So 2 days ago I decided I needed some rusted metal in my scene, today I realised I was totaly lost with no clue of what I had done this yesterday or that the day befor so I restarted from scratch or almost keeping two noise texture that were promising and a bunch of node that I used for coordinate and decided to make it more clear so if I was to end up with somthing decent I can anderstand how it work in a month or two.
I get some interesting result but I have some trouble with the rust looking flat even with displacment all over it. The rust looks good on Susane in the preview but with some world light and emiters its totaly flat aint at the jonction where the non rusted metal is suposed to be.
If I remove the world light and emiter and replace it with a single sun lamp, the rust look prety much like in the preview but its not the kind of lightning that I will use in a scene frequently.
A screenshot showing the node setup and the viewport and rendered result.
The displacement by itself can prove usefull for damaged marble statue material I think, so if the rust isent fixable I guess I wont have lost this time for nothing, but I’m open to any sugestion regarding the rust flatness issuean/or anything else that can improve this material.
Thats the changed node setup just aded a bump node after the overlay from the displacement frame, pluged it in all the normals and renamed the displacement frame bump as its not a displacement.
I think part of the problem is the rather dim lighting:
As your rust areas are diffuse only, you will need a bit more of a dramatic lighting to make the surface structure visible. That’s why the very same bump looks so much more prominent on a glossy shader - the light catches in reflective surfaces much better and becomes much more clearly visible.
In addition to that your “Texture Blurer” node group seems to suppress much of the larger scale noise?
This is your setup with just a different lighting (left) and without the texture blurer (right):
In general your procedural textures are quite small - this results in a rather fine “micro bump” structure.
Concerning ideas for improvement:
I’m not sure if you’d see those clear cut transitions from rust to sheer metal in real life. I for myself would expect some zone of starting decay or areas where the rust already started to bloom under surface, but has not yet broken through. Perhaps a bit like this?
That’s a good idea for car and other painted metals. If I andderstand what your speaking about, this efect is due to metal rusting under paint and it’s actualy the paint that bubble. If you look unpainted metal rusting the rust wont start under the surface. It start at the surface of the metal but with paint it do the efect you describe. For this using 2 diferent bump with oposit orientation may be needed as the rust remove metal when the paint is pushed in the other direction,and the efect on the border of my version of the rust may be needed to mark the part where the paint has faled of the metal, I never used bump in oposed direction in the same material an I m wondering if it’s possible.
I wasent realy after rust on painted metal but that can prove an usefull idea I will try to push it but I dont think it will be for this scene as its medieval fantastic and car paint wont make a lot of sens.
I actualy tryed to remove the blur after posting my last message but I was to tired to figure if it was actualy better or not and decided to go sleep and retry today lol.
I think the cracks it’s generate in the texture with the large scaled voronoi are interesting, the tiny ones arent that good and I will try somthing else that voronoy instead.
I tryed to add some anisotropic node to the rust too, with a very soft effect on the mix so it dont turn miror but I dont think the result was that good I have to try to tweek it or change for a simplier glossy peraps but realy soft as rust as almost no glossy.
wanted to add some more metalic thing aroud the rust but I had no real idea how to do old iron so I ended up changing the orange rust into brass and the green one to match the color of copper / brass rust.
