Generating tiles/blocks around player

Hey Developers

I am currenly working a project which involves some sort of cube generation. My issue comes when generating these cubes. As help, I've linked to a "Roblox gamemode" which has the system/feautre I'm looking for. As the following video shows the system have several features

• Starting of by generating cube surface (so that only the surface is generated)
  
  
• Then by mining down, the system knows where the missing block should go and creates a random block in that current spot, but doesn't overlap the excisting ones.
  
  
• Third, the system then makes 5 blocks/cubes around the player when the player is mining down, so that their mining path is there, but the cubes always surround the player by 5 blocks.
  
  

I've tried looking into different solutions, but cannot figure out a way, that isn't laggy...

Thanks in advance!!

 

Check out any one of the hundreds of "how to make minecraft in Unity" types of Youtube videos... I imagine they would contain enough discussion to make this game as well, which as far as I can tell from the video above is just a simple single mechanic of minecraft.

 

Hey Man, thx for the fast reply!

Sadly Minecraft doesn't do as same as the video shown above. Minecraft load certains chunks, where we want to make the blocks generating as you go (as shown above)