Frame Sequential Interpolation for Discrete Level-of-Detail Rendering

In this paper we present a method for automatic interpolation between adjacent discrete levels of detail to achieve smooth LOD changes in image space. We achieve this by breaking the problem into two passes: We render the two LOD levels individually and combine them in a separate pass afterwards. The interpolation is formulated in a way that only one level has to be updated per frame and the other can be reused from the previous frame, thereby causing roughly the same render cost as with simple non interpolated discrete LOD rendering, only incurring the slight overhead of the final combination pass. Additionally we describe customized interpolation schemes using visibility textures. The method was designed with the ease of integration into existing engines in mind. It requires neither sorting nor blending of objects, nor does it introduce any constrains in the LOD used. The LODs can be coplanar, alpha masked, animated, impostors, and intersecting, while still interpolating smoothly.