Hi Viggo, Have you tried to setup the glReadBuffer properly first. Take a look into osgPPU, this has already the functionality to read from textures (UnitOutCapture) and to be used for post-processing calculation like you have.
Maybe this could help you to solve the problem. Best regards, Art On Thursday 31 July 2008 08:48:19 Viggo Løvli wrote: > Hi, > > I am trying to write an intersect post-processing function that will read > the alpha value of the hit-location. I have so far managed to get the > texture coordinates for each collision point. I have also managed to find > which texture (in unit 0) that is used by the object that I collide with. > > I have a pointer to the texture: > osg::Texture2D* texture; > > The scene I am intersecting is read from a pre-created file and all > osgImage data is automatically deleted. So, I can not always use > texture->getImage() and read the pixels from there. > > In the cases where getImage returns a NULL pointer: > osg::Texture::TextureObject* to = texture->getTextureObject( 0 ); > glBindTexture( GL_TEXTURE_2d, to->_id ); > unsigned char data[4]; > glReadPixels( xLocation, yLocation, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, > data ); glBindTexture( GL_TEXTURE_2D, 0 ); > > This code compiles and it runs. The problem is that it always returns the > same values for RGB and A, nomatter what my xLocation and yLocation is. > > Can anybody see what I am doing wrong? > > Regards, > Viggo > > _________________________________________________________________ > Morsomme klipp, kjendiser og mer på MSN Video. > http://video.msn.com/?mkt=nb-no&from=HMTAG _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
