"Dirt" Question

[tukor]

hey there!
Im using a Mix material with dirt controlling both mats.

Its working ok but... when the object touchs other different object, it creates dirt where they are touching...
In fact, it begins to create dirt when they are about touching...
Its for an animation so im having troubles to fix this... i dont know why it happens.

The MIX material wich contains both mats, i put a colorcorrection with a white texture in multiply. This one contains 2 turbulences, each one of them has a dirt node.

So the dirt is not as linear as with a single dirt node.

Any ideas to fix this please?
Its so extrange.. the material knows when an external object is collinding with its object?

Thank you in advance.

[tukor]

I made an example with two simple objects so you can see it (Dirt.RAR attached)
Instrucctions are in an annotation Tag.

[calus]

Its so extrange.. the material knows when an external object is collinding with its object?
Thank you in advance.

Yes, dirt is similar to ambient occlusion, that's the correct behavior.

To use it the way you want avoiding oclusion with other objects, you need to bake your dirt map to an image texture.

[tukor]

Ok Sir thank you; i understand.

But Im a little noob, could you tell me how i bake only the dirt map please?
Or point me to a link where i can learn?

Thank you again!

[calus]

Well actually I'm also a noob at the new octane baking in C4d , never tried it.

But Aoktar put an example scene and 2 picture to explain the process on the first page of the last v3 beta release:
viewtopic.php?f=85&t=53989

So I'm only guessing here :
First, your objects should have non-overlapping UV.
To bake only the dirt texture, you have to apply to your objects a diffuse material with the dirt in the diffuse color.
You have to use a baking camera (parameter of the camera Tag) and put an ID tag for each objects and render a "diffuse_filter" pass.

Good luck !

[tukor]

Ok thank you very much!!!!