ProVideo Coalition.com: Creating Motion Graphics: Keyframes by Chris & Trish Meyer

Part of the subtle power of lighting in After Effects is that illumination can go beyond 100%. You can increase a light’s Intensity beyond 100%, and also adjust a layer’s Diffuse and Specular Material Options to add up to more than 100%.

If the angle between the light, layer, and camera is not perfect, the result is less than 100% of the available light being bounced back to the camera, and the layer appearing darker than normal when using the default settings for lights and layers. To cure this, just increase a light’s Intensity until the layers are bright enough again.

The real fun comes in creative uses of “blowing out” portions of a layer by cranking up the overall illumination; an example is shown at right. Increasing the Diffuse and Specular values to add up to greater than 100% result in interesting color shifts in the hot spots, as their individual color channels increase in value and clip at 100%. Radically increasing a light’s Intensity results in highly stylized versions of the original imagery. The results are similar to use the Add transfer mode to combine layers.

Metal and Plastic

Two additional Material Options have an effect on how specular highlights are calculated: Shininess and Metal.

Shiny objects have smaller, tightly-focused highlights. The default Shininess value is a very broad (and unexciting) 5%, making the Specular lighting effect of a layer look almost identical to the Diffuse lighting effect. To get a more classic highlight, set Shininess to 50% or higher. Ironically, this will make a layer appear darker, as the additive specular effect will not be spread so broadly across a layer. Therefore, it’s a good strategy to set the Diffuse value close to 100%, and then adjust the Specular value depending on how blown out you want the highlight to be.

Metal objects tend to have highlights that are similar in color as their surfaces. Plastic objects tend to have highlights that are closer to the color of the light hitting them, looking more like glare. The metal look is often sexier.

In After Effects, a layer’s Metal Material Option defaults to 100%, which means the highlights are similar in color to the layer itself. However, if the layer has a dark color to start, and the specular highlight is the same color as the surface, it’s very hard to brighten this layer with lights. An extreme example of this is black text. To add a harsh glare, or to see a light’s color more strongly on a layer, reduce the layer’s Metal value.

When a layer’s Metal parameter is set to 100% (the default), specular highlights have a similar color as the underlying layer – which can be a problem is the layer is predominately black (upper left). Decreasing the Metal value increases the influence of the light’s color, resulting in a “glare” effect (above). This also heightens the effect of colored lights on dark surfaces (left). Image from EyeWire/Getty Images – Discovery.

Master Materials

The Material Options are so important, it would nice if there was an easy way to copy all of them from one layer to another – but there isn’t. To copy individual parameters, reveal the Material Options in the Timeline window, select the property you want by clicking on its name (not its value), and copy. Remember you can Shift+click to select a contiguous set of properties, or Command+Shift on Mac (Control+Shift on Windows) to select specific properties that are not adjacent to each other. Then select the layer you wish to receive these values, and paste.

Another approach is to use Expressions to set up one layer as a “master material” for other layers. Create a new solid, and give it a descriptive name you don’t plan to change later, such as Text Master Material (changing this name later will break the expressions you’re about to create). Turn of its Video Switch to make it invisible, and reveal its Material Options. Then reveal the Material Options for the layers you wish to slave to this master, Option+click (Alt+click) the animation stopwatch for the property you wish to slave, and use the pick whip to select the same property for your master material layer. Change the Material Options values for the master, and the slaved layers will follow.

You should now have a basic understanding of how 3D lights and layers interact in After Effects, including what parameters to experiment with to get a specific change in illumination or shift in color. In the next column in this series, we will discuss shadows, including how to control their size, sharpness and color.

Monday, September 02, 2002

Blinded by the Light

3D lighting in After Effects can be powerful, subtle…and confusing.

After Effects Goes to 11

Metal and Plastic

Master Materials