SketchUp - Materials

Materials in the plugin exist as a set of parameters which are attached to each individual SketchUp material contained in the document. When a material is selected, either by selecting a SketchUp material in the SketchUp materials browser, or by selecting a material from the drop-down at the top of the Materials page, these parameters are made available for editing in the plugin's material editor user interface. The material editor interface has two main sub-panels, one which holds the material preview and any notes stored with the material, and a second, which is used to set various physical parameters of the material.

Toolbar

The Materials panel's toolbar contains the following items:

Undo/Redo

These two drop-down lists hold the history of actions which have been executed in the material panel. They are cleared when a new document is opened, or when a different material is selected.

Entity/Material Selection Tool

This button toggles the activation state of the plugin's Select Tool.

Assign to Selected Entities

This button is provided as a convenience; clicking it simply assigns the current material to the current SketchUp selection.

Material List

This drop-down provides a list of the materials contained in the SketchUp document. Materials may be selected here, or by selecting them in SketchUp.

MXM Mode

This (toggle) button switches the selected material between its Embedded and MXM modes.

Preview

At the top of the material editor, you will find a material preview image, a place to store notes about the material, a drop-down to select the preview scene used by this material, and a slider used to set the target SL (Sampling Level) used whenever this material's preview is rendered.

The plugin uses Maxwell Fire to provide real-time material editing. To render or re-render the preview for the current material, click the Render Preview (small arrows) button, located near the lower right corner of the preview image; if the preview is already rendering, clicking this button will cause it to stop. While a preview is rendering, its current sampling level will be shown in the lower left corner of the image.

Material previews can be rendered manually this way, or they may be generated in real-time via Maxwell Fire, updating automatically whenever a material parameter is changed. This behavior is controlled by the Refresh Previews plugin option. In either case, the rendering may be started or stopped by clicking the Render Preview button. Note that the size of the preview image is adjustable; to change it, just pass your mouse over the lower right corner of the image to show the resizing grip. Smaller previews will, of course, take less time to render.

Also note that it is possible to set the number of processing threads which are used for rendering previews using the Preview Threads plugin option.

Notes

This is a text field that is stored with the material.

Scene

In this drop-down, you will find a list of MXS files which have been found in the preview sub-directory of your Maxwell installation directory. The chosen MXS preview scene will be used to render previews for this material. This setting is stored per-material, enabling each material to use the preview scene most appropriate to its nature.

Size

This parameter, which is stored on a per-material basis, simply sets the size for the preview image.

Quality

When the material preview is rendered, it will render until the Target SL set here has been reached. This value is also stored on a per-material basis, since some materials require lower SLs than others.

Character

The factor primarily responsible for determining the appearance of a Maxwell material created with the plugin is known as its Character.

Character determines whether the material is glass, metal, etc. Character is primarily concerned with the nature of the material on a conceptual level, and not with anything specifically having to do with the material's color or texture; those things are independent from its character. In total, there are fifteen character types:

