The document discusses the key elements of three-dimensional design including form, line, plane, space, texture, color, and time. It provides definitions and examples of each element. Form can be volumes, masses, static or dynamic. Lines have qualities like orientation, direction, and continuity. Planes can be used to create volumes and masses. Space can be positive or negative. Texture provides visual or tactile qualities. Color has properties like hue, value, intensity, and temperature. Time can be actual, implied, or viewing time for analysis.