If we have low resolution geometry or a highly specular object then we will need more photographs to produce high quality synthetic images. If we have many photographs it will be beneficial to arrange them in a regular pattern to make rendering more efficient. The light field (or lumigraph) uses photographs placed on a regular grid. If the resolution is high enough then synthetic images can be reconstructed without using any geometry at all, but the Lumigraph paper (Gortler et al) described how to use geoemtry to increase the quality of the rendering.