| 主权项 |
1. A computer-implemented method of presenting a camera viewpoint of a three-dimensional surface of a body within a two-dimensional viewport that is rendered on one or more computing devices, the body surface is defined by data of a three-dimensional coordinate system having x, y, and z axes, wherein the body includes a North pole and a South pole, a spin-axis that extends through a center of the body generally along the z-axis, and a swing-axis that extends generally along the x-axis through the center of the body perpendicular to the spin-axis and parallel to a plane defined by the map viewport, the method comprising:
rendering, by the one or more computing devices, a display of the body in the viewport using the three-dimensional coordinate system data; causing, by the one or more computing devices, the rendered body to move within the viewport between a current point (p0) on the body surface and a desired map point (pT) on the body surface using the three-dimensional coordinate system data by:
determining, by the one or more computing devices, an intermediate point (pM/pM′);determining, by the one or more computing devices, a spin-axis angle of revolution around the spin-axis between the current point and the intermediate point around a first body circle;determining, by the one or more computing devices, a swing-axis angle of revolution around the swing-axis between the intermediate point and the desired point around a second body circle; andmoving, by the one or more computing devices, the rendered body within the viewport along the determined spin-axis angle of revolution and the determined swing-axis angle of revolution; wherein moving the body within the viewport between the current point and the desired point does not change an orientation of the North pole of the rendered body within the viewport; and wherein the intermediate point comprises a point on the body at which the first body circle and the second body circle intersect. |
