Mostly they are going to be computational geometry related, when put in the order of their priorities,
1. (Priority 1) Investigation into Triangularisation methods and the technologies they depend on
2. (Priority 2) 2D/3D shape relationship determination, such as whether two polygons intersect or overlap
3. (Priority 2) Spatial Indexing and Computational Geometry
4. (Priority 3) Not sure if it should be grouped with Spatial Indexing as well, it's a topic more specific to data structures for storing spatial objects so they can be easily queried
This topic should better be investigated in conjunction with spatial indexing as they are highly correlated.
(... more items are to be added as the study goes)