Hey guys, i used the brush tool to add massive trees and the “Create tree colliders” is checked but still the player can go through them. How can i fix this?
hello, i had similar question!
this helps.
Hello my friend, i also have thought that technique in you post andi will try it and tell you 
Tried and worked, thank you 
The “create tree colliders” option doesn’t work quite like that. Instead, you may want to add a capsule-collider manually by following these steps:
Find the tree you want in the Project panel.
Drag it out as a prefab onto your map. (It doesn’t matter where, just so you can see it)
Select the tree, and in the Components menu, under Physics, add a capsule collider.(Losing the prefab is OK.)
Set the radius of the collider to between 0.8 and 1. Make sure the height is about 20.
Make a new prefab and call it Palm(Collider) and drag your new tree into it.
Under terrain tree painter add the tree called Palm(Collider).
Place a few trees, and you should be ready to go!
Press play, and the trees should now have colliders. If you want more trees and terrain textures, there is a great collection available for download here. Good luck!
Original Answer: I can walk through trees? - Unity Answers