Old brick wall with missing plaster. & Bumpmap via nodes possible?

I recently searched a way how to easily display a plastered brick-wall where some patches of plaster have fallen off or have been removed. In my case i needed 3 materials, the plaster on the outside (the one you normally see on a new wall), the rough plaster where the outermost one is gone but no bricks are visible and the bricks themself.

Since I saw the video tutorials on combining materials via nodes on blendernation recently and similar hints elsewhere I’ve found it to be a very quick solution once you know how nodes work (at least the basic stuff).

The “spec” is set a bit too high on the plaster and the grey stuff is a bit too … hm grey, but i hope you see where it’s going.

The texture for the bricks that is used was downloaded from http://www.cgtextures.com/ (bricks->small->‘bricksmall0228’) and the plaster materials are (rather crappy, since i’m not too good with that) modifications of some ‘matlib’ materials.
The bricks-texture is set to be tiling, but it is not seemless … would be a moot point since one can’t see the whole thing anyway :wink: No bump-map for the bricks.
http://www.flickr.com/photos/[email protected]/249879271/

I’ve used one sun light and one hemi for this scene, no AO.

Now what i would like to know is if there is a way to directly use a single texture/mask (not a whole material) as a bump- or normalmap for the final Output here. Basically i just want the plaster to stand out a bit in relation to the bricks, so using one of the modified masks will/should works as a bumpmap. Any ideas are welcome.

Any suggestions to improve the overall look are welcome as well of course :slight_smile:


well, you could add a normal map for the plaster (a geometry node with normal output) and clipping map texture where the bricks show through so it doesn’t map the normal to the bricks. not too sure this would work though - despite the moniker my node skillz are not “mad” yet. my best bet would be a separate material node.

if you can talk to dannybear I would - his latest render has some pretty sick wall materials in it, and IIRC at least one specifically like this

Erm, I should offer a clarification here: A geometry node with normal output is NOT a normal map in the sense of a bump map.

The geometry node outputs texture co-ordinates, which determine the way that a 2D texture is mapped to the 3D surface. The ‘normal’ output gives co-ordinates that take the difference of the surface normal direction to the camera direction, which pretty much means that surfaces facing away from the camera will use a particular part of the texture and surfaces facing towards the camera will use a different part of the texture. It’s got nothing to do with bump mapping.

Thanks broken, now I know that I did read the material-nodes docu correctly … meaning that there (currently) is no way to do the bump-mapping with nodes :(, just in the material themself, no?

One thing that could nicely work around that ‘problem’ would be a way to use a texture-output (e.g like the one on the top in my node-tree) as a texture inside a material (e.g the plaster material) … but i don’t know if this could even work code-wise


Yeah, you would need a matnode some place in there that takes the normal ouput of you texture as input.

Also I think I would go about this a bit differently. I would make one material for each kind of stuff (material!) I was trying to layer, then only use the nodes for the actual combining. So you wouldn’t have to worry about adding in normals in the nodes - Plaster would just be plastery and brick bricky, then use some mixer nodes to layer them.

Okay, I shouldn’t have, but here is an examplehttp://kitsu.petesdomain.com/images/Blender/layer-02-nodes.jpg

It’s a little rough. I would like to have the difference in elevation between the plaster and brick more pronounced…

Many thanks for the example blend file, looks really cool :cool:
But i think it’ll not help much in my case since I basically just wanted to use the output of a RGB-Curve or Colorband nodes (they are there for a reason) as a normal-input and this is not doable as i just learned … that is, if I understood all the docu in the wiki and the comments here right. [1]

Not to mention that the way those vector in/outputs work is way over my head :frowning: … especially since the vector-controls are somewhat hard to use/understand IMHO.

Using a seperate bumpmap for each of the materials is quite logical, but you still need to define somewhere how they will look in relation to each other e.g. worst case scenario: what if i use replacement mapping and the plaster+middle material is 1 unit think? (Just an example, i don’t even know yet if disp-mapping can be used here.)

What i want to say is: You need to define where the ‘step’ is between the different material-bumpmaps. And doing this ‘inside’ the materials just sounds a but un-flexible. Why should I define the step/recess in one of the single materials? Especially if i want to use the raw material someplace else as well? … EDIT: Not to forget that the texture needed for the bumpmap(s) is created via RGB-curve node(s) as mentioned above and I can’t really use them inside the materials. :-/

But as i said … this is going way over my head, so i might be on the wrong track here :-/

Thanks for your help,

[1] One minor related thing: your method shown in the blend file also ‘dents’ the bricks into the wall which i tried to avoid.