Detail-in-context terrain displacement algorithm with optimizations

A system for generating a presentation of a region-of-interest in a terrain data representation for display on a display screen, the system comprising:

• a processor coupled to the display screen;
• and,
• modules executed by the processor, the modules including:
• a module for translating each point of the representation within a lens bounds to a rotated plane being normal to a vector defined by a position for the region-of-interest with respect to a base plane for the representation and an apex above the base plane, the lens bounds defining a shoulder region at least partially surrounding a focal bounds defining a focal region in which the position is located, each point having a respective height above the base plane;
• a module for displacing each translated point from the rotated plane by a function of the respective height and a magnification for the focal region, the magnification varying across the shoulder region in accordance with a drop-off function;
• a module for rotating each displaced point toward a viewpoint for the region-of-interest to maintain visibility of each displaced point and each point of the data representation beyond the lens bounds when viewed from the viewpoint;
• and,
• a module for adjusting each rotated point corresponding to the shoulder region to provide a smooth transition to the data representation beyond the lens bounds.