Render Tip of the Week - Use edge lines for greater detail

Edge lines can be very useful for users who are trying to show off detail in a rendered image. Many times details can be washed out in renderings because of lighting and material choices but showing the edges in the rendering can help to make that detail stand out.

Kitchen rendered with edge lines .

Kitchen Rendered without edge lines - edge line detail is lost

Users could use a program such as Photoshop to blend two images together, one of the rendered image and one of only the edge lines, but this is time consuming and difficult, a better option would be to have it done for the user with their rendering program. If your renderer does support edge lines, then you will have the added advantage that the edge lines will appear in reflections, as well as the rendering.

See: Rendering with Edge Highlighting

(Model from the 3D Warehouse, Images and text from Dennis)