[osg-users] Node needs to render at least one pixel

Jean-Sébastien Guay jean-sebastien.guay at cm-labs.com
Tue Jul 22 13:39:41 PDT 2008


Hello Philip,

> As this iamge shrinks into the distance, it (still) becomes invisible.
> My coworker (who is knowledgeable of OpenGL, but not so much of OpenSceneGraph), suggests MIP-mapping.  I can move to that, it that's the next step.

I don't think mipmapping will solve the problem, because that just 
changes how the texture is filtered when it is minified and magnified. 
If the quad covers 0 pixels, the filtering of the texture on the quad 
doesn't really matter, the quad still won't be visible.

I really don't know what to suggest as your usage is pretty uncommon... 
You could try using an osg::AutoTransform to keep the quad the same size 
(in image space) independently of its distance from the viewer. Not sure 
if that's what you want. Otherwise, attach a callback to the transform 
above your quad, which would change the transform's scale when the 
distance from the viewpoint gets larger than some threshold.

Sorry I can't help more.

J-S
-- 
______________________________________________________
Jean-Sebastien Guay    jean-sebastien.guay at cm-labs.com
                                http://www.cm-labs.com/
                         http://whitestar02.webhop.org/



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