Can't get Infleunce: Geometry: Normals to work

This SHOULD be simple… Mac OS 10.9.4, Blender 2.71

I have a cube. I want to give it simple, spotty bumps.

  1. Unwrap the cube.
  2. Export UV map.
  3. Open UV Map with Photoshop. Paint black dots on a transparent layer, deactivate the UV map layer, save as PNG with alpha (see below).
  4. Back in Blender, New Material, new image texture for that material, Mapping = UV, Flat projection. See screenshot.
  5. See bumps. NOPE.

What have I not checked?

Lights and color might be hiding the effect. Texture influence settings: uncheck color, blend mode to mix (multiply is not the default), check RGB to intensity, normal value to 1

Thx JA12, but I tried all that before posting - No joy.

Fortunately, I think I hit on the solution. DON’T PAINT WITH BLACK.

It turns out that black and alpha don’t give the best results for bump (without going all out and getting CrazyBump to do some refining for you). The best bet is to think about black = Transparent = NO BUMP, and any level of grey higher than that as MORE BUMP.

Reproducing the same file with a white color on transparent background did the trick. Also, ticking Image Sampling > ‘Calculate’ creates a far better interpolative, smoother bump gradient that’s adjustable, positively or negatively, using Influence > Normal.

If i’m not mistaken terribly - black to white is relative bump range -1 to 1 and 50% gray should be zero bump. No alpha at all is involved.
Only refinement could be add slight blur to eliminate possible lack of antialiasing (use of sharp brush) and jaggines introduced by that.

bumps map !
you need grey map
black and white wont work !

take you black white image and modify it in Gimp to add some blur and it should work

happy bl