US 11,657,562 B2
Utilizing hemispherical clamping for importance sampling of image-based light to render a virtual environment
Xin Sun, Sunnyvale, CA (US); Milos Hasan, Oakland, CA (US); and Nathan Carr, San Jose, CA (US)
Assigned to Adobe Inc., San Jose, CA (US)
Filed by Adobe Inc., San Jose, CA (US)
Filed on Apr. 19, 2021, as Appl. No. 17/233,910.
Prior Publication US 2022/0335677 A1, Oct. 20, 2022
Int. Cl. G06T 15/06 (2011.01); G06T 7/536 (2017.01); G06T 15/00 (2011.01); G06T 1/20 (2006.01); G06T 7/507 (2017.01)
CPC G06T 15/06 (2013.01) [G06T 1/20 (2013.01); G06T 7/507 (2017.01); G06T 7/536 (2017.01); G06T 15/005 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A non-transitory computer-readable storage medium comprising instructions that, when executed by at least one processor, cause a computing device to:
sample, within a virtual environment comprising an image-based lighting (IBL) image and a virtual object, a first ray direction intersecting a first surface point of the virtual object and a second ray direction intersecting a second surface point of the virtual object;
utilize a first shading normal direction of the first surface point to determine a first hemispherical sampling function that limits sampling of the IBL image to a first hemispherical region corresponding to the first surface point of the virtual object, wherein the first hemispherical sampling function comprises a first probability distribution of sampling pixels of the IBL image within the first hemispherical region;
utilize a second shading normal direction of the second surface point to determine a second hemispherical sampling function that limits sampling of the IBL image to a second hemispherical region corresponding to the second surface point of the virtual object, wherein the second hemispherical sampling function comprises a second probability distribution of sampling pixels of the IBL image within the second hemispherical region;
sample, from within the first hemispherical region, a third ray direction between the first surface point of the virtual object and the IBL image utilizing the first hemispherical sampling function;
sample, from within the second hemispherical region, a fourth ray direction between the second surface point of the virtual object and the IBL image utilizing the second hemispherical sampling function; and
generate a digital image of the virtual environment from a camera perspective utilizing the first ray direction, the second ray direction, the third ray direction, and the fourth ray direction.