Just added a video of my Unity3D test app “Possible Minecraft with Hexagon Blocks” to the youtube channel.

Watch it here: https://www.youtube.com/watch?v=Dq7Uxqk5Jks

It uses a concept similar to my Geometry Shader. In this version, only one ‘place holder’ vertex per block is sent to the gfx card (or discarded if block not visible). Then, the rest is built by the shader.
As there is no ‘full geometry’ available to the program (for e.g. raycasting), the block selection and movement calculations were done by custom math (not using Unity built-in raycast or physics). World size for this test is at fixed 128x128x32 blocks, with a map chunk size of 8x8x8.

Finally, I realized that building with hextiles isn’t as fun as using cubes. So, didn’t follow that route any further…