Subtle 3D River Banks in GIMP/Photoshop
I’d just like to share a quick and easy way of adding a subtle 3D river bank effect to a perspective regional map using GIMP or Photoshop. It’s not rocket science, but I used it in a recent map and got very excited!
1. Start with your base map. Needs to have pretty strong colours. Your rivers should be on a layer of their own.
2. Duplicate your Rivers layer. Alpha to selection. Fill with white. Use Move Tool and shunt this layer about 10 pixels to the right (or away from the sun).
3. Duplicate your Rivers layer again. Alpha to selection. Fill with black. Move this layer about 10 pixels to the left (or towards the sun).
4. On the white layer, Gaussian Blur 25px.
5. On the black layer, Gaussian Blur 25px. Merge black and white layers.
6. Play with opacity and layer blends to get the result you want. In mine, I duplicated the layer and set the first to Overlay at 100% opacity, the second to Normal at 20%.
Hope that was useful!
Re: Subtle 3D River Banks in GIMP/Photoshop
By no means am I trying to devalue your work but this is a basic principle in illustrating. It's easy to understand but hard to master. All things seem more real with quality line work and excellent hightlights or lightsource and shading or shadows. Indeed it is something I'm still learning.