Non-homogeneous resizing of complex models

Abstract

Figure 1: Resizing a clock model (267 connected components): Standard non-uniform scale distorts the shape of parts of the model, e.g. the dial (b). Our approach resizes the clock in a more natural manner protecting its shape (c). (d) and (e) show part of the protective grid before and after resizing. AbstractResizing of 3D models can be very useful when creating new models or placing models inside different scenes. However, uniform scaling is limited in its applicability while straightforward nonuniform scaling can destroy features and lead to serious visual artifacts. Our goal is to define a method that protects model features and structures during resizing. We observe that typically, during scaling some parts of the models are more vulnerable than others, undergoing undesirable deformation. We automatically detect vulnerable regions and carry this information to a protective grid defined around the object, defining a vulnerability map. The 3D model is then resized by a space-deformation technique which scales the grid non-homogeneously while respecting this map. Using space-deformation allows processing of common models of man-made objects that consist of multiple components and contain non-manifold structures. We show that our technique resizes models while suppressing undesirable distortion, creating models that preserve the structure and features of the original ones.

Ergonomics-Inspired Reshaping and Exploration of Collections of Models

“…Shape deformation is a longstanding topic in geometry processing [20]. The shape deformation methods mainly fall into two classes: those that aim to preserve the shape's local properties, such as curvature, differential coordinates [21], [22], [23], and those that aim to preserve global structures, such as symmetry and inter-part relations [24], [25], [26]. Li et al [27] deform input man-made objects to make them amenable to stacking.…”

Design and fabrication by example

“…Kraevoy et al[2008] present a method for shape-aware resizing of man-made objects that can be non-uniformly scaled along three main axes. Our work is also related to the iWires system [Gal et al 2009], which preserves structural relationships during editing using constrained non-linear optimization.…”

Joint-aware manipulation of deformable models

“…Non-homogeneous resizing is needed to preserve important structure and features, such as circular shapes, of complex models consisting of multiple components [Kraevoy et al 2008]. A protective grid, or vulnerability map, is first constructed.…”

“…Our method addresses issues that are complementary to such resizing problems. Cylindrical and spherical joints between components, such as hinges and ball-and-socket joints, are automatically preserved by our joint-aware deformation, although for different underlying reasons than those proposed by Kraevoy et al[2008].…”

“…However, many 3D models, particularly those of man-made CAD objects, consist of multiple components. Recent years have seen considerable progress in making geometric deformations more content aware, such as material-aware mesh deformation [Popa et al 2006] and non-homogeneous resizing of complex models [Kraevoy et al 2008]. These methods acknowledge that complex models usually have multiple parts with different properties and features, which should be treated differently during manipulation.…”