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Stacking Materials

Posted: Wed Nov 05, 2014 8:17 am
by skoeth
Hi guys,

im just wondering if it's possible to stack multiple materials on one object in Cinema.
Like with the native material system it was possible to e.g. put a material with an alpha over a plain material
so you can see something "alphaed out" over the plain texture.

Using Octane it will only show one material and ignore the other.
Using MixMaterial fades them together but thats not what i want.

I have like a fresnelled plain texture and wand to put another "glassy coat" material over it.
Any ideas how to achieve this?


thanks you,
j_p

Re: Stacking Materials

Posted: Wed Nov 05, 2014 9:19 am
by pBarrelas
You have the Mix Material for that.
Inside the Mix Material, you have Material 1, Material 2 and an Amount parameter.
Material 1 is your base material and Material 2 is your coat, in the effect you're trying to achieve. Having a Float Texture in the amount, works as a slider to control how much you want from either materials.

Re: Stacking Materials

Posted: Wed Nov 05, 2014 9:40 am
by skoeth
thanks for your reply.

If i'm understanding you right that means you can only like blend the visibility of the materials.
What i want is both materials have 100% visibility but the "coat" has an alpha e.g. a typo.

Re: Stacking Materials

Posted: Wed Nov 05, 2014 10:17 am
by NVN
i ask the same question long time ago.
Mix Materials are bullshit......

for ur problem.
use a octane fresnel shader for blending.

Re: Stacking Materials

Posted: Wed Nov 05, 2014 10:24 am
by atome451
That's what explained pBarrelas.
With a black and white texture (like an alpha or a grayscale bitmap) in the amount of your mixTexture or mixMaterial, you'll be able to do what you want.
With a mixMaterial, the white of the amount will show the material 1 and the black of the amount will show the material 2.
It's reversed for the mixTexture (i don't know why...): the black will show the texture 1 and the white the texture 2.

OF course, all intermediate greyscales between black and white will show an amount of the first and the second material/texture.

Re: Stacking Materials

Posted: Wed Nov 05, 2014 11:01 am
by skoeth
atome451 wrote:That's what explained pBarrelas.
With a black and white texture (like an alpha or a grayscale bitmap) in the amount of your mixTexture or mixMaterial, you'll be able to do what you want.
With a mixMaterial, the white of the amount will show the material 1 and the black of the amount will show the material 2.
It's reversed for the mixTexture (i don't know why...): the black will show the texture 1 and the white the texture 2.

OF course, all intermediate greyscales between black and white will show an amount of the first and the second material/texture.

thank you very much, solved my problem!

Re: Stacking Materials

Posted: Wed Nov 05, 2014 12:24 pm
by aoktar
I like to do a explain about stacking materials. Why some features are hard to implement in our plugin?
Cpu renderers can do this much easier because directly can sample materials in their plugins.

But we have to create and store each materials and register to Octane engine. And we have to keep this copy until render session is active.
For stacking, we would have to create some complex mixed materials by assigned tags for each stacked assignment. And we have to keep this virtually created mix materials. I'm thinking about this for a while. Therocially that's possible, i like to spend some time to test it.

Re: Stacking Materials

Posted: Wed Nov 05, 2014 2:24 pm
by pBarrelas
Why not making a layer material, similar to the Mix material but up to 10 materials (as an example), where the mixing factor would be accessible next to each material entry by either using a float or a texture?

Re: Stacking Materials

Posted: Wed Nov 05, 2014 3:08 pm
by waterthinking
i am with NVN.. mix materials is not good enough; what if I have a piece of wood with a thick gloss coating? Stacking should be the way to go on an unbiased renderer imho. I find there is a lack of quality/realistic images on octane forum (compared to indigo/corona) that might have something to do with the shaders behaviour and or tonemapping (although hard to put the finger on it)

Re: Stacking Materials

Posted: Wed Nov 05, 2014 3:12 pm
by aoktar
pBarrelas wrote:Why not making a layer material, similar to the Mix material but up to 10 materials (as an example), where the mixing factor would be accessible next to each material entry by either using a float or a texture?
If i create a layer material, it could be done by mixing 10 materials. Octane have not layered material. This can be done virtually by plugi. But as i said on my previous message that, this kind of efforts is hacked way and can cause some problems on plugin. Also there is no any mixing filter.

Personally i prefer to wait a little about new improvements of Octane engine.