MIA Material - Basics

From TOI-Pedia


This page will guide you through setting up a basic mia material. The influence of changing the different mia material properties that were described in MIA_Material - Background Information will be illustrated with different examples.

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 and high-quality glass.

This tutorial covers how to create MIA materials in the Hypershade, how to apply it to the object in your scene and how to change the basic parameters and advanced parameters of the material.

MIA materials can only be used when rendering using Mental Ray.

Making Materials

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The Hypershade

The interface we use to create, edit and assign materials is the Hypershade. You can find the Hypershade by going to Window » Rendering Editors » Hypershade.

The Hypershade is divided in two main parts. In the top part you see an overview of all the materials that are in your scene, the bottom part is the working area. On the left side of the hypershade you see shortcuts to create different kinds of materials.

Finding the Hypershade
The Hypershade

Creating and editing a new MIA Material

In order to create a mia material, you have to open the mental ray section at the right.

Before Maya 2011: switch to 'creating mental ray nodes' in the drop-down menu in hypershade where it says 'create maya nodes'.

To find the mia materials, open the first submenu Materials there and then choose mia material x. Mia materials can also be found under Create » mental ray Materials » mia_material_x.

Open the mental ray section. If this section is not available, you have not loaded the required plug-in. To solve this, go to the Mental Ray page and see under "common problems".
Create a mia_material_x
Objects with mia_x

The attribute editor

Choosing mia_material_x will automatically generate a reflective, grey material that appears in both the upper (material library) and the lower part (work area) of the Hypershade.

In order to change the attributes of this material, double click on it and the attribute editor will appear. Depending on your settings it will either open in a separate window or it opens at the righthand side of you main Maya window.

In the first field in the attribute editor you see that the name of the material is mia_material_x1. You can change it to make it easier to recognize, eg: 'mia_concrete' if you are going to make a concrete material.

Mia material not supported by current render engine.jpg
mia_material or other mental ray nodes in the hypershade may have a red background. This indicates that the render engine that is currently selected in the Render Settings, does not support this shader. You may ignore this warning when creating your materials. It will disappear automatically as soon as you select mental ray as your render engine.

Assigning the material to geometry

When you're satisfied with your material you can assign it to the faces of your geometry. You can either select an entire object by selecting it or just a face by going to component mode and selecting just one of the faces of an object, then go back to your hypershade, right-click on the material and release above assign material to selection:

MR mia assignmaterial.jpg

Changing basic parameters


With diffuse, you can change the color of the object. You can do that by clicking on the grey area next to the text color in the diffuse section and choosing the right color in the color palette. Diffuse weight and roughness can be changed by using the sliders.

Changing the color
Color changed to green
Changing weight and roughness with the slider


To adjust the reflection you adjust the values of the reflectivity and the glossiness with the slider. By adjusting the reflection we change how much light is reflected (the higher the value, the more reflected light). By adjusting the glossiness we change how sharp or blurry the reflection is (the lower the value, the blurrier the reflection, a value of 1 means no glossiness). The color of the reflection can be changed by clicking on the color square, the 'greyness' by changing the slider next to it.

Changing the reflectivity and glossiness with the sliders
Change the color to yellow
Reflectivity color changed to yellow
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Refraction (transparency)

If the material will have to be transparent, the transparency will have to be changed. By increasing the value of the transparency the material gets more transparent, by adjusting the glossiness the reflection looks more or less blurry.

Changed transparency
Changed (low) refraction
Changed high refraction
All attributes (except color) are changed with the sliders
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If you want to achieve the effect of making a part of your object transparent, see below at "cut out".

Changing Advanced parameters

Ambient Occlusion

An option you can use is the ambient occlusion. With the ambient occlusion contact shadow is calculated and rendered. This will give the render a better sense of depth. To turn it on check the use ambient occlusion box. The distance determines how near the geometry has to be to influence the contact shadow.

Setting up ambient occlusion
Without ambient occlusion
With ambient occlusion: darker, more realistic shadows
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A detailed tutorial about setting up ambient occlusion can be found here. It includes how to set up a separate render pass with a surface shader - which means rendering ambient occlusion once in order to combine it with your final render in Photoshop to save render time.


Bump makes it seem as if your object has a relief even if it does not: the light will be reflected off it as if it is not flat while its structure has not changed. In the practical example below, you can see that you can see how to make brick with seams, but that the edges of the cube remain smooth.

The bump option can be found in the attributes of your material. here, you can apply a file or procedural texture to the Overall bump by clicking on the checkered box next to it. From the images/procedurals that you couple to the bump, the white areas will come forth and the black areas will seem as if they are indented. You can change the Bump Depth to increase the "distance" between black and white.

This is the pattern that will be coupled to the bump
The white areas seem to protrude, the black ones to recede
Increasing the Bump Depth

Additional color

An area light is lighting the scene
The light source is not visible in the render

When making a light in maya, it does not have a “source”. When making a lamp, however, one wants it to seem as if an object actually gives off light. The same for windows of buildings at night: the window panes should look as if they give off light.

The option additional color at its default
The torus has a mia_x material without reflectivity and additional color at 0 (black)
The same object with a light green additional color

One can achieve this effect with the additional color attribute of the mia_x material. It can be found under the Advanced tab and is normally black. Then a material gives of no light. When clicking on the black, the color picker appears. Underneath the color wheel, three sliders H, S and V can be seen. The value related to if the material will give off light is V. If a color is chosen, one can see that the object gives off some (colored) light.

Choosing the brightest option on the slider
White as additional color
Raising the V value to 100
A higher V value makes the object give off more light, but it is not enough to be a light source even with high final gather settings

1 (white) is the highest option for the V slider. The object glows, but does not give off a lot of light. The slider seems to be at its maximum but we can manually enter a higher number, for example 100. The additional color is now “whiter than 1” and the object gives off more light. For acting as a light source, it is not enough however. As you can see above, even with high Final Gather settings, the image seems blotchy. Thus it is better to create a light, and with employing the light emitting texture, make an object that acts as its "physical source".

For a practical example of setting up a light emitting texture, you can take a look at this tutorial about making a light bulb for a lamp post.

Cutout Opacity

Cutout opacity is useful if one wants to remove parts of an object without actually making a hole in the object itself. The option can be found under Advanced. A practical example for adding cut out objects to your scene can be found under: Mia Material - Practical Examples.

Cutout opacity at 1: the material is visible
Cutout opacity at nearly 0: the material becomes invisible
Cutout opacity at nearly 0
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