RadianceIES

A detailed 3D simulation tool designed to predict daylight, and the appearance of internal spaces prior to construction.

RadianceIES is the software tool that sits at the heart of any simulation that considers the daylight or artificial lighting design of a building. Fully adherent with all international standards Through good daylighting design RadianceIES helps designers worldwide effectively decarbonise their buildings. Validated and accredited for use and when used alongside ApacheSim in all IESVE’s code compliance and voluntary rating system offerings RadianceIES drives the global push to Net Zero.

  • Design the optimal lighting system for your building and the people who use it, taking into account quality of both natural and artificial light.
  • Visualise how brightness and glare influences a building occupants visual comfort.
  • Investigate daylight dimming opportunities and quantify energy reductions by linking to ApacheSim.
  • Undertake Right-to-light studies and test how different lighting schemes will look and perform.
  • Utilise our Climate Based Daylight Modelling (CBDM) technology to model space performance.
  • Produce photo-realistic rendering images based on detailed physically accurate lighting simulations.
  • Ability to run multiple calculations and dynamic simulations simultaneously using the Parallel Simulation Manager.
  • Queue any number of simulations and run at pre-defined times for increased efficiency (e.g. outside office hours)

Simulations can include detailed complex geometry and a wide variety of material types. Both luminance (what your eye sees) and surface or working plane illuminance (what the surface receives) can be analysed. An extensive array of lighting analysis techniques that align with international codes and standards can be assessed with RadianceIES including the following: 

  • Lux Levels (Illuminance)
    • Rendered image or tabular text
    • Figures displayed at any point on the image – grid
    • At a defined working plane height
    • Contour line, contour band and false colour images
    • Jpg & bmp file format export
  • Daylight factors (Illuminance)
    • Rendered image or tabular text
    • Figures displayed at any point on the image – grid
    • At a defined working plane height
    • Contour line, contour band and false colour images
    • Jpg & bmp file format export
  • Glare (Luminance)
    • Rendered images with glare indices overlay
    • Table showing Guth Index, CIE Index, Unified Glare Index
    • Daylight glare probability index
    • Jpg & bmp file format export
  • Climate Based Daylighting Metrics
    • Useful Daylight Illuminance (UDI)
    • Spatial Daylight Autonomy (sDA)
    • Annual Sunlight Exposure (ASE)
    • Coloured analysis bands and contours can be shown on 3D ModelViewer


This application uses sophisticated ray-tracing techniques to produce a physically accurate representation of light distribution. It can take into account:

  • Date & time
  • Sky conditions (from selection of internationally recognised conditions)
  • Working plane (if required)
  • Eye & focus positions (apply graphically or numerically)
  • Glare threshold
  • Inclusion / exclusion shading surfaces: adjacent buildings, topographical shades, local shades
  • Option to choose sky resolution to speed up calculation of daylight coefficients  
  • Surface Properties 
    • Integrated to project construction database 
    • Colour – including components and shading surfaces
    • Optical material properties from a pre-defined list
    • Surface patterns of varying textures
    • Can be defined by imported images
    • Bidirectional Scattering Distribution Function (BSDF) – to capture detailed light distribution
  • Components – internal or external fixtures and fittings, furniture etc – to add more realism to the simulations 
    • Add from the global components library and amend if required
    • Create or import your own
  • Image Properties- or how you want to view the results as images can be defined
    • Field of view
    • Size
    • Quality
  • Luminaires (if using in conjunction with LightPro)
    • Assess artificial light levels during the day or night
    • Assess light pollution, or light distribution in the external environment
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RadianceIES Screenshot
RadianceIES Screenshot
RadianceIES Screenshot
RadianceIES Screenshot
RadianceIES Screenshot
RadianceIES Screenshot
RadianceIES Screenshot
RadianceIES Screenshot
RadianceIES Screenshot
RadianceIES Screenshot