Materials Editor Panel

This is probably the most important panel in Koru. Here you can configure materials to make your scene looking the way you need. Here’s what it looks like:

Koru materials editor panel

The panel consists of three blocks:

  • Material preview - the area where you can see the currently edited material rendered on a standard shape;
  • Material tree - here you can find the tree of groups and layers that make the material;
  • Parameters - the rest is the parameters of the currently selected item in the material tree.

Materials editor displays the properties of the currently selected material. You can select material by clicking an object in the scene, or directly in the scene materials list. The name of currently selected material is displayed in the panel title, so you always know what you edit.

Material Structure

It is described in more details here, but in two words materials consist of layers. Koru draws material layer by layer to render a surface.

Materials editor displays these layers in the material tree. By clicking items in the materials tree you see their properties at the right (or at the bottom for the narrow panel).

Main Parameters

Here you define if the material is single or double-sided. This affects culling and needs to be adjusted if geometry looks invered.

Material Layer

Layers are the objects that actually define material. See here for more details on how they work, here we’ll briefly run through all the properties.

Each layer can be emissive, diffuse or specular (or both). You activate the parts of the layer with check boxes in material editor. Each part has its own settings described below. There are also some common settings that works regardless of the layer’s type:

  • Mask - helps you show and hide various parts of the layer. White mask means “show this”, black mask means “hide this”, gray helps to make layer partially visible;
  • Bump - that’s a simple normal-based bump

Then goes Diffuse layer check box that toggles diffuse properties panel:

  • Color - controls the color of the diffuse part of the layer;
  • Opacity - controls the transparency level of the diffuse part;
  • Transparency is mask - if enabled, the alpha-channel of diffuse texture is used as a layer mask. This is convenient for semi-transparent decals, labels and so on.

The Specular layer check box lets you configure the reflective options of the layer:

  • Reflection - controls the reflection tint of the layer, it basically colors up the reflection;
  • Transmission - controls the refraction tint of the layer, coloring the underlying parts of the layer;
  • IOR - lets you choose how to setup reflection and refraction properties of the layer. You can choose between scalar and complex index of refraction and providing a measured data file for the material;
  • N, K - scalar and complex parts of the index of refraction;
  • IOR File - lets you load a file with measured parameters of the layer refraction;
  • Reflection 90 Level - defines how much of reflected rays look different if reflected by the right angle;
  • Reflection 90 - provides an alternative reflection color and image for right angle reflections;
  • Roughness - controls the reflection blur of the layer, the more rough (uneven) the layer, the blurry the reflection;
  • Anisotropy - controls the level of anisotropy effect;
  • Angle - controls the direction of anisotropy (angle), works best with a proper texture, Koru has some in the materials library.

You can also add an optional thin-film interference effect to reflecting material (think of soap bubble, oil on water or color-coated sunglasses). Check Thin-film interference box to see these extra options:

  • Thickness - the base thickness of the thin layer (measured in nanometers);
  • Min Thickness - activates if the Thickness parameter gets a texture, so the Min thickness becomes the minimum value, while the Thickness values are added to it;
  • IOR - lets you select the way Koru computes interference. The options are: Scalar, Complex and Measured data.
  • N, K - scalar and complex parts of the index of reraction
  • IOR File - lets you load a measured data file for the thin-film layer;

Finally, there is Emissive layer section that lets you make materials emissive. The options are quite straightforward:

  • Color - defines emissive color;
  • Level - controls the level of emission.