On Sun, Jun 22, 2008 at 12:37 PM, Robert Osfield <[EMAIL PROTECTED]> wrote: > Hi Sherman, > > You could try using an osg::AutoTransform that is positioned at your > XYZ and set up to scale to screen coords and rotate to screen, then > have the subraph by offset up the Y axis (effectively in screen space) > to give you the offset you want.
The last bit - "have the subraph by offset up the Y axis (effectively in screen space) to give you the offset you want." - what exactly do you suggest? What I require is an approximate offset in pixels. For example, if I want a node (lets use text as an example) to be at position XYZ in world coordinates and then offset by 45 pixels along the Y axis - what do you suggest? I have one method working that I'm not pleased with performance wise. The crucial bit is getting close to the number of pixels specified to be offset by. > > Cheers, > Robert. > > On Sun, Jun 22, 2008 at 1:28 AM, sherman wilcox > <[EMAIL PROTECTED]> wrote: >> I have nodes (models, text, etc.) that are positioned in XYZ >> coordinates that I wish to offset in screen space. My question is >> what's the best/fastest way to do this. An example follows. I have a >> piece of text that acts as a label for a point on a sphere. In this >> case that sphere is an osg ellipsoid model generated by virtual planet >> builder. I position the text at a given lat/lon/altitude which I >> translate to a XYZ world coordinate. However, I wish to offset the >> text in screen space by X,Y pixels. Imagine you want to label a point >> of interest on this globe but you want the label itself to be offset >> (updated every frame) by X pixels in the x-dimension and Y pixels in >> the y-dimension. I have one osg::MatrixTransform node acting as the >> parent of each text object. I have about 100 of these labels objects. >> I need to update the offset of the text every few frames. Doesn't have >> to be every frame, I can accept lazy updates - but it is something >> that needs to occur rather frequently. >> >> What's the best way to accomplish this? I have something working but >> it's rather slow with 50 or more objects. I'm using IntersectVisitor >> in the algorithm which is killing performance. Any suggestions? >> _______________________________________________ >> 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
