US Patent 10546415 Point cloud proxy for physically-based volume rendering

Physically-based volume rendering produces pixels. By assigning depths to the pixels, a 3D point cloud is generated. For more rapid rendering, such as due to user interaction, the 3D point cloud rendering is a proxy to physically-based volume rendering. The rendering parameters for the desired image may be determined using the proxy, and then physically-based volume rendering is performed to obtain the desired image.