Two weeks ago i found some interesting and free software for terrain modelling.
This sofware contain a huge amount of pro features for creating 3d terrains:
http://www.demenzunmedia.com/home/terresculptor/
I played few hours with this software and i have to say it’s really awesome stuff. For me most important feature is simulation of hydraulic and rain erosion which is able to create realistic terrains.
Here is list of features:
http://www.demenzunmedia.com/home/tsfeatures/
And for me as a user here is very important information that Terresculptor is still developed step by step, and hundreds of new features are waiting to get on roadmap or almost ready to be implemented in next build. If anyone want to help a guys from Demenzumedia in developign their product - here is a Patreon page:
Greetings from Poland