I know I have asked for this before but I keep coming back to it.
You can see from my scenes that I create a LOT of trees. So I'm always looking for ways to economize on trees whenever possible but I simply must have lots of trees out to the visible horizon for many scenes. (A bald mountaintop does not look right even 10 miles away).
The Limit to Visibility and Density Falloff both are great tools for economizing on trees (for Still images). The Density Falloff works great (for still images) but I need economizing for moving camera animations. The Density Falloff tries to create falloff dynamically to the view (I want fixed falloff). The Limit to Visibility works great for moving camera animations. And the Distribution Map defines the patterns of trees within an area.
What I would like to see is this... improved Area definitions or Distribution. Currently, we define which areas will have trees by use of splines. This is great. But I would like to have an additional variable to define where there are trees. Which would be something like splines and a bitmap combined. So the spline defines the shape of the area where there will be trees and a BW bitmap defines the density of trees within that area. So if you had a circular spline and then also had a radial gradient bitmap also - white in center/black at edges - (of course you would need some kind of UVW gizmo to be able to adjust where the mapping happens). These two things would combine to have a circular area of trees that are dense in the middle and less dense towards the outer edges. This would be fixed... not dynamic.
Another possibility would be percentage splines. Where you set percentages on each spline to define how dense the trees are within that spline. 100%=full application of trees per the other settings. 50%=half application and so on. This method would be more tedious as the additional splines would have to be created so is not as ideal as a bitmap (which would be quicker to create).
Once this fixed base of density falloff trees were created for the entire scene, the Limit to Visibility function could be used to view only those trees in camera during an animation. There would not be dynamic creation of new trees in the distance even when the camera moved. The user would be responsible for setting up the density falloff once, to fit their needs.
Just some rambling thoughts.