World craft terrain Editor

Implemented the simplest level of detail.

In the previous version of the editor, it is very easy to fix the crack. This version of the editor fixes the bug of determining the level of detail when crossing a lot.

The method of using the last version of the editor is used, and the effect is very general. The levels of the level are unchanged, so the final effect and efficiency are not good.

It's too ugly to solve the boundary cracking problem without using the skirt system. You should be careful with index buffe, and add more indexes to some links at the seams of the two levels of dashboard, in this way, we can solve the problem of cracking. For the second version of the dashboard, I need to learn more about the details of preprocessing and the question of the seams between any dashboard... Quite tangled...