Materials library

Materials library dialog contains information about Radiance material libraries and their contents. In this dialog user can open, explore and save libraries, and also edit and explore separate materials.

It can be opened from toolbar or menu Extensions-> De Luminae-> Global parameters-> Material libraries .

The left part of the dialog contains the material libraries tree. The tree initially contains only entries for libraries distributed with DL-Light extension, but new user-defined libraries can be added.

Material libraries are text files containing definitions of materials in Radiance format. They are of 3 kinds:

• Libraries provided with DL-Light.
• Libraries provided by user,
• Special 'Model materials' library contains all materials attached to tags (layers) in current model. It is dynamically updated.

The original libraries cannot be modified directly, they must be duplicated beforehand to work on the copy. Libraries from the tree can be moved up/down to change their order of appearance. Materials from the tree can be moved (classic Drag-n-Drop) or copied (Drag-nDrop + Ctrl key) to other libraries. Materials from read-only libraries can only be copied to other libraries.

Right part of the dialog contains information about selected entry in the tree. It can be either library or material info.

".cal" calculation files

Some complex materials use an auxiliary calculation file ".cal" (or ".xml", ".pic") in their definition, for example BRTDfunc materials. For all these cases, copy the various subcomponents (".rad" and ".cal") into the folder: "Plugins/DL_common/radiance_extra", "Plugins" being SketchUp's extensions folder. DL-Light will use the contents of this folder to calculate the properties of the materials concerned, as well as the image of the material in the library.

Upon installation, this folder contains two files used by materials from the "spectraldb" library.

Only files with the extension ".cal", ".xml" or ".pic" are copied. (This list can be configured in internal preferences.)

Materials info panel

Top part of panel contains material name, library name and image. Material definition follows.

Material definition can be done on two levels: Basic and Advanced.

• Basic material definition uses the reflectance or transmittance information to generate the material. Material created with 'Basic' features are always grey.
• In basic definition mode, limits to the reflectance ​​and transmittance values are applied:
• Opaque material: 0.0 ≤ Reflectance factor ≤ 1.0
• Transparent material: 0.0 ≤ Transmittance factor ≤ 0.918318
  The limit at 0.918318 corresponds to a transmissivity of 1.0 . To create a "luminous" material of transmissivity > 1.0, use the advanced definition.
• Translucent material: 0.0 ≤ Transmittance factor ≤ 0.908091
• Advanced material definition enables input of material definition in Radiance syntax, and any valid Radiance material can be defined.

If material is updated, its image is automatically created and shown few seconds later.

Control buttons

Library related buttons:

• Create library - create new empty file for materials and add new library entry in the tree.
• Create material - create new material in the current library. New material is by default black, and user should update its info in appropriate controls. This option is not available for read-only libraries.
• Duplicate - create duplicate of the library in a new file. If read-only libraries are duplicated new libraries can be edited.
• Import - import new materials' library into the tree.
• Export - export current library materials to file in Radiance format.
• Reload default - reload default libraries provided with DL-Light.
• Unload library - removes selected library from the tree.

When material is selected in the tree, next buttons are visible in the right part of the window:

• Create material - create new material in the current library.
• Duplicate - duplicate material in the current library.
• Delete material - remove material from the current library.