Robert, Thanks for the quick response. Doh, that was my first thought! But I got sidetracked when I saw that camera node in the scene and wondered what would happen if I took it out!
I think I will hack a renormalize option into osgconv and see what happens. However, I still do not understand why removing the cone drawable, which as far as I can see is switched off by the switch node, should make things appear to work. Roger > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:osg-users- > [EMAIL PROTECTED] On Behalf Of Robert Osfield > Sent: 02 July 2007 13:11 > To: osg users > Subject: Re: [osg-users] osgconv scaling affects colours > > Hi Roger, > > Lighting issues related to scaling are typically associated with the > scaling of normals causing problems with OpenGL lighting computation > See include/osg/Transform for details. > > Robert. > > On 7/2/07, Roger James <[EMAIL PROTECTED]> wrote: > > > > > > > > > > I am seeing some strange colour effects on a simple model exported from > > Google Sketchup. All these tests have been done on OSG 1.9.8 but with my > > Collada mods from 2.0 applied. If someone could verify the results on > 2.0 > > that would be helpful. The attached Collada file plank.dae was extracted > > from a kmz archive exported by Sketchup. The units for the file are > inches. > > If you display the file or its osg equivalent plank.osg (produced using > > osgconv with no parameters) you should see a lump of wood with a simple > > brown colouring. > > > > > > > > However I needed the model to be metric so I ran osgconv on it with "-s > > 0.0254,0.0254,0.0254" to put a scaling transform in it. The result of > this > > is attached as plankscaled.osg. When I look it this file in osgviewer, > > instead of seeing a nice brown plank I see a white one with some strange > > subtle directional colour effects overlaid on it. The geometry also > seems > > slightly distorted. How can a simple scaling transform produce such > effects. > > > > > > > > On looking into the collada file I saw that the scene in there included > a > > camera node. This is translated by the importer into MatrixTrasnform > node > > which holds a Switch node which holds a Geode containing a Cone > drawable. > > This cone drawable is switched off. So in theory it should have no > effect on > > the osg scene. I decided to hand edit the Collada camera node out of the > > Collada file. To my surprise (well not really J) the scaling operation > now > > worked exactly as expected. The results are attached as > > planknocamera.dae/osg and planknocamerascaled.osg. > > > > > > > > So firstly can someone verify this on 2.0 for me, and secondly does > anyone > > have any idea what is going on? > > > > > > > > My finger of suspicion is currently pointing at the optimizer. > > > > > > > > Roger > > _______________________________________________ > > osg-users mailing list > > [email protected] > > http://openscenegraph.net/mailman/listinfo/osg-users > > http://www.openscenegraph.org/ > > > > > _______________________________________________ > osg-users mailing list > [email protected] > http://openscenegraph.net/mailman/listinfo/osg-users > http://www.openscenegraph.org/ _______________________________________________ osg-users mailing list [email protected] http://openscenegraph.net/mailman/listinfo/osg-users http://www.openscenegraph.org/
