I've noticed that with OSG 3.x, the behaviour of some shaders, especialy in relation with the alpha channel changed.
Most notable in what is related to this bug: http://code.google.com/p/flightgear-bugs/issues/detail?id=427 what follows is a copy of my post on that bug report: Did a bit of testing on this one, and I think I found a fix. It affects not only airplane models, but anything that has a texture with an alpha channel when shaders are enabled. My theory is something changed in the way OSG handles things in shaders, but I'm no expert. Apparently in this line (line 48 in default.frag, also present in similar form in models-default.frag and tree frag): gl_FragColor = mix(gl_Fog.color, fragColor, fogFactor); fragColor.a gets mixed too in newer versions of OSG, as oposed to OSG versions pre 3.0 where the mix operation would affect only fragColor.rgb. Changing the line to this: gl_FragColor = vec4(mix(gl_Fog.color.rgb, fragColor.rgb, fogFactor), fragColor.a); fixes it here, and applying the same to tree.frag and model-default.frag fixes similar problems with trees and scenery objects. Easily testable with --visibility-miles=2 to get a thicker fog. ------------------------------------------------------------------------------ Doing More with Less: The Next Generation Virtual Desktop What are the key obstacles that have prevented many mid-market businesses from deploying virtual desktops? How do next-generation virtual desktops provide companies an easier-to-deploy, easier-to-manage and more affordable virtual desktop model.http://www.accelacomm.com/jaw/sfnl/114/51426474/ _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
