This group maintains a database and publishes this data via a program called Optics 5. From Optics 5 you can then export a Radiance Material (*.rad file), which can be interpreted
as mental ray A&D Material parameters.

To convert Optics 5 data into A&D Material suitable for lighting analysis, export a glazing or glass definition as Radiance (*.rad) from Optics 5. You will find this command under File | Export to Radiance File.

Once the file is exported on disk, open it in Notepad and search for a section that looks like this:

void BRTDfunc B530_front
10
0.245 0.281 0.340
0.169 0.197 0.187
0 0 0

The color coefficients (RGB) for the ideal specular reflection corresponds to 0.245 0.281 0.340. The color coefficients for the ideal specular transmission corresponds to 0.169 0.197 0.187. Those values will need to be used as a basis for the mental ray A&D Material.

How to use the provided Microsoft Excel spreadsheet to convert to the mr A&D Material.

To correctly convert specular reflection and transmission from a Radiance material to a mr A&D Material, we need to take into account internal energy conservation methods that are built in the mr A&D Material that are not factored by the Radiance material. In other words, numbers can’t be “plugged-in” as is.

To help you with this task, we developed a Microsoft® Excel® software spreadsheet that will let you do this precisely. The spreadsheet can be downloaded here.

Limitations:

• The Radiance Materials exported from the Optics 5 database does not take into account angular dependency: A Fresnel falloff curve is assumed so metallic-coated glazing systems may be less precisely simulated.
• The Optics 5 database contains optical data measured spectrally. The exported Radiance materials and the A&D materials use RGB colors which are a crude approximation of the visible light spectrum. Therefore, lighting simulations are done within limitations of RGB colors.

The measured color palettes can be exported from the Color Munki software as *.CxF files and read back in 3ds Max with the help of a script that I have developped.

The 3ds Max script can be downloaded here.  Simply run it from within 3ds Max using the Maxscript | Run command, browse to a CxF file and drag and drop colors in your materials from the color swatch of your choice.

The first one will be on the topic of Daylight Simulation  with 3ds Max Design 2010. The second one will be about strategies to estimate optical characteristics of surface finishes for accurate renderings.

Daylight and Lighting Analysis with Autodesk® 3ds Max® 2010:

• How to predict lighting levels in a scene lit with daylight or electric light
• Finding correct values of reflectance and transmittance for the building materials you create and using these values in a lighting render of an existing building
• Importing and using the correct photometric information for a particular manufacturer’s light fitting
• Creating animated daylight simulation studies and experiencing your building in a dynamic way
• Limitations of lighting analysis programs
• Using MAXScript to perform advanced lighting analysis tasks

Capture and Acquire Appearances of Real World Materials for Improved Accuracy in Renderings:

• Rendering engines and color
• Gamma Correction and Linear Workflow
• Color acquisition devices comparison
• Measuring optical characteristics of materials in an affordable way
• Using this data correctly in Physically Based rendering engines

 
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