I need help for make mountains topography

[johnvanvliet]

i reduced the size to 512x512 to make things faster
start with masks of the area


then run a distance transform on the masks
-- gimp with the gmic plugin ( runs on windows )



then i add a plasma noise to the distance maps
using a "grain merge" layer blend


blend the two together with a "lighten only" layer blend -- left
and use the air brush tool to paint light and dark areas .
This is a large island so ...


take the Base image ( above right) and run it through wilbur to add rivers and erode the land



then use the gimp "posterize " tool ( below i use 12 tones) - left
then run a edge-detect in it and you have contour lines ( min. / max. div by 12 )





you can also use the gimp "bump map" tool to use the height map and make a shaded relief




as you can see the height is a bit exaggerated
a bit more normal would be

[waldronate]

Or... You can do all that directly in Wilbur: