In this paper, we propose a sketch-based editable polycube mapping method that, given a general mesh and a simple polycube that coarsely resembles the shape of the object, plus sketched features indicating relevant correspondences between the two, provides a uniform, regular, and user-controllable quads-only mesh that can be used as a basis structure for subdivision. Large scale models with complex geometry and topology can be processed efficiently with simple, intuitive operations. We show that the simple, intuitive nature of the polycube map is a substantial advantage from the point of view of the interface by demonstrating a series of applications, including kit-basing, shape morphing, painting over the parameterization domain, and GPU-friendly tessellated subdivision displacement, where the user is also able to control the number of patches in the base mesh by the construction of the base polycube.

Interactive Applications for Sketch-Based Editable Polycube Map

Representation and rendering of volumetric mesostructure using texture mapping can potentially allow the display of highly detailed, animated surfaces at a low performance cost. Given the need for consistently more detailed and dynamic worlds rendered in real-time, volumetric texture mapping now becomes an area of great importance. In this survey, we review the developments of algorithms and techniques for representing volumetric mesostructure as texture-mapped detail. Our goal is to provide researchers with an overview of novel contributions to volumetric texture mapping as a starting point for further research and developers with a comparative review of techniques, giving insight into which methods would be fitting for particular tasks. We start by defining the scope of our domain and provide background information regarding mesostructure and volumetric texture mapping. Existing techniques are assessed in terms of content representation and storage as well as quality and performance of parameterization and rendering. Finally, we provide insights to the field and opportunities for research directions in terms of real-time volumetric texture-mapped surfaces under deformation.

Survey of texture mapping techniques for representing and rendering volumetric mesostructure

Mapping textures to complex objects is a non-trivial task. It is often desirable or even necessary to map separate textures to different parts of an object, but it may be difficult to obtain high-quality texture filtering across the seams where textures meet. Existing real-time methods either require significant amounts of memory, prohibit use of wide texture filters, or have a high complexity. In this paper, we present a new method for sampling textures which is surprisingly simple, does not require padding, and results in high image quality. The method discards filter taps that extend beyond the texture boundary and relies on multisample antialiasing in order to produce good image quality. Our method is suitable for real-time implementations of rectangular-chart-based assets, such as per-patch texturing (e.g. Ptex).

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Avoiding Texture Seams by Discarding Filter Taps

We introduce a method to pack Ptex per-face texture data that is both space-efficient and hardware-friendly. Recently presented real-time implementations of Ptex have been wasteful with space and required a storage cost many times higher than the size of the original texture data. Our method packs multiple levels of Ptex data together, and requires only around 8% increase in storage for our test textures. Additionally, because of efficient data packing, our method wastes less space than a typical texture atlas, which requires buffer regions to be added between the separate charts within the texture.

/pdf/a-space-efficient-and-hardware-friendly-implementation-of-12zz098dg6.pdf

A space-efficient and hardware-friendly implementation of Ptex

Various embodiments provide for a new texture address mode that excludes any texture filter taps (i.e. coordinates) that fall outside the texture domain from the filtering process. Taps outside a texture domain are not considered in one embodiment. Also, various embodiments provide flexibility as to the texture coordinate locations t i and values of weights w i . The tap weight can be modified as a function of tap location and in particular whether a tap is within a texture.

Texture Address Mode Discarding Filter Taps

Texture unwrapping is a nearly ubiquitous step in texture mapping, and serves two important purposes: (1) it indicates where to sample texture across each face and (2) it allows artistic freedom to "trade" texels from low importance areas to high importance areas. Unfortunately, texture unwrapping is time-consuming and automated tools generally produce inferior results to those of a skilled artist. Additionally, even the best unwraps suffer from seams, which cause lighting discontinuities at best and surface discontinuities at worst.

Per-face texture mapping for real-time rendering

A color-correct alpha blending texture filter and a method of texture filtering. One embodiment of the color-correct alpha blending texture filter includes: (1) an alpha blender configured to receive a post-multiplied pixel color and convert to a pre-multiplied pixel color, and (2) a filter configured to apply texture filtering to the plurality of pixels based on pre-multiplied pixel colors.

John McDonald

Papers

Per-face texture mapping for real-time rendering

Color-correct alpha blending texture filter and method of use thereof