So 1 Blender Unit is usually taken for 1 meter. Given that scale, how can we make a bump displacement texture that has 1mm (0.001bu) of height in Cycles?
Let's assume the texture has both pure white and pure black regions, since shades of grey alone don't give us practically measurable information.
I couldn't wrap my head around how to calculate this, especially when taking scale of the scene into consideration. Like, if you are looking at a brick wall from far away and you know the bricks jut out about 1cm (0.01bu) from the mortar, how would you go about preparing a texture with the appropriate bump scale?