When your preview camera angle is not the same as your render camera, 2 things happen. First, the button on the far-left of the bottom 3D preview toolbar "pops out" (becomes shaded as if 3D); it will pop in again if you click it to copy or "set" the view to your render camera. Second, the icon for the next button to the right, which shows the current camera view, will change to indicate it is viewing a different camera. Usually this will be the Perspective camera, which looks like a little pyramid with a red and a green side, but there are other views as well, e.g. top, bottom, etc, each with their own icon. When you click the "Copy this view to the current render camera" button, the icon for the camera will change to be the same as that button, i.e. a small landscape icon.
Object grouping is planned for the future.
There is per-population coloring in the 3D preview in Terragen 3.
Copy/paste objects should preserve any changes that are made to the node settings; it's really just copying the nodes themselves.
The view style of objects is specified from within the node's settings. There will be some new options in Terragen 3.
Some of your other ideas are being considered for the future.
I hope that helps. Look for more information on Terragen 3 soon.
- Oshyan
