Cineversity

Hi all, first post “fresh meat” here!

I’m having an issue with the dirt map and getting it to show appropriately when I adjust the scale of the geometry.
In image 1 you will see that at roughly 200cm I like how the dirt map is showing up but then when I scale the object down to 2cm (20mm) I cannot get the dirt map to look the same no matter how much I play around with the dirtmap sliders?? I’ve tried every combination for the past hour trying to get them to look the same but can’t?

Any guidance/solutions would be very much appreciated.
Thanks!

Hi JBird,

Dirt produced automatically is normally based on the “angle” between surfaces/polygons, given your example. Since the ornament and the scales have a different “geometry in this matter, you might be out of luck to get both at the same time with one shader. Scaling is a different discussion. There are ways to have several materials working on your object. Separated by Polygon Selection, or by alpha channel.

Dirt stays in areas that will have no contact to the “real world”, as in touch by hands, so it looks rather right to have in the smoother parts less. Anyway, if you need to ahve it equaly or in any other strength, I hope I can provide an example that allows you to work as you like to.

Please provide your scene file, with just the object and the shader you use. I’m also not certain which release you use.
I guess you don’t want your model shared in public, so please check you Private Messages (here on Cineversity PM).

All the best

Awesome thanks Doc! I’ll send it right over. Also I’m using R17.048

Yes it was very clear to me I wasn’t going to be able to use the same shader on objects of different scale. This is why I mention that after an hour of messing with the shader it seems impossible to get the same effect with the dirt shader on smaller models as it is larger ones.

“There are ways to have several materials working on your object. Separated by Polygon Selection, or by alpha channel.” This sounds interesting.

Sending file now.

My mistake to think about that the “scales” were more or less OK and the arrows more of an comparison. I get it. Hence why an scene file is always better, images haven’t worked so well, as they leave often some room for interpretation. Thanks for sending the model, I will look into it when it arrives. I hope I have the version/release here that you have used. For me the Dirt Shader was used way back in time, and I never thought of it as ready for prime time, as it was a weird version of an AO (Ambient Occlusion) shader back then. I will see in the file all I need.

Thanks for the file, JBird.

When I read the name “Dirt Shader”, I think of shaders used around a decade+ ago. So, I though, perhaps he starts with a very early version, and I saw, you did not. As mentioned above, this was a rough version of the Ambient Occlusion Shader, way back in time, and not a nice one either, IMHO.

Then I opened the scene file, and to my surprise it was filled with plug-ins I don’t have, nor that they are parts from MAXON: Octane doesn’t run on any of my graphic cards, BTW. The Dirt shader is super old, but I never know if someone created a new one and named it that way. So, it is working, as many old things continue to do so, but do yourself a favor and try not to. ;o) My suspicion was it was wrapped in the shader, which had no plug in in my installation to see it.

The replacement would be, for example, the Ambient Occlusion Shader. I have deleted most of the model, and left only a patch. I have set up a Ambient Occlusion Shader with a rainbow gradient, so you can easily see where the gradient and the dirt would work.. Adjust the parameters to your liking. The AO Shader should go then into the Diffusion Channel. Color [channel] should be used for pure color and Diffusion only for the brightness, to keep things manageable and easy to adjust. I see it too often that things become mixed in the Color Channel, which might lead to problems on the long run.

Some random thoughts, the scale you chose and the density of the object might be needed for your scene. If it is only small in the scene, it is way to dense perhaps. The file was 127MB. But that was not the question.

In BodyPaint 3D, you could paint the areas that you need differently, this “texture” can be then used as mask in an alpha channel. The suggestion with a Polygon selection as separation will work as well, but based on the huge model, I’m not certain if that is a good idea, as the Selection Tag has to store all the points, and that might be quite something to read in and out each time. Given the fact that you have the Octane Render, you like to have a super fast preview, perhaps even realtime. Neither the dirt not the AO shader will support that idea. If you like to be fast, have lower res models and baked textures for parts in the scene that needs a lot of calculations.

The Dirt as well the AO Shader are very tightly connected to the amount of geometry involved. Each one adds a lot of time into the render pipeline.

All the best

Thank you for the speedy response Dr. Sassi!

I think I left out one important detail though. I’m rendering with the octane plugin so my material was an octane material. Does this change anything?

That said, your response is so far over my newbie little head that I’m going to have to read this multiple time in an attempt to digest SOME of it.

