The Analytic light mimic mesh lights but generate much less noise at lower sampling values than their mesh counterparts (figure 1). The Analytic light parameters can be access from the Shader editor (Figure 2) or the Light Properties Panel (Figure 3).

Figure 1: Analytic light Example


Figure 2: The Analytic light Parameters in the Shader Editor or by the Light Properties panel


Figure 3: The Analytic light Parameters in the Light Properties panel

Parameters

Accessible - Shader Editor and Light Properties

Analytic light Node - Determine the setup of the Analytic light.  

      • Type - Determines the light shape.
      • Spread Angle - Sets the width of the light source's cone of illumination when Quad or Disk light types are selected.
      • Spread Cutoff Hardness - Sets the edge hardness of the cone of illumination when Quad or Disk light types are selected.
      • Normalize Power - Keeps the emitted power constant when the angle changes.
      • Falloff Radius - Determines the falloff distance from the light source.
      • Use in Post Volume - Enables or disables the light in post volume rendering.
      • Emission - The emission type can be either a Texture Emission or a Black Body Emission. See the Mesh Emitters section for more details. 
      • Transform - Contains parameters to move, scale, and rotate the analytic light.
      • Object Layer - Contains the standard object parameters. See the Object Layer Node section for more details.
      • Quad Size - Determines the size of the light source when Quad is selected as the light type.
      • Disc Size - Determines the size of the light source when Disk is selected as the light type.
      • Sphere Radius - Determines the radius of the light source when Sphere is selected as the light type.
      • Tube Cap Radius - Determines the radius of the light source when Tube is selected as the light type.
      • Tube Length - Determines the length of the light source when Tube is selected as the light type.

Texture Emission Node - The default emission when you setup an Octane Area Light. For a list of its parameters, refer to the Texture Emission page.