How to use Incise Flow for rivers in Wilbur correctly?

[xeyla]

Hello everyone!

I'm having some trouble with Wilbur making rivers. I'm using the Incise Flow to make my rivers, but when I follow the Arsheesh - Eriond directions, I'm getting the opposite effect?
Here is my problem:
This is the direction given: "here are the settings that I recommend: Amount 2; Flow Exponent 6.5; Effect Blend 2."
Here is the minimum I used just to preview what the flow would look like:


Notice the river on the right side of the "preview" button? When I up the flow exponent to 2, that river gets shorter/shallower:


At setting 4, the rivers are no longer there?


And at the recommended 6.5, my map turns into a bump map:


The tutorial has the example map like this, which is nothing like mine if I do the 6.5:


Now, I can see that I should use the lower settings, but my question is why are the recommended setting making my map a bump map? Should the rivers be more deep, or more prolific with higher settings?

That is all for now. Thank you for any help with this mystery.

[woodb3kmaster]

Based on my own experiences with Wilbur, what you're seeing is totally normal (well, not the bump map part, but I can't speak to that). Higher flow exponents actually reduce the size of river networks, while lower exponents make them more widespread. Judging from your results, I'd recommend going with an exponent less than 1 if you want more frequent rivers; I rarely use values above 0.5. However, as Wilbur is waldronate's program, I'll defer to whatever explanation he has to offer on the subject.

[xeyla]

I see. I thought the higher the number, the deeper the river. Thank you for that info. I'll try using less than 1 and see what happens.
I'll give you some rep

[kacey]

I'm having the exact same problem with the map turning all grey, and it's really frustrating so I'll be eager to see if anyone else chimes in on this. I'm also finding that the rivers look really pixilated no matter what resolution I use and am wondering if there might be a reason for this.

[waldronate]

For river flow, the flow field is composed of counts that indicate how many cells are upstream of that particular cell. The general distribution is a small number of large values and many smaller values. An exponent value greater than 1 will make this distribution skew even more towards the higher values, reducing the visibility of the smaller values. An exponent value between 0 and 1 will increase the number of smaller rivers. The default value of 0.6 (2/3) gives something roughly like a typical distribution. Using a value like 0.4 will give you a more detailed network, and a value of 0.2 will give you a whole lot of rivers.

[xeyla]

Thank you so much for that detailed explanation. I was reading a reply from you that was from about 3 years ago, and I was confused by it. I'm so glad you re-stated your reply in a manner I could understand it. Thank you so much.

[waldronate]

I'm glad that I was able to help. I do a pretty good oracle in that I can answer questions, but I'm not nearly as good at trying to guess what questions people might have. Asking questions is a good way to help both you and someone else who might read this later.

When playing with the incise flow tool, another toy to consider is the river flow computation dialog (Texture>>Other Maps>>River Flow). The algorithm in the river computation algorithm is basically the same as incise flow except for a final thresholding step. The numbers for the exponents aren't identical (they're off by a factor of about 50 or so due to the thresholding in the river computation algorithm), but you can get a feel for how adjusting the exponent affects the results just by twitching a slider.

[xeyla]

Ok, I have another question about the program freezing:
When I go to use any filter, like Incise Flow, Fill Basin, or the like, the program like to freeze for about 45 seconds in a "Not Responding" state. After the "not responding" waiting period, it works normal. But it freezes every time I go to use that function. Is there anything I can do to reduce that freezing period? I have upped the programs priority to normal in Task Manager, where it was below normal before, but it still freezes on me. I am using the 64x version, if that helps any.

My computer Specs:

[waldronate]

The flow field finding algorithm isn't the most efficient algorithm and the system is performing a whole lot of work while running it. If you look at the performance tab on your task manager (Ctrl+Shift+Esc, performance tab), you'll probably find that most of your CPU cores are close to maxed out. The flow finding code has pretty poor memory access behavior, which generally means that memory speed may be the big determiner of performance. I didn't bother to implement features that would allow the program to keep responding to OS queries while the operation is running because it would have required thread synchronization and other uglies that slows things down a bit. Because Wilbur isn't responding to the queries, the OS believes that Wilbur has crashed during those times, which is why it shows the "not responding" message.

The only way to reduce the time that it takes it to give it less work, meaning smaller surfaces. https://www.cartographersguild.com/a...chmentid=80066 describes how to get a final surface by starting from a few masks and gradually increasing the size of the image. It usually takes much less time to do things this way than to just try working with the final-sized image.

[xeyla]

Ok, I will read that PDF and use the suggestions in it. I wasn't sure if the size of my map (4k by 4k pixels) was the cause of the problem. I see now that it is. If I need too, I'll just section-up my map into quarters or more parts. I understand your reason to not add in extra features, since building the program itself takes a lot.
Thank you again for your insight. Have a wonderful day!