Re: [osg-users] Using image maps with materials
I have seen some examples, somewhere I think, where you could have one texture on the lit side of an object and then have another texture on the dark side. I am thinking of the earth where you could see lights in cities on the dark side. Did I really see that somewhere or is that my imagination? I have heard of using fragment shaders and it is something I would like to learn more about. Where can I find out about how to use "multi-pass technique" and/or "register"? On Tue, Jul 15, 2008 at 12:13 AM, Ulrich Hertlein <[EMAIL PROTECTED]> wrote: > Hello Rick, > > [EMAIL PROTECTED] wrote: > >> Is there a way to use image maps with some of the other material >> properties, like emission or specular or diffuse? I am working on ... >> > > how to use a reflection map, so I think I am ok there. Any way to use a > > map to define the emission, specularity, and diffuse amounts across a > > surface? > > There's no easy way to specify the material component that a texture should > affect (such as emissive, specular) in plain OpenGL. > > The way to go these days is a fragment shader. You could also use a > multi-pass technique to apply another texture. > > (Maybe register combiners offer something useful but I'm not sure about > that.) > > Cheers, > /ulrich > ___ > osg-users mailing list > osg-users@lists.openscenegraph.org > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > -- >> Rick Check us out at http://fringe-online.com/ ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Using image maps with materials
Hello Rick, [EMAIL PROTECTED] wrote: Is there a way to use image maps with some of the other material properties, like emission or specular or diffuse? I am working on ... > how to use a reflection map, so I think I am ok there. Any way to use a > map to define the emission, specularity, and diffuse amounts across a > surface? There's no easy way to specify the material component that a texture should affect (such as emissive, specular) in plain OpenGL. The way to go these days is a fragment shader. You could also use a multi-pass technique to apply another texture. (Maybe register combiners offer something useful but I'm not sure about that.) Cheers, /ulrich ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
[osg-users] Using image maps with materials
Hello All, Is there a way to use image maps with some of the other material properties, like emission or specular or diffuse? I am working on adding some functionality to the LWO reader. We have been able to get the transparancy working along with how LightWave does it, by taking the transparency mapped defined in lightwave and copying that into the alpha channel of the color map. I can see there are lots of examples about how to use a reflection map, so I think I am ok there. Any way to use a map to define the emission, specularity, and diffuse amounts across a surface? -- Thanks >> Rick Check us out at http://fringe-online.com/ ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
