This is like the imposter technique of Maciel and Shirley, but the imposters are generated dynamically. Our technique differs in that we compute the 2D image warp directly, instead of using the 2D warp induced by a 3D quad. This allows us to handle dynamic objects. We also factor shading. Composition architectures such as PixelFlow and the Address Recalculation Pipeline break the rendering into sprites with Z per pixel.
Z values are difficult to interpolate and compress.
Z values are expensive to store and transmit. And finally, Z values are redundant when used solely to determine a layering order, which is important for antialiasing. Our approach avoids the z overhead. Regan observes that not all objects need updating at the display rate, and factors globally across object sets requiring a common update rate. Our scheme factors over geometric objects and shading model terms, and accounts for relative motion between dynamic objects.