Abstract: The present soft shadowing technique pre-computes visibility of blockers using a log of a spherical harmonic visibility function. These logs can then be accumulated and exponentiated in real-time to yield the product visibility vector over all the blockers. The product visibility vector is combined with the light intensity and surface reflectance to determine shading at a receiver point in a computer-generated scene.

Abstract: A computer implemented method for generating a representation of structure for use in rendering a synthesized image is provided. The representation is a view-dependent displacement mapping that represents displacements along a viewing direction. This view dependency allows the representation to be used to determine self shadows as well as shading, occlusion and silhouettes when used during rendering for synthesis.

Abstract: Representing quasi-homogenous materials is described. In one aspect, quasi-homogenous materials are modeled to generate a material model of a physical sample. The material model identifies how light is scattered by the quasi-homogenous materials. The material model, independent of an object model of the physical sample, provides information that is useful to texture surfaces of arbitrary types and sizes of mesh models (e.g., representing the physical sample or other objects) with the quasi-homogenous materials.

Abstract: A “mesostructure renderer” uses pre-computed multi-dimensional “generalized displacement maps” (GDM) to provide real-time rendering of general non-height-field mesostructures on both open and closed surfaces of arbitrary geometry. In general, the GDM represents the distance to solid mesostructure along any ray cast from any point within a volumetric sample. Given the pre-computed GDM, the mesostructure renderer then computes mesostructure visibility jointly in object space and texture space, thereby enabling both control of texture distortion and efficient computation of texture coordinates and shadowing. Further, in one embodiment, the mesostructure renderer uses the GDM to render mesostructures with either local or global illumination as a per-pixel process using conventional computer graphics hardware to accelerate the real-time rendering of the mesostructures.

Abstract: Encoded HDR textures are described. In one aspect, a HDR image comprised is preprocessed such that HDR information is represented in a single color channel. The preprocessed image is quantized in view of two luminance ranges to retain HDR in the single color channel. Each block of quantized channel information is then encoded across two textures (encoded HDR textures). Specifically, when encoding a block of the quantized information, pixels in a first range of the two luminance ranges are put into a color channel associated with a first texture. Additionally, pixels in a second range of the two luminance ranges are stored into a color channel associated with a second texture.

Abstract: A method and system for implementing capturing and rendering geometric details for mesostructure surfaces is described herein. A mesostructure distance function is defined as a function of a given reference point and a given viewing direction. A distance from a reference point to a mesostructure surface point along a viewing direction is measured using the mesostructure distance function. This distance is used to determine the visibility of mesostructure surface for rendering silhouettes. The lighting visibility of the mesostructure surface point may also be determined and used for determining whether the mesostructure surface point is in shadow. This determination may then be used for rendering shadow silhouettes.

Abstract: A “mesostructure renderer” uses pre-computed multi-dimensional “generalized displacement maps” (GDM) to provide real-time rendering of general non-height-field mesostructures on both open and closed surfaces of arbitrary geometry. In general, the GDM represents the distance to solid mesostructure along any ray cast from any point within a volumetric sample. Given the pre-computed GDM, the mesostructure renderer then computes mesostructure visibility jointly in object space and texture space, thereby enabling both control of texture distortion and efficient computation of texture coordinates and shadowing. Further, in one embodiment, the mesostructure renderer uses the GDM to render mesostructures with either local or global illumination as a per-pixel process using conventional computer graphics hardware to accelerate the real-time rendering of the mesostructures.

Abstract: Large mesh deformation using the volumetric graph Laplacian is described. In one aspect, information is received from a user, wherein the information indicates how an original mesh is to be deformed. The original mesh is then deformed based on the information and application of a volumetric differential operator to a volumetric graph generated from the original mesh.

Abstract: Texture montage is described. In one aspect, feature correspondences are received. The feature correspondences map at least one region on a 3-D mesh to at least one region on an image of one or more images. Each of the images provides texture information. An atlas of texture patches is created based on the feature correspondences. The atlas of texture patches provides for rendering texture from the images onto the 3-D mesh.

Abstract: A shell radiance texture function (SRTF) is defined to record an outgoing radiance from a base volume of an object to be rendered. Using the SRTF, radiance values are precomputed and stored for the base volume. The object is rendered using the precomputed radiance values.

Abstract: The present surface detail rendering technique provides an efficient technique for applying a mesostructure to a macrostructure for an object that minimizes the amount of memory required for pre-computed data. A leap texture is pre-computed for a mesostructure by classifying each voxel in the mesostructure geometry and assigning a value in the leap texture based upon the classification. The value in the leap texture represents a distance to jump along a ray cast in any view direction when a model is decorated with the mesostructure geometry.

