= Common image effects =

See also [how to distort or convolve an image|distort] .

== Glow ==

    [Image:images/glow.jpg]

    To create a glow effect, blur the bright parts of the image.

    steps>>
        # Use the [Lumakey operator|Node:cop2/lumakey] to extract the
          bright parts of the image as a  [matte|/composite/mattes] .

        # Use a [Bright operator|Node:cop2/bright] to increase the
          brightness of the extracted matte (because the blurring step
          will dim it back down).

        # Use a  [blur node|/composite/blur_sharpen]  to blur the matte. The blur
          softens the highlights, and basically determines the amount of
          glow.

        #  [Combine|/composite/layers]  the blurred matte back over the
          original image.

== Drop shadow ==

    [Image:images/dropshadow.jpg]

    steps>>
        # Use the [Channel Copy operator|Node:cop2/channelcopy] to set
          the Color channel to black (or whatever color you want for the
          shadow).

        # Use a  [blur node|/composite/blur_sharpen]  to blur the shadow.

        # Use the [Transform operator|Node:cop2/xform] to offset the
          shadow.

        #  [Combine|/composite/layers]  the original image over the shadow.

== Blurs ==

    See  [how to blur and sharpen images|/composite/blur_sharpen] .

== Emboss ==

    The [Emboss operator|Node:cop2/emboss] can fake lighting by using
    luminance to extract bumps, and apply specular highlights.

    [Image:images/emboss.jpg]

    If you already have a bump map, connect it to the second input of
    Emboss to override the automatic bump detection.


    TIP:
        For more advanced embossing, use the [Lighting
        operator|Node:cop2/light] with bump mapped lighting. The
        Lighting COP can add atmospheric effects as well.

== Fake caustics ==

    [Image:images/fake_caustics.jpg]

    Caustics are made up of several layers of luminance noise.

    * The base layer is a gradual modulation of brightness. This is best
      accomplished with alligator noise, which produces the cell-like
      quality of underwater caustics.

    * The specular layer is made up of sharp spikes of focused light.
      This can be done by edge detecting the noise to extract prominent
      lines, and then pulling out the brightest parts. Adjust the gamma
      to further pull specks out of the lines, and then blur slightly to
      avoid pixelation.

    * Multiply the image by the base layer, and use over or screen to
      composite the specular highlights in.

    [Image:images/caustics.jpg]

== Fake table-top reflection ==

    [Image:images/reflect_net.jpg]

    steps>>
        # Create the reflection with the [Pin operator|Node:cop2/pin].
          Move the corners so they form an upside-down trapezoid, with
          the bottom along the axis of reflection.

        # To blur the reflection, use the [Ramp operator|Node:cop2/ramp]
          to create a vertical ramp fill with black at the axis of
          reflection, increasing to white away from the axis. Connect
          this to the  [mask input|/nodes/cop2]  of a  [blur
          node|/composite/blur_sharpen]  (with per-pixel on). This blurs little at the
          closest point of reflection (black in the mask) and more
          further away (white in the mask). Adjust the blur amount.

        # Use an [HSV operator|Node:cop2/hsv] to reduce the saturation
          of the reflection. Use a [Bright operator|Node:cop2/bright] to
          dim the reflection to make it more subtle. You can also use a
          [Gamma operator|Node:cop2/gamma] to wash out the reflection.

        #  [Combine|/composite/layers]  the reflection, the original image,
          and any background plates.

    [Image:images/reflect.jpg]

== Borders ==

    Use the [Border operator|Node:cop2/border] to a solid color border
    around the image, either by increasing the resolution to accommodate
    the border, or by overwriting some of the edge information.