Viewshed videos provide a quick comparison of multiple Viewshed images to show the increased sign visibility (indicated in green) based on sign height
NeRF, or Neural Radiance Field, is a fully connected neural network that can generate 3D views of scenes based on a partial set of 2D images. The NeRF below of the 400/53 intersection was made with video taken with my drone
This is a Viewshed comparison
This is a NeRF