# Clouds Effect
The Clouds effect allows you to add simple moving clouds to your image. They can be displayed in a flat manner or even with perspective distortion. You can also fully tweak their colors, size and sharpness.
# Effect Settings
- Blend mode: This allows you to control how the clouds will be blended with the image. Usually the normal or add blend mode will be the most useful.
- Shading: This option controls whether the clouds will look lit, with dark areas, or fully white, for example.
- Write alpha: Enabling this option will make the background image only be visible where the clouds are.
- Albedo: This texture is the standard noise texture used to generate the clouds.
- Opacity mask: The opacity mask allows you to limit the effect to only certain parts of the image.
- Alpha: The total opacity of the clouds.
- Color start: This is the core color of the clouds, that will be used in places where the clouds are fully visible.
- Color end: This is the outer color of the clouds, used where the clouds are transparent. You can use these color options to colorize the fringe area of the clouds.
- Feather: Determines how much of the cloud texture will be blended in opacity. Reducing this option will make the edge of the clouds sharper.
- Scale: The size of the albedo texture. There are 4 options because the texture is sampled twice and you can scale both samples along the X and Y axis. So the Z and W values correspond to the scaling of the second texture sample.
- Smoothness: This changes the smoothness of the albedo texture.
- Speed: How fast both of the cloud textures move along the X and Y axes.
- Threshold: This is the sharp edge of the clouds. If you reduced the feather option, you can use this to change where the clouds will be cut off.
# Perspective Clouds
- Perspective: This option determines whether you want to enable perspective distortion for the clouds. You will have to adjust the perspective warp parameters in order to achieve a nice effect.
- Perspective warp: These values control how much the clouds get compressed near each border of the image. If want to animate a perspective sky, for example, you can use the values
-0.3 0 0.45 0which will compress the clouds at the bottom and stretch them at the top. You will also need to increase the Y and W components of the scale option. Finally, use the opacity mask to make sure the clouds are only displayed at the top of the image.