Type	Description

Type	Description
Automatic	This is a material's default type. It provides a Roughness parameter; as Roughness is decreased, the material will shift from a pure diffuse to a smooth plasticine material.
Opaque Transparent Translucent AGS Metal Car Paint	These are based on the Maxwell Material Assistants. For more information on their parameters, please see here.
Plastic	This type describes a hard plastic. It provides Roughness and Nd parameters. As Roughness is decreased, the plastic will become smoother. The Nd value controls the reflective response of the material; lower Nd values result in weaker frontal reflectivity.
Lacquer	This type is designed to create a material which resembles a lacquered surface, and is generally intended to be used in conjunction with a woodgrain texture. It provides a Finish type, of which there are five: Rubbed, Satin, Semigloss, Gloss, and Polished.
Liquid	This type simply produces a liquid material. It provides an Nd parameter, which is set to the refractive index of water (1.33) by default. Being a true dielectric material, this type should only be used on objects which have a closed volume.
Glass	This type is similar to the Liquid character, but it adds a Roughness parameter. Its Nd is set to the refractive index of standard glass (1.51) by default. As with Liquid materials, Glass materials should only be used on objects which have a closed volume.
SSS	This (SSS stands for Sub-Surface Scattering) type produces a material which possesses complex internal scattering effects (as this is a dielectric material, it should only be used with objects which have a closed volume). This type provides Roughness, Thickness, Density, and Asymmetry parameters. Thickness is used to scale the material based on the basic size of object on which it will be used; lower values will cause light rays to terminate closer to the surface of the object. Density describes how many particles per volume the material contains; this affects how light is scattered inside of the volume with more dense materials looking more opaque and less translucent. Asymmetry determines the back- or forward-scattering characteristics of the material; positive values cause light to bounce back toward its source, and vice versa for negative values.
SSS (Single Sided)	Single Sided SSS (or SSSSS, for purposes of this discussion) is a special Sub-Surface Scattering mode designed for use with single-face meshes; regular SSS is unsuitable for use with such geometry, due to its dielectric nature and the resultant requirement that it be used with an object which describes a closed volume. The SSSSS character provides Roughness, Thickness, and Asymmetry parameters. Thickness determines the theoretical thickness that Maxwell will give to single-face meshes such materials are applied to. Asymmetry, as with regular SSS materials, determines the back- or forward-scattering characteristics of the material.
Satin	This type has no parameters, and produces a material which behaves like satin cloth.
Velvet	This type has no parameters and produces a material which behaves like velvet cloth.
Complex IOR	This type has no properties other than Roughness; rather, its rendering characteristics depend on the selected Complex IOR file. See the IOR files page in the regular Maxwell Render documentation for information.
Emitter	This type produces an emitter material using the supplied Watts, Efficacy, Temperature and Roughness parameters. The amount of light the emitter material will output is determined by two parameters: Watts, which specifies how much electricity this emitter would consume, and Efficacy, which determines how efficiently the emitter converts that electricity into lumens (a unit of measure for light output). This allows you to set your emitters using real world values, often found on light manufactures websites. Temperature is optional: when disabled, the normal RGB color of the material will be used. As Roughness is reduced, a glass-type BSDF is mixed into the material, such that at a Roughness of 0.0 (and if the emitter is weak enough to reveal the glass-type BSDF), the material will resemble a light bulb. For more information on using emitter materials, see here.
IES Emitter	This type produces an emitter whose light source is an IES or LDT file. Intensity and Temperature parameters are provided, with Intensity adjusting the power output of the emitter. As with the standard Emitter Character, Temperature is optional, with the normal RGB color of the material being used when it is disabled. This type has no Roughness parameter, since IES/LDT emitter materials are intended to be used on geometry which has been hidden to the Maxwell camera. For more information on using IES emitters, see here.
HDR Emitter	This type produces an emitter whose light source is an HDR, MXI, or EXR file. Intensity and Roughness parameters are provided, with Intensity adjusting the power output of the emitter. Similar to the regular Emitter character, as Roughness decreases, a glass-type BSDF is mixed into the material, allowing materials like an LCD screen to be simulated. For more information on using HDR emitters, see here.
Image Projector	This type is somewhat similar to an IES Emitter, except that its light source is an image file, which is projected outward from the geometry to which it is applied. It is best to use a sphere (group) for this purpose; the focus of the projection will be dependent upon the diameter of the sphere. For more information, see here.
Spotlight	Applied to a group (in order to achieve directionality), this type produces a virtual spotlight.

Directional light material types (IES, Image Projector, Spotlight, or linked MXMs using these types) should be applied to groups, not individual faces, since the lighting produced needs to have a direction.

Color

Where the Character determines the physical properties of the material, its Color determines its basic color.

Mode

The material color can either be linked to the color of its associated SketchUp material, or it can be set independently. If the color mode is set to Link to Application, then any changes made to the color here will be sent to SketchUp, while any changes made via SketchUp's own material editor will be reflected here. If the color mode is set to Use Specific Color, then this link will be broken, and the color of the associated SketchUp material will be disregarded.

Of course, when the color is not linked, what is seen in SketchUp's viewport may not match what is seen in the rendered Maxwell image.

Color Picker

Colors may be entered manually, using either the sliders or numeric inputs, or by click-drag on the color-picking surfaces. There are drop-down lists containing named and numbered preset colors, and there is also a list of custom colors available. At any time, the current color may be added to your list of custom colors; you will be prompted to provide a name for the color.

