复： Re: multi translucent g eometry
Hi Rick, I agree with Paul. Turn off your z-buffer. If this effect is for thrusters then you should perhaps look into additive blending instead and this should create a better effect.. the more thrusters the brighter the become. A screenshot of your problem would help a lot (if possible). regards, Peter http://osghelp.com 2008/7/14 Paul Speed [EMAIL PROTECTED]: I'm no expert in this area but have had to do some pretty weird things in the past to get transparency working right for some odd scenes... One thing you might try is to disable z-buffer writes (not tests) for the flares. Depending on your blending, this can add other types of artifacts but I think in your case they will be very subtle... versus the z-fighting you are seeing. (You will obviously want them to be drawn last just like normal transparency.) Just an idea... -Paul Rick Pingry wrote: That reminds me of an issue I have not resloved yet. Our space ships have thruster engines and I use an image map with transparency and point it back at the camera to make a pretty glow around it. (First off, is this the best way to do it? I have thought that perhaps a shader would work better, but I have not had a chance to learn about how to write shaders yet. So much to learn, so little time). Anyway, In some ships there are banks of engines, and it is pretty easy to get the problem where these transparent images intersect with each other, and you get depth sorting issues that way. I did work out a way to make these engine flare images point, rather than right at the camera, all along parallel lines with the camera's line of sight, and that helped tremendously, but you can still get in positions where the images happen to line up along the same depth, and you see some funky tearing and the like due to depth fighting. Is there a way to handle this better? Should I try to apply other bins to the different engines? What are the rules wrt that? It sounds like I need to read up on the glDepth and osg::Depth. Any other recommendations? I was running into problems rendering planet halos too. Should the halo be in front of the planet or behind it? probably the same kind of thing going on. Regards, -- Rick 2008/7/13 小 杨 [EMAIL PROTECTED] mailto:[EMAIL PROTECTED]: Thanks! I'll try it! */Peter Wraae Marino [EMAIL PROTECTED] mailto:[EMAIL PROTECTED]/* 写道： Hi ?? (can't see your name), Are you sure zbuffer isn't falling for your 2nd geometry object? Also having equal depths is probably not a good idea? You need to render your objects from back to front order. When you have transparent objects you should set the stateset stateset-setRenderBinDetails(10,DepthSortedBin); this will render the objects from back to front order... but note they will not sort the polygons for the individual geometry. 2008/7/13 小 杨 [EMAIL PROTECTED] mailto:[EMAIL PROTECTED]: multi translucent geometry with equal depth but alpha value is not equal. when i render these geometry ,i can not see all geometry! Why ? Can everyone give me some advice! Thanks! 雅虎邮箱，您的终生邮箱！ http://cn.mail.yahoo.com/ ___ osg-users mailing list osg-users@lists.openscenegraph.org mailto:osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org -- Regards, Peter Wraae Marino www.osghelp.com http://www.osghelp.com/ - OpenSceneGraph support site ___ osg-users mailing list osg-users@lists.openscenegraph.org mailto:osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org 雅虎邮箱，您的终生邮箱！ http://cn.mail.yahoo.com/ ___ osg-users mailing list osg-users@lists.openscenegraph.org mailto:osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org -- Rick Check us out at http://fringe-online.com/ ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org ___ osg-users mailing list
