Download simple the mental mill shader here

The lerp (linear interpolation) node handles the mixture of the refraction and the reflection nodes. This mixture is controlled by the falloff node using using the fresnel function.

The comp_set_alpha node controls the transparecy of the shader via the alpha channel. Due to a bug in mental mill this isn’t functioning correctly.

Notice that the falloff amount of the falloff node and the alpha of the composite set alpha node are wired to the outside of the phenomenom and labelled as IOR and opacity. These will appear in the 3ds Max material editor with the amounts that are specified here as default.

Here is a mental ray rendered comparison with the A&D pro glass material in max 2010

As you can see the results are quite different. I was surprised to see that the shelled teapot renders much better with the simple glass mm shader than with the pro material. The solid teapot however is much more realistic using the pro glass.

Interstingly, the reflection on the ground plane has much better detail when using the simple mm glass shader on the teapot. The material of the ground plane is a default pro ceramic. You may notice the reflection of the teapots highlight is very bright in the foreground.

The shadows however suffer from being too dark when using the new shader. Something to work on.

While I was at EUE last week I had the pleasure of talking with Ruediger Raab and Neil Hazard who are partly to blame for this fantastic new viewport rendering in 3ds Max 2010. They both made presentations which included a section on using mental mill shaders with max and they highlighted the some ‘caveats’ and some work arounds that will help you to get your mental mill shaders 3ds Max.

1. contain your material in a phenomenon with a single output for the final node and a single output for the result.

Sounds complicated, but it’s not. When you finish a shader, group it into a phenomenon before saving it for use in max.

If the last node in the phenomenon has more than one output, for example like the illumination_phong then add one more node that has a single output, like a math_colour_add.

Also, make sure that there is only one output on the result of the phenomenom.

This will be fixed in later releases.

2. Express UV coordinates explicitly.

When you use a lookup texture node to load a texture you must assign it UV coordinates. Just wire a state_texture_coordinate node to the texture UV slot on the texture lookup node.

Ruediger suggested that we group this into a phenomenon and save this back the the mm palette for use whenever we need to use it. Good thinking.

3. Scene settings.

Access the scene settings from the render drop down menu;

render | scene settings

From here you can add light nodes from your mental mill palette and one environment shader. I’ve added three point light nodes and changed their intensity and colour.

I’ve then added the lights to the scene by clicking add light button in the scene settings dialog. You can then change the lights position. This is a process only undertaken by the adventurous as you may find it difficult to control. I’ve placed mine in a basic three point layout with a key light and two coloured lights, a warm one at the front right and a cool one lower and from the back. The lights help us see what the shader looks like in mental mill.

Finally I’ve specified the environment shader in the scene setting dialog using the environment shader drop down list. The environment shader will be used in the 3ds Max viewport to create faked reflections. When we render the scene with mental ray the reflections will be ray traced.

Now save this scene and use it as a template when you want to start a new mental mill shader. You can download this mental mill scene set-up from here

4. Mental Ray wont always reload the mental mill material when rendering in max.

There is scurrently a bug in mental ray that causes the renderer to re-use a cached version of the mental mill shader. If you change the mental mill shader in mm and reload it in max then your viewport and material editor should update. The problem is, that when you hit render then mental ray may use the older version it has in memory. You will need to force mental ray to reload the shader by either 1. re-starting max, or 2. saving the mental mill shader with a new name and re-selecting it in the DirectX material in 3ds Max.

Once you’re finished you can load the mental mill shader in 3ds Max 2010 and use the new viewport hardware shading to view your shader directly in the viewport. The autodesk guys have worked hard to ensure that this great viewport result is very close to the software rendering that mental ray does.

http://www.mentalimages.com/index.php

download the latest version and watch the introduction videos to get started.