About Exposure Fill Using Render Change
A frequent effect applied at the compositing stage is texture overlay. Either a shaky textured line will be applied on an animation or colour fills will be replaced with textures. Most of these effects are created using the Colour Override effect—see Colour-Override Node.
You can replace a colour fill with a static or animated texture. For an animated texture, you can fill a character's wool sweater with four or five variations, filling the sweater zone and loop it throughout the sequence. This way the final animation can have a bit more of an organic style with moving textures and shaking lines.
You might also want to control when the textures move. When your character is still, you might want the texture to remain still as well. You could also want the texture to remain still if the character only moves slightly. You can control when the texture will move based on the animation motion. You can set the parameters that define what is considered a big enough change for the texture to start moving.
The motion analysis is based on the rendered images sent to a Display node. You can use the main Display node set below your final Composite node or add a specific Display node to analyze a specific portion of your node system, such as a character's sweater layers—see About Displays.
The Exposure Fill Using Render Change command can be applied on any drawing or bitmap layer, but the most common case where this feature will be used is on a bitmap or drawing layer connected in a Colour-Override's texture port—see Overriding a Colour with a Bitmap Image Sequence. The overridden colours should use the Texture - Use Image Input setting. Note that you might need to parent your character's master peg to the texture layer for the texture animation to follow your character.