Shapes in three dimensions require spatial thinking and a knowledge of perspective, as well as an idea of lighting. By determining the shape to draw and the angle it's being viewed from, the artist or illustrator can draw 3-D shapes more easily.
- Set the vanishing point or points of perspective
The vanishing point is an imaginary point toward which all lines in 3-D space converge. It is located in the center of the horizon from the viewer's perspective. It's best to lightly mark the vanishing point on the paper.
- Draw the flat plane of the shape in the foreground
For example, you're drawing the basic frame of a building, it might be a rectangle. Draw lightly; many lines are later erased or traced over in the process of drawing, so light lines prevent the art from looking too cluttered.
- Draw lines from the vertices of the shape to the appropriate vanishing point
Use a ruler to keep the lines straight, especially in architectural design.
- Draw the background part of the shape
After doing this, connect the lines. Determine where the light source is, and shade accordingly. For example, a light source from above puts undersides of shapes in the shade.