Layered Material-层材质

Layered Material

The OctaneRender® Layered Material system allows you to construct a complex material that consists of a Base Material, with a maximum of 8 layers that can be inserted on top of the base layer. We separated and exposed a set of layers (Diffuse layer, Specular layer, Metallic layer, Sheen layer) that made up the complex materials from previous Octane versions (Diffuse material, Glossy material, Specular material, Metal material, Universal material). Using this set of unique layers, Octane now empowers you to recreate complex materials in a physically based manner as opposed to manually mix materials together.

LAYERED MATERIAL EXAMPLE

As an example, below we have a generic phone screen with a material built from a diffuse emission layer as the Base Material, a diffuse, black material as a mask layer for the black non-emissive areas for Layer1, then a specular layer to provide the overall gloss on top, with a smudge map in the roughness, for Layer2:

RAINDROP EFFECT USING PER LAYER BUMP MAP AND NORMAL MAP PERTURBATION.

This example consists of two specular layers, with the top specular layer using a custom raindrop normal map while the bottom (the Base Material’s specular layer) uses the geometric normal. In order to use a different IOR for the water (without affecting the glass), we used an alpha map for the raindrop layer’s Layer Opacity to isolate any layer attributes to only the drops:

BE BANKSY WITH LAYERS

With the Layered Material, you can layer decals on top of your Base Material (or build in reverse). Consider this spray painted rocky wall as an example. It can be built in many different ways with the Layered Material; here we used a specific approach — we created the glossy material as the Base Material (the spray paint). We used masks in Layer1 (the rock layer) to allow the spray paint to show through, giving it the appearance of being on top. As a bonus, we can use a displacement in the base layer that will also make the layers on top appear as though they are displaced as well.

As mentioned, you can achieve this look in many different ways, for instance: create your rocky wall as the base diffuse or rough glossy material, create your diffuse spray paint material as Layer1, then add a specular material on top of all the layers in your Layer2 input and use your spray paint mask in the Layer Opacity.

CREATING ROCK WITH LAYERS

In the following example, our Base Material is the underlying dry portion of the rock, our Layer1 material is a darker diffuse material version of the same rock texture, and our Layer2 material is merely a specular to overlay a shiny wetness. Both our Layer1 and Layer2 are masked with a gradient in the Layer Opacity inputs so that the darker material is confined to the lower portion of the mesh, and reusing that same gradient, we can make just that portion shiny and wet in appearance. The displacement and normals only need to be used in our Base Material:

CREATING CAR PAINT

With the Layered Material you can easily craft materials in the same way they are constructed in the real world. In this example we created a car paint material. There are quite a few ways to do this, but in the simpler example here, we’ve used the metallic Base Material with color driven mainly from the specular channel, and a bit of roughness. A flake normal map was placed into the Base Material to produce the metallic flake. After that, we added a clear coat with a specular material in Layer1:

LAYER GROUPS

Layer groups can be used to further organize and re-use of relevant parts of a node graph. There are two ways to create Layer group nodes:

• Drag from input pin of a Layered Material and use the node search window, explained here. Double-click “Material layer” from the node list. Select the node, and in the attribute panel, choose, **Layer tab > Layers > Add**, and choose Layer group from the list. Select that new Material Layer node and then choose Add again, this time picking the desired material type. This will create a new Layer input in the Layer group node, as well as a new material layer of the type selected, already connected.

• Drag a Material layer node from the Texture Group in the node editor. Select the node, and choose Add, Layer group from the attribute panel. As with the previous method, this will convert the Material layer node into a Layer group. Select that node and choose Add again, adding a desired material type, which will automatically make the connection.

In following example, we show a how to use Layer nodes to build a more complex Layered Material. We have created a Layer Group node that works together with the Layered Material for simpler grouping of material layers to help sharing of layers between materials. In the example, we’re using a glossy Base Material with a smudge texture in the roughness channel. In the Layer1 input, you’ll see we’re using our Layer Group node where we’re combining a diffuse orange layer with a specular layer (for gloss) into one node, masked with the OctaneRender logo: we’ve done all this while only using one input on the Layered Material, leaving another input open for extra details. For our Layer2 input, we used a metallic layer masked with a simple square frame. Now the metallic is only revealed in the white areas of the mask on the mesh.