formZ | Lighting | Lights - Emitter Type

Owned by Systems Next Limit (Unlicensed)
Last updated: 29 Nov, 2023 by Next Limit
6 min read

Lights

The plugin provides a suite of abstract light types to quickly set up sophisticated interior lighting. These are accessed through formZ's Lights palette and Light Parameters dialog.

The native light types Point and Cone are supported by Maxwell. Additionally, the plugin adds several new light types:  Softbox, Ambient Field, IES, and Projector

When the scene is exported, each light is automatically converted into emitter-mapped geometry suitable for Maxwell.

Common Parameters for all Emitter Light Types

Parameters common to most types follow:

Intensity Tab

 

  • Color: Selecting RGB will assign the color picker color to the emitter output. Alternately, select Temperature to specify the emitter output in degrees kelvin.

  • Luminance: The luminance of the source can be specified via a number of industry-standard schemes, such as input power and efficacy, lumens, lux, etc.

 

Shadows Tab

Maxwell emitters always cast shadows, so this option is disabled when editing a Maxwell light type.


 

Point

Point lights are converted into emitting spheres

formZ’s Point lights are supported by the plugin. Point lights have the following unique parameters:

Parameters Tab

  • Multilight Group: When editing in Multilight, all lights and emitter materials with this named tag will be available under a single slider.

  • Enabled: When enabled, the light will be exported to the Maxwell scene.

  • Hide from camera: Enabling this option makes the lamp geometry invisible to the camera, but still allows it to contribute to the lighting calculation (it will cast shadows, refract etc).

  • Hide from Reflections / Refractions: When enabled, the lamp geometry will not be reflected or refracted in other objects.

  • Hide from Global Illumination: When enabled, the lamp geometry will be visible, but it will not cast shadows or reflect light back onto other objects.

  • Quality: [1-Lowest - 5 Highest] Controls the number of faces (polygons) making up the emitter object. The default value (2) should work in almost all cases. Increasing this value may eliminate lighting artifacts, but will also increase render time.

  • Diameter: Sets the diameter of the emitter sphere (bulb). Geodesic spheres are used for an even of distribution and maximum efficiency.



Cone (Spotlight)

Cone widget: Falloff region lies within the inner and outer circles

formZ’s Cone lights are supported by the plugin. Cone lights have the following unique parameters:

Parameters Tab

  • Multilight Group: When editing in Multilight, all lights and emitter materials with this named tag will be available under a single slider.

  • Enabled: When enabled, the light will be exported to the Maxwell scene.

  • Falloff: Linear, Square Root, Sinusoidal, Squared Sinusoidal, Quadratic, or Cubic falloff within the penumbra.

  • Blur: De-focuses the light. Values greater than 100% are permissible.

There is a global override flag to enable/disable the export of all cone and point lights in the scene. See Render Options: Scene.



Softbox

Softbox widget shows emitter dimensions and direction

The Softbox type is patterned after the photographic instrument of the same name, where a bulb illuminates the subject though a rectangular diffusion screen to create a localized, yet "soft," light. The plugin creates a rectangular plane mapped with an emitter material.

When the Softbox light body is moved, it will always will always remain level with the ground plane and point toward the light's center or interest.

Parameters Tab

  • Multilight Group: When editing in Multilight, all lights and emitter materials with this named tag will be available under a single slider.

  • Hide from camera: Enabling this option makes the lamp geometry invisible to the camera, but still allows it to contribute to the lighting calculation (it will cast shadows, refract etc).

  • Hide from Reflections / Refractions: When enabled, the lamp geometry will not be reflected or refracted in other objects.

  • Hide from Global Illumination: When enabled, the lamp geometry will be visible, but it will not cast shadows or reflect light back onto other objects.

  • Width, Height: The width and height of the Softbox. The width is always level with the ground plane.





Ambient Field

Ambient Field widget shows field extents

The Ambient Field light was designed to flood architectural interiors with a soft, diffused light. This light type works by filling a cubic volume with a "cloud" of randomly oriented, light-emitting triangles.

The light's Origin and COI handles can be adjusted to define the minimum and maximum points of the world-aligned cubic volume. This light is not directional.

Parameters Tab

  • Multilight Group: When editing in Multilight, all lights and emitter materials with this named tag will be available under a single slider.

  • Quality: (1-100%) Controls the number of light-emitting triangles created at render time. In most cases a setting of between 1 and 10 is sufficient. If light on neighboring surfaces looks uneven ("blotchy"), increase this parameter. Higher values require longer to render.

 

IES

Relative intensity distribution pattern indicators for three IES lights

IES and EULUMDAT files specify the intensity and direction of emission from specific light fixtures. These files are available from manufacturers.

The base of the fixture, as defined by the IES / EULUMDAT file (i.e., the negative-Z axis), will always point toward the light’s COI.

Intensity Tab

  • Open: Select the IES or LDT file. A 2D sectional representation of the distribution pattern is displayed below the filepath field.

  • Delete: Remove link to the file.

  • Intensity: Override the intensity of the light as defined in the IES file.



Parameters Tab

  • Multilight Group: When editing in Multilight, all lights and emitter materials with this named tag will be available under a single slider.

  • Spin: Controls the rotation of the fixture about the axis defined by the light origin and COI. The origin of rotation (0 degrees) always points ‘down’ to the ground plane (XY plane).

  • Length: Controls the length of the IES distribution pattern widget in the 3D modeling space.

 

 

Projector

Projector light



Projector lights can be used to simulate light beams, video projectors, and the like. Please see the Maxwell documentation about Spot emitters for more details on these parameters.

Intensity Tab

  • Open: Select the image file to be projected. Both standard and HDRI formats are supported.

  • Delete: Remove link to the file.

  • Intensity: Light intensity.

Parameters Tab

  • Multilight Group: When editing in Multilight, all lights and emitter materials with this named tag will be available under a single slider.

  • Angle: Field-of-view of the projection

  • Spin: Controls the rotation of the fixture about the axis defined by the light origin and COI. Zero degrees results in the image appearing "upright" relative to an observer on the ground plane.

  • Blur: De-focus the image. Values greater than 100% are permissible, and may be necessary to achieve sufficient blur when the projector and projection surface are at a great distance.