(02-09-2023, 03:23 AM)Relic Wrote: ....I figured I could fix this by applying a gradient around the boundary selection of the image in gIMP to soften the edge between my greyscale image and the black background.
After some google searching I saw there was a tutorial for gradient border select, and the image looks to be similar to the affect I'm trying to achieve, but it was on gimplearn, which seems to no longer exist.
If you can remember the name of the plugin someone might have it archived.
Is it something like this ? Starting with a regular FG to BG gradient and a selection
(1) reverse the colours / color space linear / Shape Shaped (angular)
(2) Draw in the gradient - anywhere - any length, it does not matter with (angular)
Click on the gradient line to make a new stop. Adjust this and the center point sliders either side.
The gradient now shows as a temporary Custom. You can save by right click in the gradients dock and duplicate.
(3) Blending set to curved.
or is it actually the rectangular border shown in your example ? Do you want to add that to the height map ? Basically the same way but with increased canvas size and a selection of the (new) border.