Radiance Data Files

The following data files may be found in the “Radiance” sub-directory:

 

Contains information which affects the sky conditions -date, time, site and sky. This file contains a call to the Radiance program gensky, which takes the date and time as parameters (“9 21 10.00”) and also site data (“-a 51.50”). There are 7 standard sky conditions available:

+s – sunny sky

-s – standard clear sky

-c – standard CIE overcast sky

+I – intermediate sky with sun

-I – intermediate sky without sun

-u – uniform cloudy sky

10K_cie – CIE overcast sky fixed to 10K Lux

 

Contains data on the patterns and materials that are assigned to the constructions in the model.

This file contains a geometrical description in a form that Radiance can interpret. If luminaires and/or components are also to be included in the simulation additional data files containing this information are created. In the current setup a parent file which references all these files is created.

This file contains the parameters for a particular view - the type of view (perspective/plan), the eye position (x, y, z), the viewing direction, angles of view, etc.

This file is created when the user saves the contents of the “Eye view position” dialog items. When the user creates images interactively without specifically saving the view parameters a file with the same root name as the project is created. This file is defined as a parameter to the rpict module, which generates the radiance image.

This file contains the simulation parameters that determine how accurate the simulation will be - ambient bounces, etc. This file is created when the user saves the contents of the “Accuracy” dialog items. When the user creates images interactively without specifically saving the simulation parameters a file with the same root name as the project is created. This file is defined as a parameter to the rpict module, which generates the radiance image.

A binary data file created by oconv and read by rpict, contains the octree data structure, which is used to speed up the ray-tracing algorithm. If the resultant image is a luminance image the octree file is used in the calculation of glare. For illuminance images the octree file can be discarded when the image has been created.

An octree is a data structure that subdivides a cubic volume of space into eight sub-cubes, each of which may be subdivided into eight sub-cubes, and so on recursively. This data structure is created by the program oconv and is used to speed up ray intersection tests on the scene. This data structure is stored in the octree file.

This is an intermediate picture file created by rpict and filtered and scaled by pfilt to generate the final image. It is deleted by the batch job after the filtering process and is only found if the batch process is interrupted. It has the format and structure of a picture file.

The file is created at four times (2 by 2) the picture size as defined in the “Eye view position” tab. The eventual size depends on the aspect ratio derived from the horizontal and vertical viewing angles (or width and height for a plan view).

 

The final simulated picture, a binary file written in a customized format. Created by pfilt from the raw file as the final step of the batch process, which creates the finished image. Depending on the simulation parameters can be either an illuminance or luminance image.

Luminance images are used to generate glare and illuminance images are used to generate Lux values and Lux contours (and DF contours).

The first image to be created has the root project name (e.g. model.pic) and subsequent images have a number appended to the root name (i.e. model1.pic, model2.pic, etc.). If images are deleted then the number sequencing may be out order, it is left to the user to rename the images if required. Note that the image list in the “View images” tab sequences the images in the order they were created. Contour images have the labels “_LC” or “_DF” appended to the name, or if more than one contour image is created then additional numbers will be added e.g. “_LC1”, etc.

 

The file “Radiance.log” keeps track of the progress of the processes involved in generating an image (this file is used to update the progress bar). Any warnings and errors are also written to this file. The file is written in append mode and it is left to the user to delete it as required.

This file is used to piece together the various files used to generate a simulation (see diagram on page 2). There are two contexts in which this occurs - when the user interactively creates an image from the “Create image” tab, and when the user assembles batch processes from the “Files/Queues” tab. In the “Create image” tab this process is concealed from the user and the files used are given default names (using the root project name), which are automatically updated from the current settings.

This file conforms to the standard description of a luminaire as defined by the Illuminating Engineering Society of North America. It combines the data for the candlepower distribution of the luminaire with miscellaneous other data items e.g. luminaire dimensions. This file is written out by LightPro.

The *.ies file is converted by the program ies2rad into a format usable by Radiance (the *.rad file and the *.dat file).