1. How to clone vegetation
This applies to J.A.C.K, VHE and (maybe) Sledge.
It is a really quick technique to manually copy-paste grass, bushes etc.
So, here we have our map:
We need to put some grass!
1.1. Step 1.Make a grass object: (I have a func_illusionary)
1.2. Step 2.Select it, and press Ctrl+C (copy it)
1.3. Step 3.Go into the 3D view, and press Z
OK, now you can move your mouse around :D
This is the "free look" mode.
1.4. Step 4.While in free-look, go close to the ground
1.5. Step 5.Still in free-look, press Ctrl+V (paste it)
After you're done, select all your cloned objects, and press Ctrl+B to align them to the grid.
Hopefully, you'll get this:
In my example, I used a low-res grass texture, so it looks quite ugly :/
Now, if you have a complex object, you can copy-paste it like this.
Basically, this is how it's supposed to work:
When you paste, the entity is placed where your camera is looking at. However, in free-look mode, your camera itself is the entity's center. That's why I said to press Ctrl+B, because the objects are pasted with sub-grid co-ordinates. So yeah, I hope you understand it a bit better.
I accidentally discovered this while making de_kobbl, so I decided to share it. It was discovered in J.A.C.K. so I don't know about the other editors out there.
Now, you can easily copy-paste grass, bushes, trees etc. all around the map :)
This method is recommended if you have triangular terrain. If you have flat terrain, Shift+drag will work just fine, even better. If you don't want to use this free-look method, then it's OK, I understand you.
Happy mapping! =)