Three-dimensional is a visual effect that gives us the sensation of volume of objects. When we talk about volume effect that means that the figure has definition of height, width and especially depth. Three-dimensional is then the effect of depth.
Sculpture is itself a three-dimensional art, as depth is already attained naturally at the moment the form is created and the structure is modeled. But in painting and drawing, the depth effect can be achieved by the use of shading techniques (light and shadow effects), as well as geometric studies of shape and perspective techniques.
With my works 3Dimension I use a mix of techniques, evolving cutting pieces of wood (or plastic, or glass) and painting amongst others. The result are innovative objects of art with an optical illusion effect and very decorative.
Some of my three dimension artworks you can see here.