This drawing by the celebrated renderer Schell Lewis shows that a subtle use of shades and shadows can offset use of perspective in achieving a sense of depth. The relief and projection depend largely on the form and value of the shade and shadow tones. Note also the way Lewis handles the smaller detail in the shadow of the cornice.
I love the idea of studying the masters, like the renderer Schell Lewis, and using technology to capture the same feeling that they were able to capture using the pencil. Nowhere does it say we, architectural illustrators, have to show perspectives, just because we can. This entrance is a small part of a bigger picture, but Lewis was able to capture the architecture with a small vignette.