Material Preview Basic Inputs ContextInputs
Here you will find inputs for BDSF Nodes. To use more BDSF layers you can click on the Add button to add the desired number of ports. If you want to create an Emission or BSDF Node for a new port, you can click on the tiny drop-down menu next to the Add button.
The layers farther down make up the basis, levels farther up also lie farther up on the material’s surface. The order of the layers can be modified per drag & drop in the Attribute Manger.
Unused layers can be removed by clicking on the Remove button. Note that the BSDF Nodes linked with the respective port will also be removed.
The Copy and Paste buttons can be used to copy and paste selected BSDF layers. The Node connected with the respective input will not necessarily be copied.
For many of the effects described below you will find example images in the respective material channel descriptions (e.g., Transparency)
A material’s emission, i.e., its luminance or reflected light, can be created directly via a BSDF layer. Alternatively you can pass on color values directly to the material via this link. The luminance does not underlie the BSDF layer setup and will therefore always affect the surface.
In diffuse BSDF layers, colors with alpha can also be used. Enable the Layer Alpha option if you also want to control the visibility of the BSDF layer. The material can then be made transparent, even if no transparent properties were defined for the material. Without this option, diffuse BSDF layers will always be completely opaque, even if they contain an alpha component.
Parts of the material can be made transparent using brightness values. If the Alpha is white, the material will remain completely visible at these locations. If the Alpha is black, the material will be completely transparent. For grayscales in-between, corresponding transitions in opacity will be created.
If this option is enabled, additional settings will be made available with which the material’s transparency and refraction properties can be defined, e.g., for simulating fluids and glass.
The selected color will be used for the material’s transparency. Dark or heavily saturated colors will therefore lead to correspondingly less transparency than brighter or less saturated colors. The brightness of the selected color can therefore be used to reduce the channel opacity, comparable to the Opacity or Intensity settings of other channels. The Absorption setting is better suited for coloring fluids or glass surfaces since it does not affect the strength of the transparency.
Here you will find commonly used refraction indices of transparent materials such as glass or water – or even beer.
If you can’t find the material you’re looking for in the Presets menu, you can manually enter a refraction value here. The refraction index also affects the intensity of the reflection that is also calculated. Larger values will increase the reflective effect accordingly and will slightly darken the transparency. The distortion in the depiction of the transparency will also increase correspondingly. A refraction index of 1.0 corresponds to that of air at room temperature and will therefore not create any noticeable refraction or reflection. In combination with a slightly darkened transparency color and a reflection, this can still suffice for the simulation of a thin foil or a window pane that can be rendered quickly, e.g., for an architectural visualization.
As soon as a refraction ray hits a wall when glass is rendered, two slightly varied reflections can be rendered – the one that is produced when the ray enters the glass and a second reflection when it exits the glass. Visually, the one-time reflection most often looks better on the front surface, even if this is not physically correct. To avoid this, disable this option.
This setting defines the amount of dispersion within the transparency. The higher the values, the more the objects behind the transparency will blur – like looking through a sand-blasted pane of glass. A higher Roughness value will as a rule lead to correspondingly longer render times.
Fresnel Reflectivity [0..100%]
The defined Refraction Index will also be used for calculating a reflection on the transparency. Regions viewed perpendicularly will automatically be less reflective as regions viewed from a flatter angle. The Fresnel Reflectivity can be used to adjust the intensity of these reflections independent of their transparency.
This is the unit of measure for the refraction rays that are used by the Standard Renderer for roughness and matte effects within the transparency. The greater the number of rays, the softer and more noiseless the rendering will be – and the longer it will take to complete. If the Physical Renderer is used, this setting will not be applied since the quality of the rendering is defined directly in the Render Settings via the Blurriness and Shading Subdivisions settings.
This setting defines degree of Fresnel reflection on the transparency and can simulate a matte or rough surface. Increasing values can also lead to longer render times for the material.
This setting defines the color with which the light penetrating a material will be colored. This can, for example, be used in the simulation of colored fluids or glass without darker colors diminishing the transparent effect.
This setting defines the distance of a ray of light within the material from which the Absorption color should take over completely. If the ray of light covers longer distances within the material, the coloring of the light will be correspondingly more intense.
The shading of the surface is based on the orientation of the smoothed surface Normals. This setting can be used to affect the orientation of these Normals, e.g., to simulate irregularities or fine structures on the surface. As a rule, a Normal Map- or Bump Map Node will be linked here.
Unlike with Normal- and Bump-Mapping, the Displacement function actually deforms the object’s geometry by moving the surface points. As a rule, a Displacement Map Node will be used with which a corresponding texture can be linked.
Here you can define the maximum degree of deformation for the Displacement function. If this value is in fact reached depends on the RGB or brightness values contained in the displacement map.
Normally, the Displacement will only modify the position of existing polygon corner points. If an object only has very few polygons or if only a slight deformation should be created, the number of polygons and therewith the density of the surface points can be increased for rendering using the Sub-Polygon Displacement setting.
If Sub-Polygon Displacement is applied, this option can be used to also round the subdivisions added for rendering, comparable to the effect a Subdivision Surface object would have.
This setting defines the number of subdivisions that are generated by the Sub-Polygon Displacement function. The higher the value, the more detailed the result will be and the longer the render times will also be – and the more memory that will be required during rendering. Note that this value should be defined according to the object it affects. If, for example, you apply the same material to a cube primitive and a plane, the results will differ because the default cube has only six sides (polygons) and the Plane object has 400 polygons by default. The same applies for an object that has a very high local subdivision such as a character’s face, which will have many more subdivisions around the nose and ears than on its thighs, for example.
Internally, the following polygon count will be calculated per polygon:
- Triangle: (2 to the power of the level of subdivision) * (2 to the power of the level of subdivision) / 2
- Quad: (2 to the power of the level of subdivision) * (2 to the power of the level of subdivision)
A subdivision level of 8 would produce the following polygon count for rendering for the example above:
Cube: 6*256*256 = 393.216 polygons
Plane: 400*256*256 = 26.214.400 polygons
Always make sure you know the complexity of the respective model when defining a Subdivision Level and make sure the subdivision on the model is as uniform as possible so the Displacement function can also perform uniformly.