My question today is there a way you can scan the inside of a cave to create an exact (or near to exact) replica of the caves geometry? I am familiar with a scanning item that will take x,y & z points from, lets say someones back in order to create the curvature of the spine. I just want to do that on a larger scale.
Are you talking about making a model of a real world cave? There are programs that can reconstruct 3D model from multiple photos, for example Agisoft PhotoScan, there are probably others but I am only familiar with this one. I am not sure that this would work well with a cave though, it requires photos of an object taken from many angles and cave walls may limit possible angles.
But, in my opinion, in case of a cave it might be easier to just model it by hand than doing 3D reconstruction, unless you need to match a real cave really closely.
The cave would need to be as near to the original as possible because it is for a preservation project. That is way I wanted to explore the option of scanning the caves surfaces to create the mesh of the cave.
Look into laser scanning, likethese folks offer.
Or you could just build a landscape, invert the normals and build your level inside it.