OverlayNode.cpp has some shader code in it you might look at. In osgEarth we pass in a texgen matrix in a uniform, then in the vertex shader say:
gl_TexCoord[1] = texGenMatrix * osg_ViewMatrixInverse * gl_ModelViewMatrix * gl_Vertex; Then in the frag shader: vec2 tc = gl_TexCoord[1].xy / gl_TexCoord[1].q; vec4 texel = texture2D( texture_1, tc ); Or, I I believe you could also call: vec4 texel = texture2Dproj( projTex, gl_TexCoord[1] ); ..but I've never tried it. HTH. Glenn Waldron / @glennwaldron On Wed, May 9, 2012 at 3:12 PM, Loren Hoffman <[email protected]>wrote: > Glenn,**** > > ** ** > > Thanks for the response. I got the texture showing up in a test scenario > but am having a problem computing the texture coordinates. I looked through > the overlaynode’s header file and didn’t see anything which I could use to > compute the texture coordinates but did find that the implementation file > has some code for creating a matrix which can (I think) convert the > gl_Vertex into a valid coordinate but then I couldn’t find anything > specifying where it would be bound to. I randomly tried the first few > gl_TextureMatrices but either they don’t contain the matrix or I am using > it wrong. Currently I am attempting:**** > > ** ** > > vec4 col = texture2D(overlay, (gl_TextureMatrix[1] * gl_Vertex).xy);**** > > ** ** > > where using index 1 is just one of the tests. Any help would again be > appreciated. **** > > ** ** > > Thanks,**** > > - Loren**** > > ** ** > > *From:* [email protected] [mailto: > [email protected]] *On Behalf Of *Glenn Waldron > *Sent:* Wednesday, May 09, 2012 1:17 PM > *To:* OpenSceneGraph Users > *Subject:* Re: [osg-users] osgSim::OverlayNode and Point Clouds**** > > ** ** > > Loren, **** > > ** ** > > If your point cloud has a custom shader, make sure that shader is > rendering the projected texture used by OverlayNode.**** > > > Glenn Waldron / @glennwaldron > > **** > > On Wed, May 9, 2012 at 2:05 PM, Loren Hoffman <[email protected]> > wrote:**** > > Hello All,**** > > **** > > I have a setup where I need to project an overlay node’s sub graph onto a > point cloud. We already have it setup to overlay onto geometry created with > VPB and I was hoping it would “just work”™ for the clouds. Unfortunately it > seems to have no effect at all on cloud despite it having been inserted > into the graph in the same manner that the vpb geometry was. The point > cloud is being rendered with a custom shader setup but I didn’t come across > anything saying that that would be an issue. Is there anything I need to do > to the point cloud’s graph to make it so it will accept the overlay or is > this a limitation of the overlay system? Thanks in advance,**** > > **** > > - Loren**** > > > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org* > *** > > ** ** > > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > >
_______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
