The Settings Window for Material
The Settings window for Material () summarizes the predefined or user-defined material properties for a material. This is where you can add or change material properties to fit your model and assign the material to all types of geometric entities: domains (most common), boundaries, edges (3D models only), or points. Also see Material Link and Switch for Materials.
After adding a material (see The Add Material Window and The Material Browser Window), click the Material node (for example, Material 1 or Copper) in the Model Builder. The Settings window for Material opens.
A standard Material node in the global component can turn into a layered material by adding a Shell property group. After that, it can be linked by a Layered Material Link
In the Label field, enter a suitable label for the material. If you defined global materials for a user-defined material library, the label becomes the name of the material. See also Material Library Settings below. You can also use the Name field to change the identifier. This setting also changes the tag and therefore makes it possible to control the scope of variables and functions that the material defines.
Figure 9-6: Click the Copper node to open the Settings window for Material for the node.
Geometric Entity Selection
This section is available for materials in a component. Assign the material to some or all entities on a specific Geometric entity level — Domain, Boundary, Edge (3D only), or Point — on the geometry in the Graphics window (the geometry in the model). The icon for the Material node indicates the geometry level. For a 3D component, for example, the following icon overlays represent the domain, boundary, edge, and point level, respectively: , , , and .
By default, the first material in the Component is active in all domains (or all boundaries or edges if the Component only contains surfaces or edges). By assigning other materials to some or all domains, the first material is overridden and remains active only in domains where no other material, added below it in the Materials branch, is active.
If the Component contains features on different geometric entity levels, such as solid mechanics in domains coupled to beams on edges, and the features use the same material, you need to add two Material nodes with the same material, one defined in the domains, and the other defined on the edges.
Override
This section, available for materials in a component, shows if the material, in some or all parts of the geometry where it is active, is overridden by another material added underneath it in the Materials branch, or if it overrides another material above it.
The Overridden by list shows the names of the materials that override this material. The Selection list in the Geometric Entity section displays (overridden) for the geometric entities in which this material is overridden.
The Overrides list shows the names of the materials that this material overrides.
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Physics Exclusive and Contributing Node Types
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Physics and Variables Selection
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Physics Node Status
Orientation and Position
This section only appears in Material nodes that are single layer material. See Single Layer Materials.
Select a Coordinate system defining the principal directions of the laminate. Only Boundary System coordinate systems can be selected.
Choose a Position — Midplane on boundary, Downside on boundary, Upside on boundary, or User defined. This controls the possible offset of the material from the geometrical boundary on which the mesh exists (the reference surface). For User defined, enter a value for the Relative midplane offset. The value 1 corresponds to Downside on boundary, and the value −1 corresponds to Upside on boundary. Values may be outside the range −1 to 1, in which case the reference surface is outside the laminate.
The Position setting is only used by physics features where the physical behavior depends of the actual location, such as structural shells.
By clicking the Layer Cross Section Preview () button, you get a preview plot of the single layer material, including the location of the reference surface. This plot looks similar to Figure 9-12, but there is only a single layer. You can also click the downward pointing arrow to choose Layer Cross Section Preview () button or Create Layer Cross Section Preview () button, which adds the preview plot as a new plot group under Results.
Material Properties
You can add material properties to the material if they are not already included. To do so, browse the available material property categories (Basic Properties, Acoustics, and so on), and select a material property or a collection of material properties in one of the property groups or material models that appear under the main level of material property categories. Right-click the material property or property group and select Add to Material, or click the Add to Material button () to add the material property or group of properties to the material.
Review the properties listed in the Material Contents table before adding new material properties.
For example, under Acoustics>Viscous Model select Bulk viscosity (muB) and right-click to Add to Material or click the Add to Material button (). If you add a material model like the Viscous Model with more than one property, all of its material properties are added to the Material Contents table. In this example, a Viscous model node is added to the Model Builder and its associated properties are added to the Material Contents table.
To delete a property group, right-click the property group node (in the Model Builder) and select Delete (). The Basic property group cannot be deleted.
A Note About Adding Basic Material Properties
Material properties can be added to the Basic group or to any User-Defined Property Group from two locations — the Settings windows for Material and Property Group.
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When material properties are added from the Basic node’s or a user-defined group node’s Settings window for Property Group, they are listed under Output Properties and Model Inputs in that Settings window.
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When material properties are added from the Settings window for Material, the available material properties are listed under Material Properties and are added to the list under Material Contents with the property group listed. The list under Material Contents also contains material properties added from a subnode with a Settings window for Property Group.