*Also how did you create that window on the screen so you could see how the shader was working?

Should I be getting C4D/octane help from otoy?

Hi JBird,

The little window is the “Interactive Render Region” [IRR] option/alt + r, and again to switch it off. The little triangle on the right side is a parameter to adjust speed vs quality.

All I said above was for native Cinema 4D shaders. Perhaps we talk about different things here. If you have an Octane question, then perhaps yes, the Octane based sources are the way to go.
“When I read the name “Dirt Shader”, I think of shaders used around a decade+ ago. So, I though, perhaps he starts with a very early version, and I saw, you did not. As mentioned above, this was a rough version of the Ambient Occlusion Shader, way back in time, and not a nice one either, IMHO.” I guess I made it clear that I talk about native C4D parts here.

Since we have a lot of application providing information to C4D or using C4D as source, and a lot of 3rd party render, I guess I would lose the catch up game with the constantly changing marked of 3rd party render:
http://www.maxon.net/en/products/workflow-integration/render-engines/

Sorry, if you meant the “Dirt Node” in the shader tree of Octane (or Node Editor to be precise) and I meant the “Cinema 4D Shader” from the past.
Since you mentioned that you are new to C4D, “fresh meat” as you said, I excluded the idea of Octane at al, as it makes no sense to me to mix both during the first steps in C4D. I get often scenes filled with 3rd party stuff unrelated to the problem and I often have no idea why this stuff is even in it: It is never mentioned as the problem nor in the later conversations. I get that this was what you had in mind. I have re-read your initial post and there is no mentioning at all about Octane. Things like that happens and part of the game to clear and find a solution.

My suggestion: Learn first C4D and then add 3rd party stuff.  But you might have your reasons to learn first Octane before you know C4D at all.

To check out the manual would be certainly a first step:
https://docs.otoy.com/Cinema4D/?page_id=1934

These parts you mentioned seemed to be native Octane nodes, not in any way specific to C4D, as shown in the image below.
Yes, that is certainly then something for the Octane forum/support.

The simple answer, and I do not even pretend to know Octane: the scaling down of the Object in this extreme way needs certainly and adjustment in similar magnitude.I guess the terms Strength, Details, Radius and Tolerance are easy to adapt, the Invert Normals can be ignored here for this case. I would start, again no idea about, by adjusting the Radius by the amount of the scale, then the Details and the two other values. A tip: scale down to 50% first (make tests) then 10% to make it easier to see what is going on with the change. Then you have enough knowledge to get down to your final scale.

My best wishes

Yeah I bought c4d so that I could use octane inside. I’m new to c4d not 3d in general.

Thanks again for all you help Dr, you have been very informative!

Thanks for the nice feedback, even I moved in a zig zag here, trying to find out…

Yes, that makes sense when you move to a new app and use the familiarity from the render engine then.
Being often like a detective here to find solutions, doing deductive work, I though, if that would be a transition from app A to app B, then he would have tried the scale down in his previous app, to see the difference in working (as Octane has a lot of apps made compatible to their rendering). Well, my conclusion were wrong.

Anyway. I added a little tip to my last post, perhaps you have missed it, as I was done changing when I noticed a new message. Perhaps start with a lower scale amount, to see how much adjustment of the slider is needed. I clicked through the Nodes available, but nothing seemed to support an option to have the values scaled down, proportionally as needed to fit to the scale of the model. Radius would be my first candidate here to explore… Again, I have no clue here. ;o)

Thanks.

My best wises.

Yes radius is the one for this but it still doesn’t look the same as it does on a larger model no matter how much I fiddle with the sliders.

JBird, I tried to find a manual (e.g., the standalone should explain all parts…), in the hope to have a proper link for you with a clear definition of the parameters.

All I can find is clip:
https://youtu.be/5ajlSIKEF04

I guess for this small scale , after adjusting the radius, the details must be much higher.
Again, I’m not very familiar with it, but perhaps place the Object under a Null Object, and scale from the Null. Just a wild guess, and I’m not comfortable with guesses.

You might be more familiar with the Octane>Settings> C4D shader> Size. If you like to render the example in C4D native ;O)

Again, since the Octane render is pretty limited based on hard ware requirements, I can’t run it here. I downloaded just the demo, as the interface of it is available anyway, even the render can’t work with any of my hard ware configurations. When it runs at least on all hi-end graphic cards available, I might look a little bit deeper into it. For now, it seems to be a niche product.

Good luck