Constructing Brick Sculptures from Pixel Art

Pacific Graphics 2015

Ming-Hsun Kuo1

You-En Lin1

Hung-Kuo Chu1

Ruen-Rone Lee1

Yong-Liang Yang2

1National Tsing-Hua University 2University of Bath


LEGO ®, a popular brick-based toy construction system, provides an affordable and convenient way of fabricating geometric shapes. However, building arbitrary shapes using LEGO bricks with restrictive colors and sizes is not trivial. It requires careful design process to produce appealing, stable and constructable brick sculptures. In this work, we investigate the novel problem of constructing brick sculptures from pixel art images. In contrast to previous efforts that focus on 3D models, pixel art contains rich visual contents for generating engaging LEGO designs. On the other hand, the characteristics of pixel art and corresponding brick sculpture pose new challenges to the design process. We present PIXEL2BRICK, a novel computational framework to automatically construct brick sculptures from pixel art. This is based on implementing a set of design guidelines concerning the visual quality as well as the structural stability of built sculptures. We demonstrate the effectiveness of our framework with various brick sculptures (both real and virtual) generated from a variety of pixel art images. Experimental results show that our framework is efficient and gains significant improvements over state-of-the-arts.



We present a computational design framework to construct brick sculptures from pixel art images. Given 2D shapes represented by pixel arts (column 1), our framework optimizes the geometry and color information of the shape (column 2), together with the brick layout (column 3), resulting in appealing, stable, and balanced LEGO brick sculptures that can be built in practice (column 4) (Input images: “Pikachu” © Pokémon Ltd, “Megaman” © Capcom Co., Ltd).
Overview: (a) Given an input pixel art image, the system (b) applies image deformation to optimize the state of equilibrium (the original shape is shaded in light red); (c) adapts pixels’ color to standard LEGO color palette; (d) performs pixel level operations to resolve disconnected parts (modified pixels are highlighted in red); and (e) composes each layer using legal LEGO bricks to obtain the final brick sculpture (Input image: “Zapdos” © Pokémon Ltd).
Our framework can generate plausible LEGO brick sculptures from a large variety of pixel art images (see also supplemental material). (Top row) The input pixel art images. (Middle row) The balanced and color remapped 2D shapes. Note that three examples on the right are adjusted to keep balanced by expanding supporting lines (Pikachu and Hulk) or adding supporting strut (Saber). (Bottom row) The final brick sculptures (Input images: “Dragon” and “Hydra” © Heavy Cat Multimedia Ltd., “Popeye” © King Features Syndicate, Inc., “Spaceship” © Asmir Rogo, “Stone Gargoyle” © umrae, “Pikachu” © Pokémon Ltd, “Hulk” © Marvel Worldwide Inc., “Saber” © Manning Leonard Krull).




We are grateful to the anonymous reviewers for their comments and suggestions; and Ying-Miao Kuo for assisting the video production. The work was supported in part by the Ministry of Science and Technology of Taiwan (102-2221-E-007-055-MY3, 103-2221-E-007-065-MY3, and 104-2220-E-007-016), University of Bath startup fund, and EPSRC Grant EP/M023281/1.


  title = {PIXEL2BRICK: Constructing Brick Sculptures from Pixel Art},
  author = {Ming-Hsun Kuo and You-En Lin and Hung-Kuo Chu and Ruen-Rone Lee and Yong-Liang Yang},
  journal = {Computer Graphics Forum (Pacific Graphics 2015)},
  volume = {34},
  issue = {7},
  year = {2015}


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