Material Type
The Material type setting decides how materials behave and how material properties are interpreted when the mesh is deformed. Select Solid for materials whose properties change as functions of material strain, material orientation, and other variables evaluated in a material reference configuration (material frame). Select Nonsolid for materials whose properties are defined only as functions of the current local state at each point in the spatial frame and for which no unique material reference configuration can be defined.
Simply put, Solid materials associate material properties with specific pieces of the material, and the properties follow the material as it moves around. In particular, a solid material may be inherently anisotropic, meaning that its axes rotate together with the material. The Nonsolid choice, in contrast, applies typically to liquids and gases whose properties are associated with fixed points in space and insensitive to local rotation of the material. Such materials are inherently isotropic when studied in isolation but can exhibit anisotropy induced by external fields. In practice, this means that any anisotropic tensor properties in a nonsolid material must be functions of some external vector field.
Material Contents
This section lists all of the material properties that are defined for the material or required by the physics in the model. The table lists the Property, Variable, Value, and Unit for the material property as well as the Property group to which the material property belongs. The Property group corresponds to the subnodes in the Model Builder with the same name. If required, edit the values or expression for the property’s Value.
The left column provides visual cues about the status of each property:
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A stop sign () indicates that an entry in the Value column is required. It means that the material property is required by a physics feature in the model but is undefined. When you enter a value in the Value column, the material property is added to its property group.
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A warning sign () indicates that the material property has been added to the material but is still undefined. An entry is only required if the material property is to be used in the model.
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A check mark () indicates that the property has a Value and is currently being used in the physics of the model.
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A synchronize symbol () indicates that the property is computed and synchronized using the given values for other material properties from which it can be computed.
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Properties with no indication in the left column are defined but not currently used by any physics in the model.
You can change the value for any property that is not synchronized by editing its value directly in the Value column, or, for a selected property, click the Edit button () or right-click and choose Edit to enter a value in the window that opens. If the property can be anisotropic, you can choose to enter the values in one of these forms: Isotropic, Diagonal, Symmetric, or Full. The Variable column lists the variable names corresponding to the degree of anisotropy. For example, for a symmetric electrical conductivity, it contains {sigma11, sigma12, sigma22, sigma13, sigma23, sigma 33}; sigmaij = sigmaji. For an isotropic electrical conductivity, it contains sigma_iso; sigmaii = sigma_iso, sigmaij = 0, where sigma_iso is the name of the variable for the isotropic electrical conductivity (available as, for example, mat1.def.sigma_iso).
You can right-click any defined material property in the table and choose Go to Requesting Node; the focus in the model tree then moves to the node that requested that material property. If there are more than one node that requests that material property, a Go to Requesting Node dialog box appears, where you can choose which of those nodes to go to. Also, for nodes such as Material Link and Layered Material Link, you can right-click any defined material property and choose Go to Source to move to the material node that is the source of that material property.
Material Library Settings
Select the Material Library Settings check box in the Show More Options dialog box to display this section for Material nodes under Global Definitions.
In this section, you can define properties for materials in a user-defined material library to create a set of materials with varying material phase and orientation or variation.
Click the Update the Label button () to update the label, which becomes the name of the material in the user-defined material library.
From the Phase list, choose Custom, Solid, Liquid, or Gas to define the material’s phase. This setting is not available if the parent Group node has its Group type set to Phase and orientation, in which case the phase is defined in that Group node’s settings.
In the Orientation/variation field, enter some orientation or variation that represent this material.
Appearance
The settings in this section, available for materials in a component, make it possible to control or change the default appearance of a material in the Graphics window when working in the materials or physics parts of the model tree.
In 3D components, the material is rendered including color and texture when Scene Light is active. In 2D models and in 3D components, when Scene Light is turned off, only a change of color is visible.
The Material type list provides quick settings approximating the appearance of a number of materials — Air, Aluminum, Brick, Concrete, Copper, Glass, Gold, Iron, Lead, Magnesium, Oil, Plastic, Rock, Soil, Steel, Titanium, Water, Wood, and more. Select Custom to make further adjustments of the specific settings for colors, texture, reflectance, and so on. The default custom settings are inherited from the material selected last from the Material type list. If you have chosen a family other than Custom, click the Customize button to define a custom material.
Specular Color, Diffuse Color, and Ambient Color
For each of these properties, select a standard color from the list: Black, Blue, Cyan, Gray, Green, Magenta, Red, White, or Yellow, or choose Custom button to define a custom color from the color palette that becomes available underneath the list of colors.
The combination of Specular color, Diffuse color, and Ambient color gives a 3D object its overall color:
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Specular color is the color of the light of a specular reflection (specular reflection is the type of reflection that is characteristic of light reflected from a shiny surface).
