I've been working for a while on building 3D models, and now that I've scaled back I think the results are turning out pretty nice. I'm starting on the surface because it is so much easier to get equipment on location.
Made this model of a fire hydrant locally. I think it shows the potential for capturing formation is 3D models.https://skfb.ly/EozZ
I had originally started with LIDAR, but the processing for that is daunting. Then I moved to the Kinect which was a lot of fun, but my Xbox kinect isn't very portable for cave usage. Now I'm trying to build much smaller models of single formations and single rooms. I'm getting a lot more success with this.
I used an iPhone with 123d Catch to capture this model. The issue is that this requires good lighting and even lighting that doesn't change. I'm working on another set of equipment that should resolve that issue and capture models that are even better than this though.
Let me know what you think of the model as a starting point.