A two-dimensional drawing is limited by being somewhat unrealistic. A three-dimensional (3D) picture, however, is a much more realistic portrayal of an object or scene. The lines and colors of a 3D picture give the viewer a sense of the items being shaped beyond the scope of the picture.
1. Start with the basic lines in the shapes you are drawing. Once those are completed, make diagonal lines that extend the lines of the shape, going in only one direction.
2. Slant the new lines and have them running in the same general direction. The lines are then connected together. Use a pencil to experiment with different directions to see which one makes the scene look more realistic. Erase the practice lines and leave only the best ones on the drawing.
3. Practice by making a 3D picture of a square. Begin with the lines that form a square. Choose one direction and extend the box outside its four walls. Do this with lines coming from all four corners but heading in only one direction on one side of the square with the slanted lines running parallel to the original lines of the square. Connect the new lines into a new corner.
4. Use shading to depict light falling on the object. The shading will make the picture look more 3D by showing where light and shadow are falling around the shape of the object. Choose one direction that will be the light source. Use darker shadows for parts of an object that light will not be touching because of the shape or positioning of the object.