First I'm going to create the ground mesh. It is not a height map. It has different textures and lots of vertices. I need to group them by texture and create the appropriate index buffers for each. I'm also going to create a special quad tree of index buffer parts to the same vertex buffer. The ground parts will be culled that are outside the camera frustum. This trick needs proper management to be quick to build and quick to render with the fewest draw calls possible.
I need to discover how to create vertex and index buffers. I will also need axis aligned bounding boxes and camera frustum intersection. I hope these are all supported in OpenTK.
I will also need to load textures and a proper shader for the ground.