As a followup to the Sketchup for Backgrounds mini-series, I want to explain the concept of a 'paint-over'. This is not an excuse to skip learning to draw, but rather a shortcut for experienced painters. Before digital art was possible, commercial artists have done plenty of tracing in their work - and it was totally acceptable. This was not because the artists weren't very good at drawing - it was merely a time saver which allowed them to meet their deadlines. Using a 3D render (from sketchup or elsewhere) is the same concept -- it saves time for the artist. Again, it's not a pass which allows you to skip learning perspective drawing. Update: In response to some of the comments about the Sketchup series, I've created a quick video which will hopefully clear up the confusion. View it here.