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Diffuse color represents the true color of an object; it is perceived as the color of the object itself rather than a reflection of the light. The diffuse color gets darker as the surface points away from the light (shading). As with Ambient color, if there is a texture, this is multiplied by the colors in the texture, otherwise it is as if it has a white texture.
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Ambient color is the color of all the light that surrounds an object; it is the color seen when an object is in low light. This color is what the object reflects when illuminated by ambient light rather than direct light. Ambient color creates the effect of having light hit the object equally from all directions. As with Diffuse color, if there is a texture, this is multiplied by the colors in the texture; otherwise, it is as if it has a white texture.
For examples of specular, diffuse, and ambient light, which are related to these definitions, see About the 3D View Light Sources and Attributes.
Custom Basis for Brush Lines
Select the Custom basis for brush lines check box to define a custom coordinate basis for the brush lines. The default values for the brush line axes represent the global Cartesian coordinate system. Specify other x, y, and z coordinates for the Origin and the xm-axis if desired. To specify other coordinates for the ym-axis, first select the Specify ym-axis check box.
Normal Mapping
Select the Normal mapping check box to add normal vector noise and brush lines. Normal mapping is a texture that disturbs the normals when calculating lighting on the surface (also called bump mapping). This causes the surface to look rough and textured. The default Normal vector noise scale and Normal vector noise frequency are taken from the material. You can choose the type from the Noise type list: White noise (a uniform distribution) or Simplex noise.
Enter other values as needed, or click to clear the Normal mapping check box.
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The Normal vector noise scale is the power of the noise texture. A high value creates a stronger texture of the surface. A value between 0–1 is suitable.
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The Normal vector noise frequency is the size of the noise disturbances. A small value creates smaller features on the texture. A value between 0–10 is suitable.
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Add brush lines if desired by choosing an option from the Brush lines list: No brush lines (the default), Brush lines orthogonal to xm-axis, Brush lines orthogonal to ym-axis, Brush lines orthogonal to zm-axis, Brush lines along xm-axis, Brush lines along ym-axis, Brush lines along zm-axis, Brush lines around xm-axis, Brush lines around ym-axis, Brush lines around zm-axis, or Brush lines around origin.
The “m” in xm, ym, and zm above represents that the coordinates are with respect to the material basis (custom basis).
Additional Color
Select the Additional color check box if you want to blend the appearance with an additional color that is added on the surface using noise. The settings are similar to those for the normal mapping above, but you can also choose the color to add from the Color list and choose a Color blend between 0 and 1. The Noise color is a parameter that affects the appearance of the added color.
Opacity
The default Opacity is 1.
Lighting Model
The default Lighting model — Blinn-Phong or Cook-Torrance — is based on the material. Select Simple instead as needed; it has no additional settings.
The different lighting models provide a set of techniques used to calculate the reflection of light from surfaces to create the appropriate shading. For example, a specular highlight is the bright spot of light that appears on shiny objects when illuminated. Specular highlights are important in 3D computer graphics because they provide a strong visual cue for the shape of an object and its location with respect to light sources in the scene.
For Blinn-Phong, the default Specular exponent is 64. The specular exponent determines the size of the specular highlight. Typical values for this property range from 1 to 500, with normal objects having values in the range 5 to 20. This model is particularly useful for representing shiny materials.
For Cook-Torrance, the default settings are taken from the material. The Cook–Torrance lighting model accounts for wavelength and color shifting and is a general model for rough surfaces. It is targeted at metals and plastics, although it can also represent many other materials, and it includes the following settings.
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The Reflectance at normal incidence value is the amount of incoming light from the normal direction (of the surface) that is reflected.
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The Surface roughness is a value that describes microreflectance on the surface. Higher values create a rougher look of the surface with fewer highlights.
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The Anisotropy is a value that defines the anisotropic specular highlighting. You can use it to give an effect that could be the result of machining or polishing in a certain direction. Select the Flip anisotropy check box to flip that apparent direction. Also, enter the direction of the anisotropy axis as a vector with three components in the Anisotropy axis field.
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The Metallic parameter is a value that affects how metallic the material appears to be. A less metallic material reflects less of the environment. A nonmetallic material cannot reflect the environment
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The Pearl parameter is an artificial effect that mimics the colors of a pearl.
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The Diffuse wrap value gives an artificial effect that you can use to emulate subsurface scattering.
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The Clear coat parameter is an artificial effect that makes surfaces that are parallel to the view direction more white. It also adds specular highlighting and reduces the effect on the environment reflections from the normal mapping.
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The Reflectance value is an additional setting that affects how much of the environment that is reflected.
.You can enter these values in the respective text fields; alternatively, use the sliders underneath each text field to adjust those values between 0 and 1. If you use the sliders, the material appearance is updated directly.