1. A process for producing a perspective image based on height field data, said image having a foreground and a background, said process comprising the steps of: establishing a centered viewpoint for said perspective image; sampling said height field data to generate a radial form height field, said height field having a relatively greater level of detail for said foreground and a relatively lesser level of detail for said background, said sampling step including: defining rays extending radially from said centered viewpoint in model space, said rays being substantially parallel in image space; and sampling said height field data at selected locations along said rays in model space to provide height samples, said locations forming vertices of substantially square trapezoidal shapes in model space, said shapes increasing in size with increasing radial distance from said centered viewpoint in model space, but being substantially uniform in image space; processing picture elements in relation to said viewpoint based on said radial form height field to provide perspective display data; and driving a display in accordance with said perspective display data to provide said perspective image.