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Trapcode Lux

Interface Overview

Point Lights

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Point lights in After Effects are points in 3D space that emit light uniformly in all directions. Lux uses three of the prop- erties of the point light to render its representation, they are: position, color and intensity.

In Lux, there are controls for how point lights are rendered. The controls are:

Point Light Model

The Point Light Model controls what type of visualization is used; the look of point lights. There are five settings:

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OffNo visualization of point lights
NaturalLight falls off with distance squared (1/R2). This is the most physically correct model.
RadiusConstant light up to a certain radius. It has the look of a volumetric sphere.
Radius & SourceLike above, but adds a smaller sphere in the center.
SourceOnly the smaller center sphere.

 

Light's Intensity

The Light's Intensity check box controls if the intensity values from the lights should be used. It is on by default, but can be switched off when desired that all point lights look the same regardless of their individual intensity setting.

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Intensity

This slider acts as a master slider for all point lights' intensities. By increasing this value all point lights will be visualized with more intensity by Lux. It however has no effect on the lights' own intensity values, only on how they are rendered by Lux. The top row in the image on the left shows how a light using the Natural Point Light Model is affected. The bottom row shows a light using the Radius model.

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Softness

The Softness slider sets the softness of the visualization. The top row in the image on the left shows how a light using the Natural Point Light Model is affected. The bottom row shows a light using the Radius model.

Radius

The Radius slider only works when Point Light Model is set to Radius or Radius+Source. It controls the size of the spheres.

Individual Radius

The Individual Radius pop-up menu only works when Point Light Model is set to Radius or Radius+Source.

Sometimes it is desired to give the point lights representations individual size. This pop-up gives four choices on how the radius of the individual lights should can be affected:

NoneAll lights have the same radius.
IntensityThe radius is affected (multiplied) by the light's Intensity value.
Shadow DarknessThe radius is affected (multiplied) by the light's Shadow Darkness value.
Shadow DiffusionThe radius is affected (additive) by the light's Shadow Diffusion value.

Example: There are three lights in a scene, the first has inten- sity 100%, the second has 200% and the third 400%. If the Radius control is set to 100 and Individual Radius is set to Intensity then the first point light will have a radius of 100, the second 200 and the third 400.

Source Intensity

The Source Intensity slider only works when Point Light Model is set to Source or Radius+Source. It controls the intensity of the inner spheres.

Source Radius

The Source Radius slider only works when Point Light Model is set to Source or Radius+Source. It controls the size of inner spheres.

Spot Lights

Spot lights in After Effects are points in 3D space that emit light in a certain direction, and with a certain spread (cone angle). Lux uses six of the properties of the point light to ren- der its representation, they are: position, direction, color, cone angle, cone feather and intensity. 

The image on the left shows After Effects properties for a spot light. The setting called Intensity is in this document some- times referred to as the light’s own intensity

spotlights

In Lux, there are controls for how spot lights cones are rendered. The functionality of the controls are described on the following pages.

 

spotlightmodelSpot Light Model

The Spot Light Model controls what type of visualization is used; the look of spot light cones. There are four settings:

OffNo visualization of spot lights.
NaturalLight falls off with distance squared (1/R^2). This is the most physically correct model.
DistanceLight falls off with distance (1/R)
ConstantConstant light intensity. 


Light's Intensity

The Light’s Intensity check box controls if the intensity values from the lights should be used. It is on by default, but can be switched off when desired that all spot light cones have the same intensity, regardless of their own intensity setting.

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Intensity

This slider acts as a master slider for all spot lights’ intensities. By increasing this value all spot lights will be visualized with more intensity by Lux. It however has no effect on the lights’ own intensity values, only on how they are rendered by Lux. The image on the left shows how a light using the Natural Spot Light Model is affected. Notice how the lit area on the layer below (the “floor”) remains unchanged. In order to also affect the lit area, the light’s own intensity value should be changed instead 

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Start Distance

The Start Distance is the distance from the light to where the light cone starts.

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Reach

The Reach slider controls how far the light cone reaches. This setting is only active if the Reach Comp Layer is not checked.

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Individual Reach
The Individual Reach pop-up menu only works if Reach Comp Layer is not checked.

Sometimes it is desired to give the spotlights representations individual reach length. This pop-up gives four choices on how the length of the individual lights should be affected:

NoneAll lights have the same reach.
IntensityThe reach is affected (multiplied) by the light's own Intensity value.
Shadow Darkness

The reach is affected (multiplied) by the light's Shadow Darkness value.

Shadow Diffusion

The reach is affected (additive) by the light's Shadow Diffusion value.

Example: There are three spot lights in a scene, the red has intensity 100%, the blue has 200% and the green 400%. If the Reach control is set to 100 and Individual Reach is set to In- tensity then the red spot light will have a reach of 100, the blue 200 and the green 400. 

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Reach Comp Layer

When Reach Comp Layer is activated, a 3D layer can be selected in the layer pop-up below. The spotlight cones will then reach that layer.

 

Set Reach Layer

When a layer is selected in this pop-up menu, all spotlight cones will be set up to reach that particular layer. As soon as the layer has been selected, the pop-up will flip back to its original state, None, and a new light called “Lux Reach [layer-name]” will be created. This is a locked light, you are not supposed to edit it, it’s just there to keep track of the reach layer. 

The layer selected here must be a 3D layer, otherwise it will have no effect. This control only works when Reach Comp Layer above is checked. 

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Reach Both Sides

All layers have two sides. Normally Lux doesn’t care which side faces the light, it will still get stopped by the reach-layer anyway. But if this option is unchecked, then only one side of the layer will be able to stop (cut off) the light cone, the other side will do the inverse - start the light cone. The image on the left shows what happens when Reach Both Sides is off and the reach-layer is rotated so that the other side faces the light. 

General

The settings in the general group affects both point and spot lights.

Use Lights that are

The setting allows for using only lights that are switched on, or only lights that are off, or to use all lights regardless of if they are switched on or off. 

Name starts with

Using this option, Lux will only visualize the lights that have names that start with a certain word. This gives flexibility to add many lights to light the scene, but only let a few of those be rendered by Lux. It also helps when it is desired to have lights behind and in front of some layers. In this case two instances of Lux are used. One is placed on top of the layer stack and another at the bottom, then this pop-up can be used to control which lights are rendered in what Lux layer. 

Anything All lights are rendered
LuxOnly lights whose names start with "Lux" are rendered.
FrontOnly lights whose names starts with "Front"
BackOnly lights whose names start with "Back"

Important note: Changing the name of a light does not force After Effects to re-render. This must be done manually by for example purging the image cache or switching the Lux layer off and then back on. 

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Look

This setting controls how lights are mixed together and the overall brightness and the look of the result. There are six modes for Look:

WeakAn overall weak look.
LinearA normal look with bright areas in the overlaps between lights.
NaturalA normal look with natural looking overlaps between lights.
StrongAn overall bright look.
Adjustable LinearAn adjustable look with bright areas in the overlaps between lights.
Adjustable NaturalAn adjustable look with natural looking overlaps between lights.

Gamma

The two last Look modes (the adjustable modes) enables this gamma slider that allows for adjusting the overall brightness and look.