layering textures (cycles)

Ok guys, sorry to bug you with this again but I’m really having trouble understanding how to do this in the node setup, there was a really good tutorial on youtube but it was never finished and now it’s not going to be.

I wish to use the texture painter to make a realistic looking object. Let’s just say a simple cube for now, with scratches, rust, chipped paint and so on.

This is how I imagine how it goes (Or how I’d like it to)

1.paint metal under base.
2.Paint paint layer.
3.Use alpha to ‘chip’ away the paint to reveal the metal under base. (How would one use alpha?)
4.Same step as 3 for scratches.
5.Paint rust with texture mask or something.
6.Somehow add bump.

Would I also need AO?

Assuming I’d have to do this in BI how would I even go about this? Then Transferring it to Cycles the node system would have to change again no?

Basically I looked at Mari and thought wow, I’m sure I can do something like this in Blender.

Anyway, have a nice day and let me know if you have any insights.

Cheers.

Hi Tyko,

I do not use blender internal, but I know you can do this with Cycles nodes.

To do layers all you need to do is to create the B&W masks that correspond to layers and do the necessary math on maps to get the various combinations you need from within the nodes (e.g. RGB multily two B&W maps will give you the white areas that are on both etc). An example like yours:

  1. Create a mask for the painted area, create a mask for the chipped areas, create a mask for the scratches
  2. Use a diffuse and transparent node mixed via a factor using all the maps multiplied by the other maps so that you get paint where there are no scratches, no chips, no grime, no rust or whatever else you may add.
  3. Do the same for whatever you want above the paint, but below all the other layers. Mix this result with the result from above (or you might be able to add it…I would need to test to remember how that looks).
  4. Repeat

The actual math for the masks will depend on how you set them up. You might need to invert some masks prior to combining, or invert them for the diffuse component.

As for bump, that is a bit more complicated. If you imagine what a bump map would like like that combine you other bump maps then you will start to have an idea of how to create it with nodes. An example of two bump maps to combine, one is a just a single big bump, and another is lots of small bumps spread evenly. I would expect that the big bump would retain its colour in the map where there are no small bumps, but where there are small bumps there would have to be some adjustment to represent those. Sketch a profile of a height map that would be a cross-section through the bumps that you want, then try to find a way to combine a number of those mathematically to get the result you want. It might be as simple as adding them, but if bump functionality does not register value above 1 then you will need to do some division to get them to fit. I’m not sure, that’s something to test…just “typing out loud” here. :wink:

Thanks for the reply Matt,

I’m not going to pretend to understand everything you said but I’ma give it a go and have a mess about. I have a love/hate relationship with nodes :stuck_out_tongue:

thanks for the reply, appreciate it.

I wanted to answer with pics, but I wasn’t at the right computer. I’ll try to make an example if I get time this weekend (no guarantee! ;)).

I know Andrew Price’s Post Apocalyptic environment tutorial has an example that would help (at least it would make my waffling about nodes clearer!). In that he uses a mask to put some graffiti over a wall texture…it’s that kind of idea I was talking about above, but with more detail for all the ifferent layers you wanted to apply.

I will draw an example for the bump thing and create a file if I get time too (that is one thing I wanted to experiment with anyway).

Blender Matt, if you put the visual explanation you mention, it will be a very precious help for some others too here, for sure… :slight_smile:

That set of 13 or so tutorials on youtube and on blendertutorial.net I think you’re referring to was one of the most well thought, prepared, and presented set of tutorials I’ve come across. Did not get the attention they deserved, I think.

Yep that’s the set of tutorials I was referring to. It’s a damn shame the series wont be finished, but he’s made the existing videos private so I can’t ever go back through them :frowning: