%0 Report %T Analytical calculation of the solid angle subtended by an arbitrarily positioned ellipsoid %+ Unity Technologies [San Francisco] %A Heitz, Eric %I Unity Technologies %8 2016-11-24 %D 2016 %K solid angle %K ellipsoid %Z Mathematics [math]/General Mathematics [math.GM]Reports %X We present a geometric method for computing an ellipse that subtends the same solid-angle domain as an arbitrarily positioned ellipsoid. With this method we can extend existing analytical solid-angle calculations of ellipses to ellipsoids. Our idea consists of applying a linear transformation on the ellipsoid such that it is transformed into a sphere from which a disk that covers the same solid-angle domain can be computed. We demonstrate that by applying the inverse linear transformation on this disk we obtain an ellipse that subtends the same solid-angle domain as the ellipsoid. We provide a MATLAB implementation of our algorithm and we validate it numerically. %G English %2 https://hal.science/hal-01402302v1/document %2 https://hal.science/hal-01402302v1/file/solidAngleEllipsoid.pdf %L hal-01402302 %U https://hal.science/hal-01402302