Texture

Similar to the Color parameter, a material's Texture determines its basic color, when a texture is present (if there is no texture, then the material's Color will be used).

Source

Just as a material's Color may be linked to its associated SketchUp material's color, its Texture may also be linked to the SketchUp material's texture. When Source is set to Use Specific Texture, this link will be broken, allowing you to choose a different texture map. When Use Specific Texture is activated, there is also a checkbox provided, by which the texture may be temporarily disabled.

Texture Editor

The texture editor provides controls by which you may adjust projection and image values. You may also Invert the RGB values and instruct Maxwell to apply interpolation to the texture's pixels at render-time using the Interp. (i.e. interpolation) switch. Please note that only images able to be shown in your browser are able to be previewed here.

Bump

Where the Color and Texture parameters control the basic color of the material, the Bump parameter controls bump-mapping effects.

Strength

Bump values in Maxwell range from -100% to 100%; setting a value of -50% is the same as inverting the texture and using a bump value of 50%. When the bump mode is set to Displacement, then this parameter specifies the displacement height in millimeters.

Mode

The Bump texture may use one of the following modes: Bump Mapping, Normal Mapping, Displacement. Normal mapping should be selected when the specified map is a normal map. If Displacement is used, then the map should be a black and white map, preferably 16-bit or better. As mentioned previously, when Displacement mode is used, the Strength parameter specifies the displacement height in millimeters, rather than in percent, as is the case for the Bump and Normal mapping modes.

Source

Similar to the way that a material’s Color texture may be linked to the associated SketchUp material’s texture, the material’s Bump texture may be linked to its Color texture. If it is desired that a specific bump map be used, switch Source to Use Specific Texture and browse to the desired texture file.

MXM Mode

What has been discussed up to this point is known as the Embedded material mode. Embedded refers to the fact that the parameters which will define the material in Maxwell are stored directly in the SketchUp document, and are edited, as has been explained above, entirely from within the plugin's user-interface. Optionally, it is possible to switch a material into its MXM mode; in this mode, the built-in parameters will not be used, and the material will reference an MXM file instead. To switch to MXM mode, click the MXM toggle-button at the top-right corner of the Materials page:

When MXM mode is activated, the page will 'spin' around to reveal a different interface:

Here, an MXM file has been loaded from the local disk. The preview image for the MXM file has been shown, and the Copy Color to SketchUp Material button, found near the top-right, has been clicked; the color chip next to the material's name in the material list has been updated (it was previously blue), as a result of the material's color having been changed in SketchUp.

There are five buttons in the MXM mode interface:

Browse

Click this button to choose an MXM file.

Edit

This button opens the MXM file in Maxwell MXED for editing. When MXED is closed again, the plugin will check to see whether the file has been updated or not; if it has, the MXM preview image will be updated to reflect the new state of the MXM file.

Clear

This simply clears any current MXM file.

MXM Information

Clicking this button shows a listing of details about the currently-selected MXM file:

Copy Color to SketchUp

When an MXM file is present, this button will be visible. Clicking it will copy the basic color of the MXM file into this material's associated SketchUp material.

Copy Texture to SketchUp

Similar to the previous item, this button will copy the MXM file's selected texture into the associated SketchUp material's texture. This button will only be shown if the MXM file has a selected texture, and if that texture is able to be found in the file system. An MXM file's selected texture is set using the drop-down list of textures next to MXED's Refresh Preview button.

Notes on the use of MXM files

The Maxwell MXM specification includes the concept of real scale textures (this is the case when you set an MXM texture's Method to Meters), in which it is assumed that the plugin used will ensure that the UV coordinates exported for objects are sized in such a way as to ensure that a texture Tile value of 1.0 will correspond in the rendering to 1 meter.

This can be quite useful in some cases, but in the case of SketchUp, it is both unnecessary and incompatible with the way that SketchUp works. This is because SketchUp:

has no concept of a texture repeat value.
always creates texture UVs in terms of real-world scale sizes.

For these reasons, it is best to use MXM files which simply specify 1.0/1.0 in their texture Repeat values, and which do not use the Meters method. If MXM files used from the plugin have values other than these, the result will be that the texture mappings seen in SketchUp's viewport will not match those in the rendered image.