Hi Adrien, The way to do colour look up tables in OpenGL these days is to use a fragment program that reads the source texture which is an 8bit intensity/alpha texture and then look this up a second texture. So create the two osg::Image, one for the 8bit data, and then a second one for the RGBA look up table. Assign these two osg::Image to Texture2D and an Texture1D respectively.
The is an osg::TransferFunction1D class for helping create RGBA look up tables, this is used in osgVolume so you could look at this as an example. Robert. On Tue, Jun 29, 2010 at 7:02 PM, Adrien Chassard <[email protected]> wrote: > Hi, > > I try to load a 8bits image and create an osg::Texture2D with it. I search > all the day but without sucess. > > It seems that the image load by osgDB::readImageFile(...) is transform in a > 32 bits image. Is it possible to load it as 8bits image with an associated > look up table ? (I didn't find attribut in osg::Image that could correspond > to a lut, is there one ?) > > However if I can load my image as a 8 bits image, I don't know how I can > associate the color table to the texture, is there a way to do that ? > > In fact and to clarify what I mean, here is the code in OpenGL I would like > to translate in OpenSceneGraph : > > glColorTableEXT(GL_TEXTURE_2D, GL_RGBA8, 256, GL_RGBA, GL_UNSIGNED_BYTE, > colorTable); > glTexImage2D(GL_TEXTURE_2D, 0, GL_COLOR_INDEX8_EXT, width, height, 0, > GL_COLOR_INDEX, GL_UNSIGNED_BYTE, texture); > > I hope I was enough clear. Sorry if I wasn't. > > Thank you very much for your help. > > Cheers, > Adrien > > ------------------ > Read this topic online here: > http://forum.openscenegraph.org/viewtopic.php?p=29500#29500 > > > > > > _______________________________________________ > 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
