Quote Originally Posted by waldronate View Post
Using a selection to prevent the final write will do something. The basin filling will still happen in the internal temporary surface, but it won't carry through to the final result to unselected areas. This technique will likely result in a big hole unless you're selecting the basins themselves.

A really ugly technique that will carry through into other filters such as incise flow or precipiton erosion is to paint a value of -1 (or negative something large) at the low spot of a valley that you don't want filled. The basin fill algorithm has a "feature" that places below zero always act as sinks and so the fill will drain away into that little spot. You just need to remember to fill the spot before moving on to do other things. A small mask and median filter will avoid it. If you're going to force that valley a lot, making a selection image and loading it for forcing spots up and back is an option.

The long-term goal (about twenty years now) is to allow multiple surfaces, which would allow copying to a source and cloning back into the main area. I don't see that happening any time soon, though.

If I ever get around to adding additional annotations for a surface instead of just straight height fields, allowing logical sinks without breaking the surface (that is, the sinks get applied before the fill and restored just after the fill) might be a useful feature.
I am not sure to have understood what you mean by doing a paint value of -1 applied to a whole world?
I usually do select -5 to 150 m for example, apply noise 3-5% and then fill , then again noise then fill then I use flow erosion , the problem is I do this more than one time because usually it creates straight rivers that I do not like much , I am not sure if I can improve the way I do this because I work on huge maps of 21k and so Its hard to keep under controll all the little holes it creates the selection.
I then proceed to gradually increase heights selections like 125-800, 700-1500, 1400-2500 and so on , but the futher I go ahead I notice that it erodes a lot of the nice shapes of the mountains that I previously created in other softwares like terragen or worldmachine. That said I also rarely use rain erosion because it creates on my world an unnatural zigzag appearence on the coastlines that seems unnatural at least from that huge size perspective, I usually so use a 4 way and a 25 power minimum but only near water areas or otherwise it destroys all the interiors .

Another feature I might sugest to add is ability to pan and use the little hand icon to move around the map view while in the preview mode of a fluvial erosion , because its locked as is now and also doesn't allow to zoom around and if too far away from zoom it doesn't even show up the preview changes... Anyway I have to say that I love your program, and for me is one of the best if not the best for that kind of works!