Probability Maps
Alright ive seen a few people asking how to do this, so I thought I might make a quick tutorial.
All this stuff I learnt from the Twisted Dirt guys.
I use Photoshop. But you should be able to do this stuff with any good paint program.
Ok so this is how I made my Probability map for my track The Only Way. Its a 2 displacement map track.
First I started with my main tile textures-
Then I resized them to 256 x 256. Next I went to canvas size and changed it to 1280 x 1280. So that the main tile is centered.
Next I resized my perimeter tile to 256 x 256 and pasted it next to my main tile so it looked like this-
I then took a black paint brush and painted everywhere that I didn't want trees. Then I got a brush about 80% white and painted
where I wanted lots of trees like the insides of corners and stuff. I then painted the rest about 50% white/black.
Next make sure you ROTATE THE MAP 90 degrees COUNTER CLOCK WISE. I always forget this.
This is what it looks like now-
So then you just have to save it as yourtrack_prob.tga (24 bit) in the same dir as your project, I have a different one for every track
Go into the editor and generate trees and they should be just where you want them =).
Also is your track is a Baja or Enduro you need to remove you map before you bundle or it will increase the size of you track from anywhere between 5 - 100mb. It does this if you are changing the *.ini file to except the user pic. (thanks to garagedog - www.mcm2links.com for this info).
It pretty easy when you work it out. Any other problems just email me here.