A rendering technique for efficiently computing indoor scene illumination by reparametrizing directional light distributions relative to scene geometry.
Techniques for illuminating an indoor scene. A directional distribution associated with the indoor scene is received. The indoor scene has a first scene element and a first quadrilateral. The first scene element has a first shading point disposed thereon. The directional distribution is reparametrized such that the first quadrilateral as viewed from the first shading point corresponds to an axis-aligned rectangular region in the reparametrized directional distribution. The scene element is illuminated using one or more samples drawn from the shading point by performing importance sampling based on the reparametrized directional distribution.
BRIEF DESCRIPTION OF THE DRAWINGS(1) The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.(2) So that the manner in which theabove recited features presented in this disclosure can be understood in detail, a more particular description of the features, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings.(3) It is to be noted, however, that the appended drawings illustrate only typical embodiments presented in this disclosure and are therefore not to be considered limiting of its scope, for aspects presented in this disclosure may admit to other equally effective embodiments.(4) FIG. 1 is a block diagram illustrating a system for indoor scene illumination, according to one embodiment presented in this disclosure.(5) FIG. 2 depicts an indoor scene and associated environment maps showing visible regions from the indoor scene, according to one embodiment presented in this disclosure.(6) FIG. 3 illustrates a portal in a canonical reference frame centered on a shading point in the indoor scene, according to one embodiment presented in this disclosure.(7) FIG. 4 depicts rectified coordinates over a hemisphere of directions, an environment map resampled using the rectified coordinates, and a contour plot of a resulting determinant, acco
1. A computer-implemented method of illuminating an indoor scene, the computer-implemented method comprising: receiving a directional distribution associated with the indoor scene, the indoor scene having a first scene element and a first quadrilateral, the first scene element having disposed thereon a first shading point; reparametrizing the directional distribution such that the first quadrilateral as viewed from the first shading point corresponds to an axis-aligned rectangular region in the reparametrized directional distribution; drawing one or more samples from the shading point by performing importance sampling based on the reparametrized directional distribution using a single, summed-area table; and illuminating the first scene element using the one or more samples and by operation of one or more computer processors, whereafter the first scene element is output.
8. A non-transitory computer-readable medium containing a program which, when executed, performs an operation to illuminate an indoor scene, the operation comprising: receiving a directional distribution associatedwith the indoor scene, the indoor scene having a first scene element and a first quadrilateral, the first scene element having disposed thereon a first shading point; reparametrizing the directional distribution such that the first quadrilateral as viewed from the first shading point corresponds to an axis-aligned rectangular region in the reparametrized directional distribution; drawing one or more samples from the shading point by performing importance sampling based on the reparametrized directional distribution using a single, summed-area table; and illuminating the first scene element using the one or more samples and by operation of one or more computer processors when executing the program, whereafter the first scene element is output.
15. A computer-implemented method of illuminating an indoor scene using image-based lighting, the computer-implemented method comprising: receiving an environment map depicting a surrounding environment external to the indoor scene, theindoor scene having a first scene element and a first opening to the surrounding environment, the first scene element having disposed thereon a first shading point; defining a first portal through which a first region of the surrounding environment is visible to the first shading point, the first portal comprising a rectangular approximation of the first opening; reparametrizing the environment map such that the first region of the surrounding environment as viewed from the first shading point through the first portal corresponds to an axis-aligned rectangular region in the reparametrized environment map; determining a function of both the reparametrized environment map and a visibility map specifying visibility of the surrounding environment as viewed from the first shading point through the firstportal; drawing one or more samples from the shading point through the first portal by importance sampling the function of the reparametrized environment map and the visibility map using a single, summed-area table per portal; and illuminating the first scene element using the one or more samples and by operation of one or more computer processors, whereafter the first scene element is output.