Status panes in front of scene?

If you want a really nice simple solution then have a look at AntTweakBar Very easy to use.

Thanks for the reply and for the link.

In reality I am more interested in learning the mechanics of doing it myself for the moment. I am still learning OpenGL and feel that I would rather understand how this is done in OpenGL, before using a ready built solution.

The basics of a 2D overlay/HUD are to render your 3D scene with a perspective projection and then switch to an orthographic projection (with glOrtho) to render your status panel. There's also a nice entry in the forum FAQ about 2D with OpenGL.

I actually just worked this out myself. Here is some psuedocode of what I did:

pushPerspectiveProjection();

while(running)
pushOrthographicProjection();
drawUI();
popProjection();

drawScene();
end

pushOrthographicProjection()
glPushAttrib(GL_TRANSFORM_BIT);
glMatrixMode(GL_PROJECTION);
glPushMatrix();
glLoadIdentity();
glOrtho(0.0f, width, 0.0f, height, -1.0f, 1.0f);
glPopAttrib();
end

Thanks, this work beautifully. Some actual code, in Java using JOGL, for anyone else who happens to come along this thread:

    void pushOrthographicProjection( GL gl ) {        gl.glPushAttrib(GL.GL_TRANSFORM_BIT);        gl.glMatrixMode(GL.GL_PROJECTION);        gl.glPushMatrix();        gl.glLoadIdentity();        gl.glOrtho(0.0f, getWidth(), 0.0f, getHeight(), -1.0f, 1.0f);          }    void popOrthographicProjection( GL gl ) {        gl.glPopMatrix();        gl.glPopAttrib();     }

Just make sure you don't forget to toggle the matrix mode back before drawing ;)

Quote:

Original post by ajmas void pushOrthographicProjection( GL gl ) { gl.glPushAttrib(GL.GL_TRANSFORM_BIT); gl.glMatrixMode(GL.GL_PROJECTION); gl.glPushMatrix(); gl.glLoadIdentity(); gl.glOrtho(0.0f, getWidth(), 0.0f, getHeight(), -1.0f, 1.0f); gl.glMatrixMode(GL.GL_MODELVIEW); } void popOrthographicProjection( GL gl ) { gl.glMatrixMode(GL.GL_PROJECTION); gl.glPopMatrix(); gl.glMatrixMode(GL.GL_MODELVIEW); gl.glPopAttrib(); }