3D Lights Lecture Outline

“3D Lights”

 

  1. Lights!
    1. Are represented as layers in compositions
      screenshot-2016-11-01-12-36-57
    2. Simplified approximations of real-world lights
    3. Each light layer has its own various timeline properties, for example:
      1. Intensity controls a light’s brightness
      2. Color behaves like a colored gel sheet or filter over the light
      3. Cone Angle (for spot lights only)
    4. Comps can have more than one light, and more than one light often looks best (there are tons of exceptions of course)
    5. But: too many lights can make previews and renders become sluggish, and this can bog down your creative process. (Same goes for 3D layers. Try to find ways to simplify or “cheat”)
    6. Lights can be parented to other layers, and vice versalayers can be parented to lights.
    7. Lights themselves are invisible in the render (including with their light beams) but you can sometimes fake a light cone using semi-transparent Shape layers or masked Solid layers, and there are also 3rd-party plugins for sale which can make the lights/beams more visible; e.g., Trapcode Lux.
  2.  Layers Affected by Lights
    1. Lights can only cast their wonder on 3D layers; 2D layers basically ignore lights
    2. Lights affect ALL 3D layers by default.
    3. But, each 3D layer has a property called Accepts Lights which can toggle whether it should be affected by lights or not
      screenshot-2016-11-01-11-51-25
      3D layers with Accepts Lights turned off will appear at full brightness, useful for simulating video screens, the sky, stars, fire, or anything else that would emit its own light in the real world
    4. All lights can be temporarily disabled using the Draft 3D switch (set to on)
      screenshot-2016-11-01-11-56-50
      This is useful for speeding up previews while working, and for seeing layers that might otherwise be too dark to see. (This switch also temporarily disables any camera layer’s Depth of Field property.)
  3. The Four Types of Lights: Parallel, Spot, Point, Ambient
    1. Point lights behave like spheres of light
    2. Spot lights behave like cones of light. The light’s point-of-interest (similar to how a camera’s point-of-interest works) is used to control the direction of the cone.
      1. Cone Angle
      2. Cone Feather
    3. Parallel lights behave like sunlight or moonlight: for when the imaginary light source is far away and light beams hit everything at the same angle. Light (x,y,z) source position is somewhat irrelevant, as point-of-interest matters most.
    4. Ambient lights are immersive and light all surfaces equally. Useful for bringing up/down the overall brightness of a 3D scene. Shadows not possible with this light.
  4. Falloff – In the real world, as lights get farther away, they get less bright. This is called “Falloff”. In After Effects, there are 3 types of Falloff:
    1. None – Lights from far away shine equally bright as close up lights. Light brightness on a surface is determined by the angle that the light rays hit the surface.
    2. Inverse Square Clamped falloff
      1. Most like real-world lights
      2. Radius option adjusts how quickly this falloff is applied
    3. Smooth falloff
      1. Similar to Inverse Square Clamped but with more control over when falloff begins to happen. Useful when your 3D layers are not exactly positioned the way they would be in the real world.
      2. In addition to Radius, there is a Falloff Distance option
      3. When working with these lights, try setting the Falloff Distance to 0 while adjusting the Radius value, then increase the Falloff Distance
  5. Lights (and 3D Layers) Can Create Shadows
    1. Lights have a Casts Shadows property which can be turned On to create shadows in the comp
    2. Each 3D layer also has a Casts Shadows property which you toggle to On in order to make the layer cast shadows. 3D layers do not cast shadows by default.
    3. A 3D layer’s Casts Shadows property can also be set to Only which makes the 3D layer invisible but still able to cast a shadow. Useful for special circumstances where a shadow requires more custom placement, sizing, rotation, etc.
    4. Shadow appearance is controlled via an individual light’s settings:
      1. Shadow Darkness a percentage value typically from 0% to 100%, but can go higher than 100%
      2. Shadow Diffusion a pixel value indicating a shadow edge feathering amount