Abstract: Knitwear modeling is disclosed. A macrostructure corresponding to a three-dimensional object is generated, based on a stitch pattern and optionally a color pattern. Yarn microstructure is generated and applied to the macrostructure to yield a knitwear model. The stitch positions of the macrostructure can be perturbed to achieve stitch position irregularities. The fluffiness of the yarn microstructure can be controlled. In an alternative embodiment, a two-dimensional knitwear texture is generated, which can then be mapped to a three-dimensional object to yield a knitwear model.

Abstract: A system and process for determining the vignetting function of an image and using the function to correct for the vignetting is presented. The image can be any arbitrary image and no other images are required. The system and process is designed to handle both textured and untextured segments in order to maximize the use of available information. To extract vignetting information from an image, segmentation techniques are employed that locate image segments with reliable data for vignetting estimation. Within each image segment, the system and process capitalizes on frequency characteristics and physical properties of vignetting to distinguish it from other sources of intensity variation. The vignetting data acquired from segments are weighted according to a presented reliability measure to promote robustness in estimation.

Abstract: A method of performing stretch-driven mesh parameterization. A method of performing stretch-driven mesh parameterization comprising, computing a spectral analysis to parameterize a mesh, and iterating a stretch optimization calculation to further optimize the initial parameterization.

Abstract: A system and process for reconstructing optimal texture maps from multiple views of a scene is described. In essence, this reconstruction is based on the optimal synthesis of textures from multiple sources. This is generally accomplished using basic image processing theory to derive the correct weights for blending the multiple views. Namely, the steps of reconstructing, warping, prefiltering, and resampling are followed in order to warp reference textures to a desired location, and to compute spatially-variant weights for optimal blending. These weights take into consideration the anisotropy in the texture projection and changes in sampling frequency due to foreshortening. The weights are combined and the computation of the optimal texture is treated as a restoration problem, which involves solving a linear system of equations.

Abstract: A computer implemented method for generating a representation of structure for use in rendering a synthesized image is provided. The representation is a view-dependent displacement mapping that represents displacements along a viewing direction. This view dependency allows the representation to be used to determine self shadows as well as shading, occlusion and silhouettes when used during rendering for synthesis.

Abstract: A “mesostructure renderer” uses pre-computed multi-dimensional “generalized displacement maps” (GDM) to provide real-time rendering of general non-height-field mesostructures on both open and closed surfaces of arbitrary geometry. In general, the GDM represents the distance to solid mesostructure along any ray cast from any point within a volumetric sample. Given the pre-computed GDM, the mesostructure renderer then computes mesostructure visibility jointly in object space and texture space, thereby enabling both control of texture distortion and efficient computation of texture coordinates and shadowing. Further, in one embodiment, the mesostructure renderer uses the GDM to render mesostructures with either local or global illumination as a per-pixel process using conventional computer graphics hardware to accelerate the real-time rendering of the mesostructures.

Abstract: Systems and methods are presented for real-time realistic river modeling. In one implementation, when provided with the physical features of a modeled terrain, the systems and methods described herein automatically determine a watercourse route in relation to the terrain and calculate river borders. The systems and methods then calculate a surface structure for the river between the borders and map texture coordinates to the surface structure. The systems and methods apply textures at the texture coordinates to provide an animated, view-dependent representation of wave geometries for the modeled water surface including reflection, refraction, and Fresnel effects.

Abstract: Rendering of a partially translucent object is performed using a set of parameter maps derived from data measuring reflectance and transmittance of light received at the surface of the partially translucent object. Data is captured from an actual object being modeled, rather than estimated based on internal structure and composition. Parameter maps relating albedo, thickness variation, and specular intensity and roughness are stored as textures to facilitate rendering. In addition, realistic illumination from high energy sources such as sunlight is effected by separating light into low frequency and high frequency components. Low frequency components are rendered by precomputed radiance transfer. High frequency components, which are not modeled well by precomputed radiance transfer, are modeled using a light visibility convolution integral to generate light visibility maps for positions of the high frequency light source.

Abstract: A method and system for efficient synthesis of photorealistic free-form knitwear, where a single cross-section of yarn serves as the basic primitive for modeling entire articles of knitwear. This primitive, called the lumislice, describes radiance from a yarn cross-section based on fine-level interactions, including occlusion, shadowing, and multiple scattering, among yarn fibers. By representing yarn as a sequence of identical but rotated cross-sections, the lumislice can effectively propagate local microstructure over arbitrary stitch patterns and knitwear shapes. This framework accommodates varying levels of detail and capitalizes on hardware-assisted transparency blending. To further enhance realism, a technique for generating soft shadows from yarn is also introduced.