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Hello,

I am currently trying to build some procedural materials from noise textures (stone and ceramic), using the Cinema4D plugin.

Regarding the bump, there is not setup except the texture itself. To my understanding, to convert a gray scale texture into normals, which is what a bump channel should do, you need a reference depth. You have a corresponding setup in Cinema4d which is the intensity. So my question: What is or how is computed the depth value considered by Octane for this conversion ? Is there any way to modify it ?

Thank you for your attention.

Hi,
have you tried with Octane procedural noise nodes?

Alternatively, from v2020.1-RC2, there is a new option for auto converting c4 shaders into OSL Octane nodes.

Currently it works for C4D the Noise and Gradient nodes, but more supported nodes are on the way for future versions.



ciao Beppe

Thank you Begep4d for your answer.

Yes, I have tried the octane noise node and I also use the C4D noises.

One partial solution is to use the normal channel instead of the bump. It is possible with noise to introduce normal distortions providing very interesting effects. Nevertheless, I fell that the bump channel can be of interest, for instance to create small holes in the material.

But I would like to come back to my question, which relates to the definition of the bump channel. Would be interesting to have this definition, as this would help me to better figure out what is feasible or not with this channel, and how to prepare the content for this channel. Probably, the answer is a single value or formula which links the greyscale to depth for the computation of normals.

I have a few additional questions:

- What happen when bump is used together with the normal channel. This looks to work, but not always easy to understand what I see.
- I observe that if I disturb normals on non flat surfaces, the smoothing looks not longer working and facets become visible. Is there limitations there ?

Thank you for your help.