19. Polygon Rendering Modes

• Polygons do not have to be filled

• We have 3 modes to draw polygons:

  
      GL_FILL  // what we've been using
      GL_LINE  // 3D wireframe
      GL_POINT // just the vertices
  
  

• Call glPolygonMode() to change rendering mode:

  
      // renders front and back facing polygons in wireframe
      glPolygonMode( GL_FRONT_AND_BACK, GL_LINE );