The USD for 3ds Max 0.5 release adds full support for MaterialX to 3ds Max. You can load, import, edit, create, and export within 3ds Max using native tools.
So, what is MaterialX? According to https://materialx.org/, it is…
MaterialX is an open standard for representing rich material and look-development content in computer graphics, enabling its platform-independent description and exchange across applications and renderers.
MaterialX addresses the need for a common, open standard to represent the data values and relationships required to describe the look of a computer graphics model, including shading networks, patterns and texturing, complex nested materials and geometric assignments. To further encourage interchangeable CG look setups, MaterialX also defines a large set of standard shading and processing nodes with a precise mechanism for functional extensibility.
So, it is an open standard for material. It is a specification, an explicit set of requirements. Any renderer that follows this spec should give the same result for a MaterialX document. We could author a MaterialX material in 3dsMax/VRay, render in Maya/Arnold, and get the same result as long as we follow the spec. I’ll talk about it later again.
This update allow users to 1)Load MaterialX document 2)Render them with any renderer that supports Physical material/OSLmap(All CPU renderer and supported GPU renderer) 3) Edit the loaded material/maps 4)Author MaterialX material from scratch 5)Export as MaterialX document and 6)Export as material binding when export USD file. What do you need more than this?
Now why is MaterialX released as a part of USD for 3ds Max? This is because MaterialX is emerging as a material standard for USD. USD has UsdPreviewSurface. However, it only supports a very basic bitmap-based material tree without more advanced features such as subsurface and anisotropic specular highlights. Also, Material X has its own XML-based file format which goes along well with USD. USD loves files.
Let’s see how it actually works in 3ds Max.
Loading MaterialX
As I mentioned, MaterialX has its own file format, and the new MaterialX Material allows loading this .mtlx file.
As you can see, .mtlx file supports multiple materials in a file, and you can choose a sub-material from the dropdown.
OK, that was easy.
MaterialX Import/Export Utility(MtlXOIUtil)
Another way of bring MaterialX into 3dsMax is using the new MaterialX Import/Export Utility(MtlXOIUtil).
Press “Import MaterialX…” button and choose a .mtlx file. Then, the MaterialX materials are imported and assigned to the selected objects.
If you have not selected objects or selected less objects than materials in the file, this utility will automatically created teapots and assign the imported materials on them.
If you choose a material library file(.mat) and check “Add to Material LIbrary”, imported materials are stored in the material library. They will be imported(exploded), Physical material not MaterialX material.
“Populate Material Editor” will put imported materials in the material editor slots.
Editing MaterialX
MaterialX in 3dsMax is implemented using Physical material and OSL maps. I heard that one of the reasons for adding OSL map support to 3dsMax was actually part of the grand plan for this initiative.Therefore, you can edit MaterialX material tree just like any other 3dsMax materials/maps using CME or Slate. This also means that any third-party renderer that supports 3dsMax Physical material and OSL map will be supported automatically.
MaterialX material provides 2 ways to edit the material tree.
- Explode Permanently – Pressing this button will convert the MaterialX material to Physical material + OSL map setup. The MaterialX file loader material will disappear from Slate and the new Plysical material will be assigned to the objects.
- Open for Edit – Pressing this button will make a new tab with the Material node name(Not the MaterialX file name. The 3dsMax Material name) and put exploded material tree there. As you can see, the MaterialX material is still assigned to the objects(the white triangles around the corners show that). But, any changed on the material tree in the new tab will be applied to the objects.
Authoring MaterialX
If we can load and edit a MaterialX shader tree, well, that means we can make one from scratch, too. I mentioned any renderer that supports MaterialX will give us the same result for Material materials as long as we follow the spec.
MaterialX certainly can do more than bitmap-only-based PBR material. It has a bunch of Standard Library Nodes, and 3dsMax MaterialX supports them. Would this set of nodes cover all your production needs? Well, see for yourself. Here is the spec document. You will probably need to sacrifice the flexibility and features for compatibility. “Standard” always means the least common denominator. It will never be the best of all. But, When you need it, you will need it. Having good comprehensive support for such an open standard is a good thing.
Let me say it again. A material standard only works when you follow the standard exactly. Even one parameter difference in the shader tree can make totally different result. Some might want to have an automagic converter for all our 3dsMax maps and 3rd party maps. But, doing that will open a can of worms. I rather have a clear explicit way to author MaterialX when I need MaterialX.
As I mentioned, this MaterialX support is implemented by Physical material + OSL map combo. Therefore, only Physical material is supported for the material. The good thing is that most 3rd party renderers support Physical materials which means they will get MaterialX support automatically.
For maps, there are MaterialX maps category under OSL. You can find 1:1 MaterialX Standard Library Nodes here.
Here are a few things you need to know.
- 3dsMax “Normal Bump” can be used for MaterialX “normalmap”
- Each data type has its own map. For instance, there are 4 “acos” maps for float, vector2, vector3, and vector4. This may seem tedious, but in my experience, it actually makes it much clearer which data type I am currently working with. If you use the wrong data type, MaterialX will simply not export those invalid trees.
- Make sure to use “color” type for color. Never use “color” type for data. All color-type maps will be color-managed. This means you can’t load a map and use it for baseColor and Roughness. You must use 2 separate texture nodes to load one as color and another as data.
- Bitmap material is supported. But, only the filename will be used. If you want to adjust tiling and offset, use “mx_image” or “mx_tiliedimage” maps.
- If you want to know what each map does, check the MaterialX spec document.
This is what I made in 3dsMax using Physical material and
And loaded in QuilitiX
Hers is another good news. 3dsMax has a few specialty materials that use Physical material under the hood. If you use any of these materials, you can exported them to MaterialX.
- PBR Material (Metal/Rough)
- PBR Material (Spec/Gross)
- glTF Material
- USD Preview Surface Material.
Exporting MaterialX
You can export the new/edited materials using MaterialX Import/Export Utility(MtlXOIUtil). Just select objects with materials to export and Press “Export MaterialX”
If there are multiple materials in the selection, all those materials will be stored in a .mtlx file.
Make sure to check Maxscript LIstener for validation checks. Your material tree might not be valid. If you see warnings, you must fix them to export properly.
Integration with USD
The MaterialX plug-in comes with a Shader Writer for the 3ds Max USD Plug-in that will allow the USD export to bind references to the MaterialX files to USD Prims when exporting scenes using a MaterialX Material.
Here is a short video of MaterialX in 3dsMax in action.