In attempting to create new composite materials, I find it confusing the order in which blender cycles renders materials.
I’ve tried creating several materials for an object but changing the order of the materials doesn’t seem to make a difference. I always end you trying to cram everything into one materai, it quickly become a mess of speghetti noodles which is also confusing as the order in which blender renders them. I think it would be easier to create composite materials if I could overlay them in layers like Photoshop or GIMP.
In other words, I might want to create a base material that has the color, noise, pointiness, etc. A second material on top (or under depending on the order rendered) for scratches, and a third material of dust and dirt that would overlay the base and the scratches with grime.
However, the oder doesn’t seem to make any difference.
Well that’s not entirely true. Changing the order sometimes causes decals and scraches to disappear, so there doesn’t appear to be an alpha transparency between materials. It seems it would be easier to organize and update individual materials than to try to remember what two dozen nodes in one material is creating.
Anyway, if someone has a reasonable explanation of how best to use multiple materials on an object I would appreciate it. There is lots of information on the nodes that make up materials, but very little on how to best use the material stack itself.
The material slots aren’t a stack that does anything - it’s just slots you can assign parts of the mesh to. They don’t interact. Node trees are self contained, to share parts you use node groups.
(I don’t think the following info is answering the question, but it might help: )
Think of mixing as influencing the probability of which side of the tree will be evaluated, not an ordered alpha blend.
The order in the material list is just an index. It applies first material to a selection of faces, second to another selection, third to another one, etc…
If you never click on the "Assign " button in edit mode; first material is applied to all faces of mesh.
For rendering transparent materials, what counts is the order of bounces that will be executed by a light ray.
You can always combine already made materials into a new one. You can copy/paste their nodetree or just group their nodes into a nodegroup.
After creation, a nodegroup can be added to any material of same blend.
He’s wondering if theres any difference when changing the order of material slots. Modifiers do. You have to make sure they’re in right order for desired results.
I was wondering if the order of materials in the stack made any difference. Someone already explaind that it doesn’t.
Your second image is the nodes that make up a materials and it’s definetly important (and confusing) the order in which they are rendered.
I’m very familiar with Photoshop and so I’m looking for an analogy for layering nodes or materials. It appears that one becomes an expert with configuring nodes by trial and error, which is difficult for someone like me who doesn’t have time to model on a regular basis.
I fully understand that if you model routinely, Cycles will one day make sense. But not for me. I’m lucky to get a few hours a month to work with Blender and the Cycles nodes although very powerful are also very confusing.
Thanks, that helps me to understand that the material slots are only useful if you segment the faces of the object using part of the UVs of the object for each material. That make sense.
But then there doesn’t appear to be anyway to use a material to overlay on all the other materials. As in the example I provided, I have segmented an object into a base color and separate UVs for two decals. But then there doesn’t appear to be anyway to then overly dust and grom over the first three materials. To do that, I’ve forced to put everything into one material and figure out where the dust and grime nodes go to overlay everything else. Sounds easy, but I obviously have found the key to success yet.
I can get the dust and grime to overlay, but then the other colors, scratches, etc. all lighten up or turn darker. It’s not like OK I’ve found a way to overlay dust and grime and everything else stays the same. It’s more like I’ve found a way, but all the colors change to either lighter or darker.
I’m sure there is an answer to my problem, I just haven’t found it yet.
Thanks. I’ve been able to figure out that if I create separate UVs from different parts of the object’s mesh that I can add multiple declas. But then there doesn’t seem to be away to add dust and grime to everything without Cycles changing the color, hue, or saturation of everything.
I have an object that has a base color and two decals all on separate UV’s. There doesn’t seem to be a way to add and overall UV that covers the other three node groups with dust and grime without changing the color, hue, or satuation. Everytime I try, everything lightens up.
I’m certain I’m doing something wrong, but I feel like putting a gun to my head after a while. I’ve tried masks, gradients, every color RBG Mix option available to no avail.
I do understand about light bounces with regard to transparent objects.
