This invention is a method for generating high-quality shadows with trapezoidal shadow maps. The method addresses the aliasing problem of standard shadow maps in a novel way: it approximates the camera frustum seen from the light’s view with a trapezoid to compute the shadow map for this trapezoidal area to achieve the goal of good resolution for objects within a focus region, without worsening the polygon offset problem. In addition, it efficiently computes trapezoids (independent of scene complexity) to address the so-called continuity problem where shadows appear and disappear. This problem occurs, in all recent approaches, when the shadow map quality changes drastically from frame to frame due to the change in eye’s view. On the whole, the proposed method is simple to implement without using complex data structures, and it maps well and executes efficiently in graphics hardware.

(An overview of the city rendered using TSM)

This technology has a wide range of applications:

1. Computer Games: generate quality shadow for computer games (such as PCs or Xbox games) to enhance the gaming experience.

2. Urban Planning Software: generate shadows on the fly for the different Sun’s positions in urban planning studies.

3. Visual Simulators: generate quality shadow for visual simulators to enhance the realism of training and simulation software.

4. Animation Software: generate real-time shadows (for previewing) of computer animation sequences

Proposed method has been implemented and tested. We are looking for collaborators /software companies to incorporate the method into their software/game systems.

1. High quality shadows are generated for all large as well as small, curved and sharp objects, and objects from near to far away from the light sources.

2. Shadows generated (for both dynamic and static objects) do not have the annoying flickering effect that existed in all previous approaches;

3. The method does not consume much computing resources.

(comparisons of shadows generated by BB(left),PSM (center), and TSM (right))

(A zoom from a distance on the shadows of the car port on the Mercedes; TSM on the right)