  We propose an image warping-based remote rendering technique for volumes that
decouples the rendering and display phases. Our work builds on prior work that
samples the volume on the client using ray casting and reconstructs a z-value
based on some heuristic. The color and depth buffer are then sent to the client
that reuses this depth image as a stand-in for subsequent frames by warping it
according to the current camera position until new data was received from the
server. We augment that method by implementing the client renderer using ray
tracing. By representing the pixel contributions as spheres, this allows us to
effectively vary their footprint based on the distance to the viewer, which we
find to give better results than point-based rasterization when applied to
volumetric data sets.
