Softwares for creating splatmaps and overlay map

I just noticed Tom’s Terrain Tools script collection. I would like to try creating splatmaps and overlay maps for my terrains but I don’t have Terragen. Is there any other softwares/workflows that can be used for creating splatmaps? Tom’s Terrain Tools tutorials don’t talk too much about creating the actual splatmaps and overlay maps (format of image file etc.). For example, can I use Gimp for painting roads and then bring this image into Unity?

I spent a couple hours looking for an answer to this question so I figured I would share my findings.

Today I bought Tom’s Terrain Tools script collection and then discovered the workflow problem. I started with a terrain I made in Unity with the integrated “Terrain Toolkit” made by SixTimesNothing. I was happy with the Terrain I made in Unity, but wanted a nice splatmap to place my trees, grass and rocks and other nice details easily. To my nasty surprise I found that I coudn’t import the .RAW file into Terragen 2 to make the Splatmap. Tom had only described making a terrain in Terragen 2 and also creating a splatmap that could then be imported into Unity (after using Photoshop to convert the file.) That’s a nasty workflow problem.

So… I searched and found Fractscape: starscenesoftware.com - starscenesoftware Resources and Information.

With this wonderful tool, you can use the integrated Unity “Terrain Toolkit” to procedurally generate terrains in .RAW, and then import it into Fractscape to make a nice splatmap. Or you can just make your terrain in Fractscape and also detail it in Fractscape.

The workflow problem is solved! I’ll see if I can use Tom’s Tools to import the splatmap to make trees and grass or not, and I’ll post an update.

I haven’t gotten to the problem of the overlay maps yet, but when I do I’ll post something about it. Oh joyous day!