Planar IES emitter

Description

../../../_images/planar_ies.jpg

Planar spot IES emitter. The emitting geometry is a small rectangle in the ceiling

Emitter The planar IES emitter uses IES data and extracts the half-sphere equivalent radiance for a planar source. It is suited for IES sources which have no or little light emitted in the back direction.

As IES files contain only luminous intensity information and no spectral data, a base spectrum must be specified. It is then normalized to keep the IES values correct.

The actual lumen output will depend on flux mode:

  • In “Per Instance” mode, IES values are mapped to object instances. If a 1000 lumen IES source is applied to two instances of a luminaire geometry, they will emit 1000 lumen each. But if a single geometry models two luminaires, and is instanced once, the luminaires will share the 1000 lumen flux, and will emit 500 lumen each if they are identical.
  • In “Per m2” mode, IES values are mapped to every square meter of geometry. If a 1000 lumen IES source is applied to a 0.20m2 geometry, the resulting light output will be 200 lumen.

Note

Using this feature requires a Lighting or Advanced Edition license

Children Nodes

Spectrum base The base emission spectrum
Text iesdata The IES formatted text data

Parameters

name type description
forward vec3 Orients the IES light source main axis to this direction in tangent space
right vec3 Rotates the IES light source around its axis to set its right pointing at this direction in tangent space. Should be orthogonal to forward
flux list Sets the flux mode (“instance” or “squaremeter”)
multiplier real Multiplies all IES values by this factor

Ocean XML 5.8.3 example

<emitter name="emitter" type="planar_ies" forward="0 -1 0" right="0 0 -1" flux="instance">
     <spectrum type="tabulated" name="base">3e-7 0 4e-7 0 5e-7 1.2e8 6e-7 2.4e8 7e-7 2.9e8</spectrum>
     <text name="iesdata">
             [Truncated IES data...]
     </text>
</emitter>