In this paper we consider the problem of finding three-dimensional orthogonal drawings of maximum degree six graphs from the computational complexity perspective. We introduce the 3SAT reduction framework which can be used to prove the NP-hardness of finding three-dimensional orthogonal drawings with specific constraints. By using the framework we show that, given a three-dimensional orthogonal...

Humans use sketches drawn on paper, on a computer, or via hand gestures in the air as part of their communications. To recognize shapes in sketches, most existing work focuses on offline (post-drawing) recognition methods, trained on large sets of examples which serve as a plan library for the recognition method. These methods do not allow on-line recognition, and require a very large library (...

deep drawing of cylindrical shapes with high limiting drawing ratio (ldr) values is relatively difficult. annealing is a further operation, which in turn adds costs and consumes significantly time to the forming process. in the present work, cylindrical cups from brass sheet were made with only limited anneal during few steps, but having ldr of 9 that is about 2 times higher than previous works...

Haptic perception of shape is based on kinesthetic and tactile information synthesized across space and time. We studied this process by having subjects move along the edges of multisided shapes and then remember and reproduce the shapes. With eyes closed, subjects moved a robot manipulandum whose force field was programmed to simulate a quadrilateral boundary in a horizontal plane. When subjec...

Sketching is a natural modality of human-computer interaction for a variety of tasks, including, conceptual design. Our goal is to make drawing on a computer, as close as possible to drawing on a piece of paper, by placing as few constraints on the user as possible, while still enabling computer recognition of the hand-drawn shapes. Systems should include the ability to draw shapes in any order...

Ruled surface design and its applications are widely used in CAGD (Computer Aided Geometric Design) and industrial areas. The hyperbolic paraboloid, the cylinder, the cone, and the hyperboloid are ruled surfaces with particular shapes. In this paper, dual space drawing methods for these particular ruled surfaces are proposed. The underlying principles of these methods are the applications, exte...