I am a beginner in digital image processing and computer graphics. I would like to program a similar behavior than the Shadermap 3 normal editor (displacement layer more specifically).
As shown in this Shadermap 3 demonstration video, the displacement brush allows the user to paint a displacement map (grayscale)
The brush strokes produce shapes with a smooth value transitioning from the middle of the shape to its edge, in this case giving the shape a slightly curved profile. As it is also shown, the shape's profile can be fine-tuned with the brush curve editor.
What combination of filters and/or algorithms could Shadermap 3 possibly use to convert a pixel blob or shape to displacement map with a given width and curve?