Is this possible: Normal map greeble decaling using Empty

(Shoot, I meant to post this under Materials and Textures category)
I know how to add an image decal onto a mesh using an Empty. I’m trying to figure out if this same method can be used to add a normal map greeble onto a mesh.

I followed the same steps and checked Image Sampling->Normal Map, set map space to Tangent, and under Influence, unchecked Diffuse->Color and checked Geometry->Normal. However, I don’t get what I want. As you can see from the first image, my greeble is shown but the rest of the plane is just black instead of, what I’m expecting, the material’s diffuse color.

My ultimate goal is to programmatically place normal map greebles around a mesh (using python). If someone knows a better way to do this, please let me know. It would be awesome if these greebles could be baked into a normal map but I couldn’t think of a programmatic way of doing that.

Any suggestions or ideas into my problem?

My usual approach would be using dupliverts however placing normalmap ‘decals’ by empties also does work. Only thing is that it seems it needs ‘flat’ level adjustment on normalmap itself by changing blue color so that it does not show as a surface level change when applied.

Happy Blending!

can you explains ome more here

i can see empty moving the map

but what is this
" blue color so that it does not show as a surface level change when applied "

also did you add the bolt head map here
is this with texture painting with a brush ?

and is it possible to add some texture to the ehad her elike zinc plated and how ?


hwo do you change this blue color
in GIMP may be?
or is it possible in blender alone ?

ok but can you add some texture to this bolt head ?
like may be add a BW mask then add a zinc texture ?


Yes, blue square background excluding bolt could be selected and blue value changed in gimp or photoshop; set one as an external editor in user preferences, then it could be called from blender.
What is true - you probably wont be able to put more than some 8 empties overall - limited by available UV coordinate amount for object. It is enough to have one projector and map several textures to the same uvs - all are moved by that projector.
And quite frankly - i don’t know how to combine this with some base texture.

I would say - idea 'bout thousands - busted…

do you any simple example for this in cycles?

i can see how to do it in normal blender with mask and zinc texture channel

but in cycles not certain how you could add a mask plus let say zinc texture
usually in cycles mask goes to the FAC of mix shader input and must be black and white no alpha if i remember well!
mind you here you might have to go to external program to convert normal map to bump map


Take two textures and use Color Mix in Overlay or Screen or any other mode you like - output goes to Diffuse. Any color alpha masking or blending before Diffuse shader also works. Like in gimp, photoshop. Do all what can be done mixing Color; then feed that into Diffuse, Glossy and so on.
Yes, it’s easy in external editor; could be done entirely internally tho using Convert B/W, Separate RGB, Color Mix, Contrast. Just make using node operations what you would do in external editor. There are tutorials out, how to go about convert nm to bump. All what’s needed is included in nodes. Is it really necessary to do it in blender - idk.

i did a quick test here with a normal then converted to BW and
looks not too bad like a bump map !

don’t remember any nodes set up for cycles!
and did not find any on googling

if youv seen any nodes set up for cycles
let me know
would like to make a test and see if it gives good result

but hope we get normal node set up for cycle soon