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      Effect:Texture Displace
      Category:Spatial Filters
      Speed:Fast

      Description: The Texture Displace Effect is best shown in pictures, as it is probably one of the more obscure and difficult Effects in Pena to explain.

      Texture Displace takes as input a Source Texture and provides that Source Texture as output, but modified by Color 2.

      The way Color 2 modifies the Source Texture is what is significant. Instead of modifying it as a color, Color 2 spatially remaps the Source Texture.

      To show how this works... consider any photo as the Source Texture. And consider that Color 2 is black. Black has a Red, Green, and Blue of 0.0.

      Texture Displace will turn each color channel of Color 2 into a coordinate. X and Y become the same coordinate, so in this case, Red, Green, and Blue all have the coordinate of X=0.0, Y=0.0.

      Next, Texture Displace reads the Source Texture, for each color channel, at the new location. In this case, since all three are the same value, and the coordinates of all three are X=0.0, Y=0.0 the color from the lower left of the Photo will be the color for that point. If Color 2 never changes from Black, the the output to the canvas will be that lower left color from the Source Photo. It is important to notice that in this Effect, there is a huge difference if Color 2 is some varying shade of grey, or if Color 2 is some actual color.

      If Color 2 is some varying shade of grey, then the position selected from the Source Position is the same for each color channel. That will map the Source Image identically for each color channel.

      If, on the other hand, Color 2 are varying colors, then the Red, Green, and Blue values at any given time are likely to be different. This means the position read from the Source Image will be different for the Red, Green, and Blue channels. This will cause the Source Image to fracture in RGB space, resulting in the image being spatially relocated differently in each color channel.

      It is possible to use this Effect to do some very interesting Image Processing. It is also possible to use this Effect to create totally new textures and defy explanation.

      In our Examples below we show a number of combinations of Source Textures and Color 2 with detailed explanations of what is happening.

       
      Options: The Texture Displace Effect has the following Options Pane:

      Source Texture:Use this to select the Texture Slot you want to user from the Texture Pane. The dark green circle is the currently selected Texture, the lighter yellowish circles are not selected. Remember that any Texture slot can contain either a Photo from your Photo Album, or Noise. The Texture slot you pick does not have to have a Texture in it yet - however, if you try to paint you will get a warning that you need to load a missing Texture.
      Horizontal Offset:This value is added to the X (horizontal) displacement for each color channel.
      Vertical Offset:This value is added to the Y (vertical) displacement for each color channel.
      Displace Red:If set to a Red X the Red Channel is not displaced. This will result in the Red Channel of the Source Texture being untouched. When set to a Green Check Mark the Red Channel is displaced.
      Displace Green:If set to a Red X the Green Channel is not displaced. This will result in the Green Channel of the Source Texture being untouched. When set to a Green Check Mark the Green Channel is displaced.
      Displace Blue:If set to a Red X the Blue Channel is not displaced. This will result in the Blue Channel of the Source Texture being untouched. When set to a Green Check Mark the Blue Channel is displaced.
      Displace Alpha:If set to a Red X the Alpha Channel is not displaced. This will result in the Alpha Channel of the Source Texture being untouched. When set to a Green Check Mark the Alpha Channel is displaced.
      Output Color 1:By default this is set to REPLACE which means that the set color will be output to Color 1. You can change this as explained in Options Pane Color Mixers.
      Output Color 2:By default this is set to IGNORE which means that the Color 2 will be ignored (the original Color 2 will be kept). You can change this as explained in Options Pane Color Mixers.

      Example: We start with a simple example. Our Source Image is our Arches National Park photo that we have loaded into a Texture Slot. In our Slot 1 we load the 4-Color Gradient Effect and with Output Color 1 set to Ignore, Output Color 2 set to Replace, and we set the LL Color to black, the UR Color to white, the UL and LR Colors to a medium grey. The result is the image on the right below:

      In Slot 2 we load our Texture Displace with default values. We get this as a result:

      First, because we had a grey gradient for Color 2, the Source Image mapped the same in the Red, Green, and Blue Channels. That kept the result more cohesive (just wait, you'll see in a moment what happens when we don't use a grey Color 2).

      Again, Color 2 is a map of how the pixels in the Source Image are repositioned on the screen. Since there are many of the same color in Color 2, some pixels in the Source Image will be referenced multiple times for a single point.

      You can see that the result was highly distorted and to the left of the Canvas. We can use the Horizontal Offset option to move it to the right, exposing more of the Effect:

      So what happens if our Color 2 is not a grey? Consider the following Source Image and Color 2, which in this case is the a 4-Color Gradient:

      Here is the result using a default Texture Displace:

      Unlike the grey gradient, which kept the image more cohesive (using the term very loosely), using a color image, in our case a 4-Color Gradient, split each color channel in the Source Texture. The Red, Green, and Blue channels of the photo were all mapped independently.

      What happens if we switch our Source Texture and Color 2? Let's try it with both the grey gradient and color gradient:

      With our Source Texture the grey gradient and our Color 2 the photo Texture, we get this:

      Now that is cohesive. But why? It is because we were using a gradient. The map is now the photo, so all we are doing is reassigning the position of the gradient to new areas. This recolors the gradient and repositions the gradient, giving a brand new photo.

      Here is the same thing with the Source Texture our 4-Color colorful gradient:

      And this combination results in this:

      Again, because our Source Texture is a color gradient it remains cohesive. The resulting image is colored completely by the Source Texture (no color is coming from the Photo in Color 2). However, the colors are no longer the same as the gradient because the different R, G and B values in Color 2 reassigned the R, G, and B values of the gradient.

      Let's examine why the gradient made all the difference. What happens if we have both the Source Texture and Color 2 the same Photo:

      Here is the highly non-cohesive result:

      An interesting, though messy result. But also a good example of the difference of a gradient versus a photo.

      In our final example we use our photo as the Source Texture and for Color 2 we use Clouds, Marble, and Granite:

      This gives us a very interesting result, almost a stone-like pattern:

       

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