Back to results
US 8,803,880 B2Granted
Image-based lighting simulation for objects
AssigneePeking University
InventorsBingfeng Zhou, Jie Feng
Life of this patent
Estimating the term…
Abstract
This disclosure relates to simulating the light-reflective condition of an object when situated in a given environment. A spatial irradiance mapping of the environment may be obtained, from which a series of directional incidence light sources are determined. The reflective qualities of the object may be modeled as a bi-directional reflection distribution function to be applied to directional incidence light sources. The spatial irradiance mapping and/or bi-directional reflection distribution function may be obtained according to image-based techniques.
Claims16
A method, comprising:
- determining a directional incidence light source, with respect to a given point of a lighting environment, that is associated with a respective intensity, the determining comprises:
- generating a mapping of spatial irradiance distribution surrounding a given point of a lighting environment,
- stitching the mapping into a spherical panorama from a series of images of the lighting environment in a plurality of shooting directions from the given point,
- determining a salient light source represented in the mapping by executing an importance sampling algorithm, and
- projecting the determined salient light source from the spherical panorama onto a self-enclosed spherical spatial surface surrounding the given point in the lighting environment to determine the directional incidence light source on the self-enclosed spatial surface,
- wherein the directional incident light source's direction is towards the given point, and the lighting environment represents an area surrounding a real-world location;
- utilizing at least one gray value associated with the determined salient light source in the mapping to obtain the respective intensity for the incidence directional light source;
- generating an image of an object situated at the given point in the lighting environment from a viewing direction by applying a bi-directional reflection distribution function of the object on the respective intensity of the directional incidence light source;
- and
- outputting the generated image.
7 more elements
An apparatus, comprising:
- a computer processor programmed to:
- determine a directional incidence light source with respect to a given point of a lighting environment, the directional incidence light source associated with a respective intensity, and
- generate an image representing an object situated at the given point in the lighting environment from a viewing direction by applying a bi-directional reflection distribution function of the object on the respective intensity of the directional incidence light source;
- and
- a device configured to output the generated image, wherein the computer processor determines the directional incidence light source by:
- generating a mapping of spatial irradiance distribution surrounding the given point of the lighting environment,
- stitching the mapping into a spherical panorama from a series of images of the lighting environment in a plurality of shooting directions from the given point,
- determining a preset number of salient light sources represented in the mapping based on saliency values associated with salient light sources by executing an importance sampling algorithm,
- projecting the determined salient light sources from the spherical panorama onto a self-enclosed spherical spatial surface surrounding the given point in the lighting environment to obtain directional incidence light sources on the surface, based on the mapping,
- wherein the directional incident light sources' directions are towards the given point, and the lighting environment represents an area surrounding a real-world location, and utilizing at least one gray value associated with the determined salient light sources in the mapping to obtain respective intensities for the incidence directional light sources.
7 more elements
Dependencies are inferred from the claim text.