Solving the Shadow Art Problem

Yunjoo Park, Zhonghua Xi, and Jyh-Ming Lien


Creating shadow art has always been labor intensive and time consuming through trial-and-error methods. In this work, we look into the problem of placing objects in 3D space so they collectively cast desired shadow. Such an installation consisting of carefully arranged objects and shadows is usually known as shadow art.

The shadow art problem is a variant of the packing and covering problems. The main objective in solving the 2.5 shadow art problem is to place the 3D light blockers on a 2D plane so that the their shadows can cover the target stencil image while ensuring that the light blockers do not overlap.

Inputs of the proposed method (see the figure below): (a) Target shadow. (b) Light blockers including English alphabets (horizontal) and numerical digits (vertical). (c) The grey area indicates allowable locations of the shadows cast by the light blockers.

Method overview in Figures (d)–(g) below. The orange areas in (d) and (e) indicate uncovered regions of the target shadow.

pipe line


Coming soon.


3D printed results and shadows obtained under different light sources

Correct shadowFunny shadow
Projector light imageimage
Sunlight imageimage

Additional results



Yunjoo Park and Jyh-Ming Lien. “Fabricate 2.5D Shadow Art Sculpture”, HYPERSEEING, the Publication of the international Society of Arts, Mathematics and Architecture, Summer 2016 issue. (Featured as the front cover image) Also in Proceedings of SMI’2016 Fabrication and Sculpting Event (FASE), June 2016
Download paper in pdf format.


Related Links

Computer Science @ George Mason University