The idea of having the HammerEditor/WorldCraft editor tools in Unity is great! However, installing this package failed for me due to being too outdated to work with current Unity versions. But maybe other guys have better luck.

Really useful tool and great for level design. Using LWRP requires the materials to be remade, and there can be some lag when using small grid sizes, but otherwise has been incredibly good for me.

I've been using this asset for a long time now, and I still believe it to be one of the best level creation assets out there. I hope this never disappears!

It's free, and this is very good: if you don't have the money to buy 3D modeling software like Maya or have no skillz to learn Blender, this will solve most of your problems if you want to start to build a game. Quite complete and very user friendly to be a free asset. However, the software easily go into problems when you try to subtract with solids in "strange" angles or with a bit more complex meshes... you will find broken meshes, missing faces, etc. It is a good tool for inexperienced people and for small productions, can't hold up for AAA games... but can still help you (for free) patch up parts of your levels where you just need quick fixes and such. 4 stars, just because the subtraction system REALLY needs to be improved.

Unbeliveable, that a tool like this is given away for FREE. This tool has easen so much my level design. Also, seems to be very stable and bugfree nowadays.

I don't know if all these 5 star reviews are from an old version, but what I found was a broken, buggy mess that rendered this software useless. *Dragging the edges of a brush using the provided handles often did not work right, leaving me with a brush that suddenly translated and rescaled to incorrect values after I finished dragging an edge. *Finicky inspector viewing. Many brushes would just stop showing up in the inspector (the inspector would flicker for a frame and then show blank). Reloading the scene would often fix this momentarily, but as soon as I did some editing, the problem would come right back. *Undo can get into a bad state

Does not build in prefabs.

The question in title. Please help.

I designed and built a prototype for a complex level in just a couple of hours using this. Everything seems to work just as you'd expect and it's sooo much faster to build with 3d than messing with 2d planes.

So sad this extension went open-source. Nevertheless, is still being supported. I discovered CSG today and I like it a lot more than ProBuilder. It's very easy to learn and it is 100% intuitive. You only need to watch a tutorial of 10 minutes and you are ready to go.