On 7/26/07, Vivian Meazza <[EMAIL PROTECTED]> wrote: > Hans Fugal > I have never seen or heard of any problem with osg and clouds of any sort. > Xnview reports no errors in cirrus.rgba, or with any of the textures. > Perhaps you have corrupted the clouds textures locally? Did you open them in > any editor before you saw the weird effects? Of course, people might be just > accepting the weirdness, and not reporting it.
Jester, jentron, and I did some investigating last night. The textures in question seem to be a less-common format that some programs understand and others do not. For example, IrfanView and ImageMagick both treat cirrus.rgba similarly - it looks something like this: http://hans.fugal.net/tmp/fg/cirrus-abstractart.png . I think we can agree this is not what the sky should look like. Some programs refuse to open it at all, complaining that they don't recognize the format. Jester has a better understanding about just what this format is, but I believe the salient features are 2-channel: greyscale with alpha. ImageMagick's identify(1) reports them as PseudoColor images (vs DirectColor) Gimp opens them fine, as does "osgviewer --image cirrus.rgba". The latter is most important, it means that OSG itself can handle this format. So we likely are looking at a memory corruption bug in OSG when this particular type of image is loaded. Something about the way things work on intel macs is causing the corruption to manifest itself where as it goes unnoticed on linux by sheer luck. Just a theory anyway. Incidentally, I have observed in both linux and osx in fg/osg that cloud layers don't work quite like I'd expect. If the weather is scattered clouds at 3000 ft and overcast at 5000, then when I'm sitting on the runway I see blue sky between the scattered clouds. It's not until I go above 3000 that suddenly there's overcast sky above me. -- Hans Fugal Fugal Computing ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
