Wilbur Precipitation-Based Erosion adding weird bumps

[Rubikia]

Hi there,

I've been using Wilbur quite extensively and had a lot of fun with the programme and it truly is powerful and able to do a lot. I don't know the ins and outs of it, but I know how at least to do what I want with it thanks to Waldronate's help

Recently I have been using it to erode a large heightmap I created with Inkscape with 9 layers, and it worked well for it when I did it at A1 scale. I have increased the size of the heightmap layers in hopes of having a 20,000 x 14,127 pixel sized map, but this is where my Wilbur renders have been running into problems.

I set the offset of the first layer of mountains this time to 100, and the mountains between 100 and 400, then setting the fill value of the rivers to -1, and the height clip low=0.01 and high=10000000. I then generated noise at 100% using the river mask, and then applied 25 passes using the land mask. After that, I selected the rivers again and inverted, setting its fill to -1. Then I applied 10% noise using the river mask, set the height clip again, and ran 25 passes using the land mask, and repeated these settings afterwards but with 5% noise.

This worked well aside from about 1 quarter of the map having weird bumps across it. Unfortunately, I only noticed this at the very end of several day-long process of rendering.



I tried again, completing the erosion cycle but the same bumps are appearing.



And right now, the bumps are starting to appear once more during the operation (this time I set it to 30 passes in the vain hope that would change something).



I suspect that these bumps must be what is left of the percentage noise, but I have no idea why they are not being eroded or why its a very particular area of the map.

I would greatly appreciate any help or advice with this issue.

Cheers,