Santos, TiagoFerreira, AlfredoDias, FilipeFonseca, Manuel J.Christine Alvarado and Marie-Paule Cani2014-01-282014-01-282008978-3-905674-07-11812-3503https://doi.org/10.2312/SBM/SBM08/089-096In this paper we describe a system to create LEGO models using sketches. Although there are a few applications to create LEGO models, they are difficult to use, mainly due to the searching and manipulation mechanisms that they (do not) offer. Here, we propose a sketch based approach, where users can easily insert parts, by specifying their dimensions through sketches and the system suggests a list of possible parts. To help with the modeling and the manipulation we also developed a constraint based mechanism, which keeps parts connected, performs snapto- grid and detects collisions. Experimental tests with users revealed that our approach is easier and faster to use than a conventional application, such as LeoCAD.Categories and Subject Descriptors (according to ACM CCS): H.3.3 [Information Storage and Retrieval]: Information Search and Retrieval H.5.2 [Information Interfaces and Presentation]: User Interfaces