Abstract

A method for anticipation and tracking eye movement for head tracked projectors which divides a projection surface into spherical triangles and uses interpolating calibration values stored at each vertex of the triangle. A calibration map is used that contains information about the relationship between the user's head orientation and where they are looking with their eyes at each calibration point. The projection surface is divided into spherical triangles which are searched to find the triangle which contain the user's interpolated view point by performing a dot product test between the interpolated view point and the unit normal vectors inside the three planes that make up the sides of the spherical triangle extended back to the eye point. When a dot product test fails for any side of the triangle the pointer is followed to the adjacent triangle where the test starts over. When the triangle is found that has the interpolated view point inside it, the selected triangle is divided into three sub-triangles. Then the area of the sub-triangles inside the selected triangle is computed. The areas of the sub-triangles are then used to find ratios of the sub-triangles' areas versus the selected spherical triangle area for weighting the calibration points stored with each vertex. Then the weighted calibrations are added to the values for the interpolated view point. This creates a calibrated view point where the head tracked projector is then pointed and the computer generated simulated image is projected.