We have documentation for new TG3 features underway. As new documentation becomes available we'll link to it in this thread. Some of it may still be a work in progress but at least it will get you started in the right direction with all the new things TG3 has to offer.
Here's the list of documentation:NEW Working with Objects
This new guide contains information on creating and importing objects, controlling object display in the 3D Preview and manipulating objects and shaders in the 3D Preview. It also links to some relevant existing documentation.NEW Command Line Reference
This is a mirror of the command line docs included with the TG3 download, but it does include links to the Windows, Mac and Linux versions of the docs.Render Layers and Render Elements (TG3 Professional)
Explains the Render Layers system in Terragen 3 Professional, including Render Elements.The Library
This is a guide to using the Library and Library window in TG3.Population Instance Editing
This guide describes how you can edit individual instances in a population using new capabilities in Terragen 3.Population Instance Caching
This page tells you how to make use of population instance caching to speed up population loading.Populator v4
This is the documentation for the new Populator v4 node, which has powerful new features such as instance editing, instance caching and multithreaded population to speed up populating on multicore machines.Image Preview Window
This page describes the new Image Preview window.Geog Heightfield Load node
The Geog Heightfield Load node can load and georeference many DEM formats.Terragen 2 Preferences
The Preferences documentation has been updated for TG3.Terragen 3 Menus
The Menu documentation has been updated for TG3.Terragen 3 Input Settings
The Input Settings documentation has been updated for TG3.
Don't forget that the main page for TG documentation is here:Main Page