Sketching is an established part of engineering culture. Sketches assist product designers during... more Sketching is an established part of engineering culture. Sketches assist product designers during the creative stages of design and help them to develop inventions. Paper-and-pencil sketching is highly useful but lacks functionalities, mainly because it is disconnected from the rest of the (computer-aided) design process. However, CAS tools are not yet as usable as paper-and-pencil, although they provide full integration with the subsequent phases of the design processes (CAD, CAE, CAM, etc.) and other interesting functionalities. We ...
In this tutorial, we describe the state of the art of sketch input of engineering solid models. T... more In this tutorial, we describe the state of the art of sketch input of engineering solid models. The tutorial is in four parts. In the first part, we show how sketching has historically been an important aspect of engineering culture,and remains a useful tool in the early design phase as it has been demonstrated that sketching enhances creativity.We discuss and classify various current approaches to computer interpretation of sketches.We introduce the problem of deducing design intent, which we understand as a mix of geometry, psychology and engineering, and note how no existing approach to interpretation of sketches has considered the explicit capture of design intent from the input sketch. In the second and third parts, we present our selection of the most important algorithms currently used for interpreting wireframe drawings (part two) and natural line drawings (part three) of engineering objects. In part two, the algorithms we look at are: for finding faces in wireframes; for inflating wireframes to 3D; and for processing rounds and fillets. In part three, we look at: line labelling; inflation to 2.5D; and deducing hidden topology. In part four, we discuss some of the most interesting open problems: making virtual paper and pencil more usable than actual paper and pencil; interpreting annotated engineering sketches; and creating assemblies from sketches.
International Journal of Shape Modeling, Jun 1, 2003
Labelling line drawings is a useful technique in several applications, including that of automate... more Labelling line drawings is a useful technique in several applications, including that of automated interpretation of line drawings as polyhedral solid objects. Algorithms exist which can in practice label line drawings of trihedral polyhedra correctly in low-order polynomial time. However, the restriction to trihedral polyhedra is too limiting for practical applications. We are primarily interested in interpreting line drawings of engineering objects, and many of these objects contain non-trihedral (usually tetrahedral) vertices. We therefore investigate ...
International Journal of Shape Modeling, Jun 1, 2001
The Clowes-Huffman catalogue for labelling line drawings of trihedral polyhedra is a well-establi... more The Clowes-Huffman catalogue for labelling line drawings of trihedral polyhedra is a well-established tool in computer vision. We currently use it in processing sketch input of solid models of engineering components. However, many such components also contain tetrahedral vertices. Thus, this paper presents a similar catalogue for tetrahedral polyhedra.
Sketching is an established part of engineering culture. Sketches assist product designers during... more Sketching is an established part of engineering culture. Sketches assist product designers during the creative stages of design and help them to develop inventions. Paper-and-pencil sketching is highly useful but lacks functionalities, mainly because it is disconnected from the rest of the (computer-aided) design process. However, CAS tools are not yet as usable as paper-and-pencil, although they provide full integration with the subsequent phases of the design processes (CAD, CAE, CAM, etc.) and other interesting functionalities. We ...
In this tutorial, we describe the state of the art of sketch input of engineering solid models. T... more In this tutorial, we describe the state of the art of sketch input of engineering solid models. The tutorial is in four parts. In the first part, we show how sketching has historically been an important aspect of engineering culture,and remains a useful tool in the early design phase as it has been demonstrated that sketching enhances creativity.We discuss and classify various current approaches to computer interpretation of sketches.We introduce the problem of deducing design intent, which we understand as a mix of geometry, psychology and engineering, and note how no existing approach to interpretation of sketches has considered the explicit capture of design intent from the input sketch. In the second and third parts, we present our selection of the most important algorithms currently used for interpreting wireframe drawings (part two) and natural line drawings (part three) of engineering objects. In part two, the algorithms we look at are: for finding faces in wireframes; for inflating wireframes to 3D; and for processing rounds and fillets. In part three, we look at: line labelling; inflation to 2.5D; and deducing hidden topology. In part four, we discuss some of the most interesting open problems: making virtual paper and pencil more usable than actual paper and pencil; interpreting annotated engineering sketches; and creating assemblies from sketches.
International Journal of Shape Modeling, Jun 1, 2003
Labelling line drawings is a useful technique in several applications, including that of automate... more Labelling line drawings is a useful technique in several applications, including that of automated interpretation of line drawings as polyhedral solid objects. Algorithms exist which can in practice label line drawings of trihedral polyhedra correctly in low-order polynomial time. However, the restriction to trihedral polyhedra is too limiting for practical applications. We are primarily interested in interpreting line drawings of engineering objects, and many of these objects contain non-trihedral (usually tetrahedral) vertices. We therefore investigate ...
International Journal of Shape Modeling, Jun 1, 2001
The Clowes-Huffman catalogue for labelling line drawings of trihedral polyhedra is a well-establi... more The Clowes-Huffman catalogue for labelling line drawings of trihedral polyhedra is a well-established tool in computer vision. We currently use it in processing sketch input of solid models of engineering components. However, many such components also contain tetrahedral vertices. Thus, this paper presents a similar catalogue for tetrahedral polyhedra.
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Papers by Peter Varley