Layer effects layer-effects

Photoshop-style layer shadow and glow effects are implemented using special sub-layers (effect layers) which can be attached to any layer (the parent layer), including layer=0 and layer=comp.

While effect layers support a number of standard image and layer attributes and commands, they are not intended to be general purpose layers and do not support independent image or text data.

Any number of layer effects can be attached to a single parent layer.

Inner and outer effects section-2dade7ee98e041d1b4d1725e6f98a515

Inner effects are rendered on top of the parent layer, and are visible only in opaque areas of the parent layer. Outer effects are rendered behind the parent layer (thus they are never visible within opaque areas of the parent layer) and can be positioned anywhere within the compositing canvas. An inner or outer effect is chosen by assigning a positive or negative effect layer number with the effect= command. The effect= command also controls the z-ordering amongst multiple effect layers attached to the same parent layer.

Relationship to parent layer section-eb8bfc4f754a42fc973b562821d6f2d3

Effect layers are automatically sized and positioned to coincide with the parent layer (that is, the effect layer inherits the size= and origin= values of the parent layer). pos= can be used to shift the effect layer away from the parent layer, as is typically required for drop and inner shadow effects. While for standard layers pos= specifies an offset between the origins of this layer and layer 0, for effect layers pos= specifies the offset between the origins of the effect layer and the parent layer.

Supported commands and attributes section-035fc6bcba7d4e7ab4bd46687c1d8879

Effect layers accept the following commands and attributes:

  • blendMode=
  • effect=
  • color=
  • maskUse=
  • opac=
  • op_grow=
  • op_blur=
  • op_noise=
  • pos=

All other image and layer commands contained in effect layers are ignored.

Default effect macros section-a01e8dcc87c94495b54a6dfb21d2a718

To facilitate layer effects use, IS provides two macros with the default image catalog, $shadow$ and $glow$, which provide default values for effect layer attributes which are similar to Photoshop layer effects. The following table lists which effect command and macro should be used to implement the default layer effects. Naturally, any of the attributes specified in the macros can be modified in the URL, or alternative macros can be created to implement custom layer effects.

Desired effect
Drop Shadow
Inner Shadow
Outer Glow
Inner Glow

Examples section-4c449fdf707b43858917fb271fa1fe96

Add a three pixel wide, red border with 50% opacity to a layer:


The border follows the contours of the image’s alpha channel or mask. Setting effect=1 would place the border on the inside edge instead.

Add a bluish drop shadow to an image, using the default effect settings (except for the color):


extend= adds a little margin to the bottom right edges of the image, which prevents the drop shadow from being clipped to the image bounds.

See also section-1acccccf534549aea23d4c008c17e7c0

effect=, Command Macros%l94560