Rendering a sky veil on an avionic primary flight display

An avionic display software for an aircraft, the avionic display software comprising:

• a display device coupled to receive image rendering display commands and responsively display rendered images;
• a terrain data source to output terrain data representative of terrain in a field of view of a pilot of the aircraft;
• an avionic flight data source to output avionic data representative of an avionic state of the aircraft, including a roll angle thereof;
• and
• computing resources coupled to the terrain data source to receive terrain data therefrom, to the avionic flight data source to receive avionic data therefrom, and to the display device to supply image rendering display commands thereto based on the received terrain and avionic data;
• the avionic display software is executable by the computing resources to cause, when executed, the computing resources to become programmed to cause rendered images representative of an out-the-window view of the operator of the aircraft to be displayed by the display device;
• a rendered image comprises one or both of rendered terrain and rendered sky, which are representative of real-world terrain and sky outside of the aircraft and whose positions and orientations are dependent upon position and orientation of the aircraft relative thereto;
• a rendered image further comprises a rendered sky veil;
• the sky veil is an overlapping graphic representation rendered at least partially transparent in such a manner that (i) portions of the rendered sky veil that (eventually) overlap with the rendered sky are not discernable from the rendered sky, and (ii) the rendered terrain is viewable through transparent portions of the sky veil that overlap with the rendered terrain;
• wherein the sky veil is rendered as a band stationary in the rendered image during roll of the aircraft;
• and
• wherein the sky veil is rendered at least partially transparent along a width thereof such that a width of a transparent region of the sky veil depends on a roll angle of the aircraft;
• and
• wherein the transparent region is further rendered along the width of the sky veil in such a position as to be indicative of the direction of the sky.

An avionic display software for an aircraft, the avionic display software comprising:

• a display device coupled to receive image rendering display commands and responsively display rendered images;
• a terrain data source to output terrain data representative of terrain in a field of view of a pilot of the aircraft;
• an avionic flight data source to output avionic data representative of an avionic state of the aircraft, including a roll angle thereof;
• and
• computing resources coupled to the terrain data source to receive terrain data therefrom, to the avionic flight data source to receive avionic data therefrom, and to the display device to supply image rendering display commands thereto based on the received terrain and avionic data;
• the avionic display software is executable by the computing resources to cause, when executed, the computing resources to become programmed to cause rendered images representative of an out-the-window view of the operator of the aircraft to be displayed by the display device;
• a rendered image comprises one or both of rendered terrain and rendered sky, which are representative of real-world terrain and sky outside of the aircraft and whose positions and orientations are dependent upon position and orientation of the aircraft relative thereto;
• a rendered image further comprises a rendered sky veil;
• the sky veil is an overlapping graphic representation rendered at least partially transparent in such a manner that (i) portions of the rendered sky veil that (eventually) overlap with the rendered sky are not discernable from the rendered sky, and (ii) the rendered terrain is viewable through transparent portions of the sky veil that overlap with the rendered terrain;
• the sky veil is rendered as a band with a motion in the rendered image during roll of the aircraft as a function of a roll angle thereof;
• wherein the sky veil is rendered as a band comprising a plurality of parallel and spaced-apart sub-bands and the sky veil is rendered at least partially transparent along its height;
• and
• the rendered image further includes rendered flight-related information comprising a rendered zero pitch reference line, wherein the sky veil is rendered parallel to the rendered zero pitch reference line at a distance therefrom which is dependent on the roll angle of the aircraft;
• when the roll angle satisfies a first condition, the distance satisfies a first relation with the roll angle and wherein, when the roll angle satisfies a second condition, the distance satisfies a second relation with the roll angle;
• and
• when the distance satisfies the first relation with the roll angle, the distance increases proportionally with the roll angle and, when the distance satisfies the second relation with the roll angle, the distance decreases proportionally with the roll angle.