Decisions, decisions, decisions.
High poly bake pros:
- Lighting accuracy.
- More control over details.
- Accurate mapping over geometry. Wear and dirt can be put exactly where they'd be making rocks more convincing.
- Impressive rock structures. Limited by imagination and sculpting talent.
- More maps. Each model has specific maps to each model. If you want to keep it seamless and looking good.
- Less texture resolution. A 2048 color map stretched over a larger model will result in a more blurry texture. 4096 and other tricks can be used but it's tricky.
- Takes more time. Sculpting, baking, uv mapping, making a specific material, and fixing seams all add up.
Blended tiled textures pros:
- Fast. Impressive results in a fraction of the time once materials are set up.
- Seamless for main cave structure.
- Blending multiple maps creates good variety.
- Good texture resolution. Tiling factor can be raised or lowered.
- Mapping over geometry. The big one. Basically the maps wont fit perfectly over the mesh. This can be faked by adding more geometry and adjusting the geometry to fit the textures, but this method is imperfect.
- Less possible variety unless using too many polygons. You could make an impressive pillar with this method, but in order for it to compete with the other method you'd have to use more geometry.
You can see the results of my modeled rock formation below. I also made a crystal, crystal material, and puddle decal too.