Hm. Is it possible that texture mapping or lighting is enabled? If so, then you don't specify texcoords/normals, so you could be getting one texel spread across the whole primitive, or the last normal could've been facing away from the light. Either would explain the black primitive. Best way to manipulate State in a custom Drawable would be to create your own State object for that Drawable, and the ultimate reference material for that is to take a look at osgText::Text::drawImplementation(). The Text object derives from Drawable and manipulates State in this manner. -Paul
_____ From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Brian Sent: Monday, July 02, 2007 1:39 PM To: osg users Subject: [osg-users] Proper usage of Drawable::drawImplementation Hi, I am trying to learn how to create my own custom drawable objects, and I have run into a snag. I create a class derived from the Drawable class and provide the necessary functions. Currently, I'm drawing a single quad in my drawImplementation function. The quad renders, however if I try to associate a red color with the quad, the quad only renders as black. When setting up the scene, I create a geode and add my drawable to it. By itself, it renders as mentioned above, but if I also add a geometry object to the geode (also a quad), then my custom drawable renders properly as a solid red quad. The code for the drawImplementation is very simple. I'm wondering if I need to manipulate the osg::State object somehow, but I'm unclear as to how. code... void drawImplementation(osg::State &state) const { glColor3f(1, 0, 0); glBegin(GL_QUAD); glVertex3f(150, 150, 0); glVertex3f(150, 150, 150); glVertex3f(0, 150, 150); glVertex3f(0, 150, 0); glEnd(); } Incidentally, I'm still using OSG 1.2. Thanks for any help you might be able to give me. Brian
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