Mix Shader texturing?

[RealityFox]

I've been messing around with the mix shader and I'm not having too much luck when it comes to using the Normal Map/Bump Map stuff. How does one use them properly when it comes to the mix node? Should both textures have the normals and bumps? Or is it a waste and should I only texture one of the materials?


This is what I have right now:


And I feel as though the back wall (Brick Node) doesn't really pop enough, I can't seem to get it much better than this and I also cant seem to get my floor to pop as well (Also a mix node) - Floor isn't a big deal but before when I was thinking about doing a different shot it didn't really feel like it was 3D :/

I looked through the manual but the manual is really not very helpful with this...

[FooZe]

Hi RealityFox,

Yes, you will need to bump both materials if don't want one of them to be a plain surface.
Also if you want these to have more striking details, you could add a specualar map too.
The normal map will always over-ride the bump map, so you don't need both.
It could be that you need to tweak your normal and specular maps, or it could be the lighting.

Bump and normal maps tend not to work very well with uniform lighting, lighting from the side will emphasize the effect.

Thanks
Chris.

[RealityFox]

Ah okay, that makes sense now. I thought doing a bump ontop of the normal would help it more but I didn't see a difference. No wonder.

So how should I apply the specular? I was messing with that as well with my floor and I wasn't sure what I was doing there either :/ - Should both materials have this? Or should only one? Do I plug it into the mix node? Mix shaders are a mystery for me still...

Also, for the colour texture node, should I plug it directly into the mix node or should I have both materials use it directly?

I looked around the forum and can't really find anything on making advanced materials/textures, is there any resource for such a thing for octane?

[FooZe]

Hi RealityFox,

For the specular map it really depends on what you are trying to do.
The mix materails are exactly that, it's output at any given spot is a mix of both materials, governed by the amount parameter. ie: amount full one way means one material, full the other way, the other material.

Most likely you don't really need a mix material for the floor or walls. A glossy should do with a specular map, roughness map, diffuse map, bump or normal map and then tweak the index to give the balance between reflection and diffuse that you want (in combination with the specular map's intensity).

The most common use for a mix material is to drive the amount by a texture (rather than a plain value). This means you use the amount texture to 'paint' one or the other material (and everywhere in-between) wherever you want. Quite often a uniform mix of a diffuse and glossy material is not necessary (A plain glossy will do). The exception is if you are using the transmission/emission/absorption/SSS or matte options of the diffuse material.

The Standalone manual is a good resource to find out what all the materials are for.
http://render.otoy.com/manuals/Standalone/?page_id=292

Thanks
Chris.

[RealityFox]

Ah okay, this is making more sense to me now, I'm used to other rendering software that suggest using the mix shader in order to create a nice wall/floor material so I just presumed the same was for Octane. I did go through the manual before, but I find that it lacks in telling what sort of combination of material may be good for certain situations. At least the last time I went through it, which was a while ago, so I may just be forgetting some key parts :/ - But thank you for your help, it really cleared up some misconceptions I had about octane.

- I clicked the link and here is my issue with the summary of the materials: Glossy says it's good for plastic or metals, but to me that doesn't mean it's good for flooring. So I thought mixing the diffuse and glossy was a good choice (as it is in other software). This is mainly where I got my confusion from I suppose.

And what makes a good roughness map? - I actually never really heard anything called that before. Sorry for all of my questions, I'm rather new at 3d rendering still...

[FooZe]

No worries,

If you want to control the roughness based on UV co-ordinates (ie: rough in the cracks in the wall or some such) you can do this with a roughness map. It's just the same a the diffuse and specular maps but it controls the roughness value. An example might be something like a car tyre, rough on the tread (where it is worn) and more glossy on the tyre walls, where the 'spray on shine' isn't worn off yet.

You might find the live DB very helpful to see how others make their materials. Mixing diffuse and glossy isn't a bad idea in general, it all just depends on what you like your material to look like. It could be the case that you want to get a material that looks like bumpy wood underneath a perfectly smooth shiny lacquer, in which case you want to mix a diffuse material with bump map with a non-bumpy glossy material to provide the sheen.

There are no rules

Thanks
Chris.

[RealityFox]

Ah okay, I'll be sure to play around with my roughness maps a bit and see what I can get. I presume white allows for the roughness to be seen and black hides it?

And Thanks for the further explanation on the mix shader, it's a bit easier to figure out when I want to use it and it sounds like it is something I would like to use for the wood flooring. I never really tought of it like this funnily enough.

Regards,
Samuel

[FooZe]

White will be full roughness black will be smooth. Have a play with the roughness slider on a plain glossy material and you will see what it does.

Thanks
Chris.