node editor problems

[mitchino]

ok so now I want use bump for an area, but I want a raised area defined by a mask, and within that area there is a paper texture.

I'm trying to use a c4d layer shader with an image for the shape and a noise layer for the paper texture, set to multiply.

Can't get that to work either! Any ideas?

[aoktar]

ok so now I want use bump for an area, but I want a raised area defined by a mask, and within that area there is a paper texture.

I'm trying to use a c4d layer shader with an image for the shape and a noise layer for the paper texture, set to multiply.

Can't get that to work either! Any ideas?

Don't use c4d shaders especially layer node without really need. They will be slow and can trigger unexpected problems. Because they are rendered to images on each changes and result will be assigned from these images.
You can use octane's mix/multiply/invert or gradient nodes to combine textures. This will be calculated by renderer by runtime not as c4d shaders.

Post your material with textures if you need more help. We can do a setup as an example to you.

[mitchino]

OK that's a major breakthrough - feeding my noise and an alpha mask into an Octane multiply node and then into the bump gets a good result.

What if I wanted to have a high bump for the alpha or overall shape, but a low bump for the noise or surface of the shape - how would I achieve that?

[aoktar]

OK that's a major breakthrough - feeding my noise and an alpha mask into an Octane multiply node and then into the bump gets a good result.

What if I wanted to have a high bump for the alpha or overall shape, but a low bump for the noise or surface of the shape - how would I achieve that?

You can dig gamma/contrast parameter in noise. Or connect multiply it by float texture. Or use colorcorrection.

[mitchino]

Thanks - more questions:

How generally, is bump map height/strength defined/controlled in Octane?

Can I have a bump and a normal map together on one material?

[aoktar]

Thanks - more questions:

How generally, is bump map height/strength defined/controlled in Octane?

Can I have a bump and a normal map together on one material?

There is not any bump strength. Same effect can be obtained by intensity of maps. Normal+bump is working well since a few recent versions.

Take a look for this starter videos. They have lot of undocumented information.
https://docs.otoy.com/#28Cinema4D_Plugin_Edition

[mitchino]

Thanks - c4d has a really cool normalizer shader that allows you to use bitmap bump textures in the normal channel on the fly.

Can Octane do anything like this or do I need to create my normal maps elsewhere?

[mitchino]

OK now trying a simple stack and can't get it to work!

I have a label with thickness, just a poly mesh. I apply a base material to it, restricted to the front face polygons using a poly selection set. I then apply another material on top with an image controlling it's opacity. This material overrides the base material and then casts shadows onto the rear surface of the label.

Why does it not just stack on top?

Cannot see what is wrong with my setup.

[aoktar]

check this. Octane doesn't support front/back face assignments.

[mitchino]

Right, I've made a new poly object from the front surface of my label. I've assigned an octane material to it that uses my label image in the diffuse channel. I've gone into body paint and adjusted the UV map so the texture fits properly. So that texture is applied to the label using UVW mapping.

I then duplicate that material and set it to a red colour and use the same image map in the opacity channel, selecting a different layer to use as the mask.

I then apply that material to the label, using the exact same UVW mapping, and it doesn't line up.

Why the hell is this so HARD?