Why does my grayscale displacement map shrink the mesh?

Flortale

In photoshop I created a grayscale (128,128,128) displacement map.  I used white (255,255,255) to draw some lines.  When I apply this displacement map to a sphere, using the default IRAY surface settings of 1.0 displacement, 0-.10 min, 0.10 max, it shrinks the sphere. 

I thought the whole point of a gray scale displacement map is that white creates a popout effect, while black creates indentations, and gray keeps the mesh at it's default height. So why is the sphere shrinking?

Chohole

Whit is the raised area, mid grey is flat and black is the lower area,

lilweep

Chohole said:

Whit is the raised area, mid grey is flat and black is the lower area,

they said they were using mid gray (128,128,128) allegedly.

codex34_f5f1fb6f55

Assuming your rendering the viewport at the same scale, when you overlay the one on the right over the one on the left, it's the same size, so it seems it's working normally.

Optical illusion because it's raised the white parts?

Also your subD is at 0, go to 1 or 2, it will be smoother.

Flortale

Guys, the UV map was poorly done and it caused problems somehow, I don't quite understand it.  I used a different sphere with a different UV and the problem went away.