Base Shader Mia Material X

Maya, Mental Ray: Materials

This page is depricated. The new MILA shader (2015 onwards) now replaces the miaMaterialX. However there are a lot of similarities and this page can be helpful regarding the MILA material as the older miaX is very similar.

In particular see the autodesk page on the MiaX which breaks down the components of the material, the MILA’s components are almost identical.

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The mia_material_x, is the main shader inside of Mental Ray used on most surfaces. From the Autodesk website….

“The mental ray mia_material is a monolithic material shader that is designed to support most materials used by architectural and product design renderings. It supports most hard-surface materials such as metal, wood and glass. It is especially tuned for fast glossy reflections and refractions (replacing the DGS material) and high-quality glass (replacing the dielectric material).”

The only surfaces it’s not commonly used for is, car paint (which we use the mi_car_paint_phen_x or mi_metallic_paint_x1 and subsurface scatter which I prefer the misss_fast_shader2_x)

For full details about this shader see the offical mia material page here…

Autodesk’s Breakdown of the MiaX

It’s a good idea to really study the attributes involved in the mia material to tweak the type of look you’re after.

Also remember that you can often download many mental ray shaders from the following pages below. Shaders can be saved out of the hypershade with the menu

(Hypershade) File > Export Selected Network

And imported with

(Hypershade) File > Import

Main AREAS OF THE MIA MATERIAL X

Like everything inside of mental ray there’s a lot of dials and switches to get to know. However the most commonly used areas of the shader are as follows.

Presets
Top left hand corner, allows you to select some commonly used presets with pre made values. Pick a shader that most closely resembles what you’re after and tweak from there.

Diffuse
Color: The most important attribute here is the colour which governs the main colour of the shader if it’s diffuse is set to high. Remember to gamma correct swatches for linear workflow.

Weight: This governs how much colour will come out of the shader. For most objects this will be set very high, .8 to 1. Some shaders such as copper and heavy metals get most of their colour from reflections etc so they have a low diffuse weight.

Roughness: Roughness will give the shader a more powdery type of effect. the rubber preset has a high roughness for example. Most presets will have lower values.

Reflection (specular)
Because the MiaMaterialX shader is physically correct, the reflection section covers both reflections and specular.

Specular is often more efficient to separate by itself to save the render hit of true reflections. If you wish to use specular without the render hit of true reflections you can check the box “Highlights Only”, that will disable reflections.

Color: Is the colour of the reflection
Reflectivity: Is how reflective the object is
Glossyness: Reflective blur if highlights only checked off… also is the specular sharp (high values) or broad (low values)
Glossy samples: Increase this when the shader is showing signs of noise.
Highlights Only: Disables Reflections and just shows specular
Metal Material: Uses the diffuse color as the reflection colour

Please note: for reflection BDRF needs to be tweaked under the BRDF section
BRDF is the incidence of reflection, set the min value up to 1 if doing a mirror for example.

Transparency
Transparency channel is hard to find, it hides under the “Refraction” section

Bump
We can assign both bump and normal maps to this shader (displacement is set elsewhere). This is easy to do and you can use either of the slots.

Overall Bump
or
Standard Bump

They can add together. It’s common to use the Standard Bump slot that way the Overall bump is kept in reserve.

No Diffuse Bump: Will add the bump only to the specular/reflection attributes not the diffuse channel. You leave this off in most situations.

MENTAL RAY SHADER DOWNLOADS

MATERIAL PRESETS

Below are examples of the material presets. take note of the render times with each preset varies depending on the attributes and types of rendering assigned.

Typically the following factors will increase render times

Reflections
Blurring Reflections (more so)
Refractions (more so)
Translucency
Caustics ( a lot)

etc

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