File:Polar view of Kerr BH.gif

English: This picture shows a black hole with a rotational parameter of 0.9 and a thin disk from the perspective of the distant observer. Over the different frames, the perspective on the black hole varies over 12 diferent polar angles between -90° and 90°. The disk is modeled as infinitely large and thin with a linear color gradient, that shows the distance of the disk from the black hole. This way, it is visualising the apparent disk curvature better than a realistic, heat-based color gradient. This picture is created using an inverse raytracer with 121x121 rays. The raytracer is numerically calculating the trajectories of light rays hitting the pixels in Kerr metric and checking if they have crossed the disk at some point. If this is the case, it stops ray calculation and colors the pixel according to the disk color gradient.