Smart Materials are assemblies of layers that conform, adapt and react to the underlying surface and geometry. This also gives user the ability to quickly and easily “style swap” 3D assets by applying existing or saved smart materials on other 3D assets, giving consistent results that will fit together harmoniously in a scene, and ensuring the user can get the most use out of their assets.
Every Smart Material can be tweaked. This means adjusting reflectance values, masks with curvature, ambient occlusion, noises and switching out textures plus a lot more allowing you to achieve a truly custom look and feel.
How To Use Smart Materials
Using a Smart Material in your project is as simple as dragging and dropping or by just clicking on the smart material. This will place the selected material above the highlighted layer in the layer stack which can be rearranged at any time. They are treated just like regular library assets – just smarter.
From here, you can go into any of the layers and their associated masks within the Smart Material and adjust them as much as you’d like. Changing curvature, imperfection, noise or channel data is all possible still, and these can also be re-exported as a new Smart Material if desired.
Open Smart Material as a Mix
You can load a smart material from the library as a Mix. This will load a shader ball textured with the smart material selected. You can modify the smart material further according to your requirements and then save it as a new smart material.
Your Smart Materials should be designed with performance in mind. This means utilizing pre-existing textures either from the Megascans library (such as imperfections) or linking to the channel of a specific layer within the Mask Stack. Although Mixer 2020 does have the ability to use procedural noises, the use of physically-accurate scan data ensures you get the highest quality possible. There is no right or wrong choice here, just remember to optimize where you can.
How To Make Smart Materials
Creating a Smart Material is as simple as placing all your desired layers into a group. This then allows the Mix to be treated as a single smart layer. Please read Making your first 3D Mix to get up to speed with setting up a base Mix to be used for a Smart Material.
To convert this, highlight all of the layers you would like within the smart material by holding Shift + clicking layers to select multiple layers at once, or CTRL + clicking to select individual layers.
Once highlighted, you can then click the folder icon at the bottom of the layer panel, next to the masking buttons. Alternatively, you can use the hotkey, CTRL + G. This will add the selected layers to a group.
The name of the group will generally be the name of your smart material, so giving it clear representation of what the material is will help you in the future. However, you also have the option to set the name of the Smart Material when saving as well.
Alternatively, if you have a pre-existing group set up with layers already inside, you can drag and drop additional layers within the group. These will then be a part of the Smart Material once saved.
Imperfections/ Library Assets
Within the Image Mask layer in the Mask Stack, you can now load in assets from within the Megascans library to use in your masks. Clicking ‘Browse Library’ will take you to your Local Library, where you can then pick an asset.
This also allows you to choose which channel you would like to reference. For example, selecting a Scratched Painted Metal from the library would allow you to use any of the channels that come with that asset.
In the example above, an imperfection asset is loaded, and the blending is set to overlay which greatly improves the look of the mask. All this while not requiring much computation at all when compared to a fully procedural alternative.
In this example, the Layer Map option is chosen. This then allows a layer to be selected and shows what channel the Image Mask layer should reference. In this case, the Gloss channel of the_ Painted Gun Metal Layer_ is chosen. As before, the layer was set to Overlay, but this time the range slider was adjusted to help get a better result by tightening the levels of the mask.
Reusing and referencing assets like this saves on performance, as nothing is in need of being mathematically computed behind the scenes. This may not have much of an effect when dealing with one or two Smart Materials, but on larger projects, this ensure fluid use.
You can add a custom image to your Mask Stack as shown above. Any existing custom images imported elsewhere within the project will also appear within the drop-down to be re-used as needed. The usual control exists for this layer type.
Saving Smart Materials
Once your smart material is set up and you’re ready to save it out, it is as simple as right-clicking on the group housing the material information, and selecting Save Smart Material. Once again, ensure your group has a name relevant to the type of material you’re wanting to create if prompted.
Your smart material will now be visible within the Local Library. The asset type drop-down can be used to select Smart Material to only show those assets.