How to install:

• Download and unzip the Cloudgen folder.

• After unzipping the folder, open any other .blend file, and navigate to preferences (edit＞preferences＞file paths)

  
  

  
  

  
  

  
  

  
  

  
  

  
  

  
  

• Click the + icon to add a new asset library and navigate to the unzipped Cloudgen folder. Select the folder and add it.

• Save preferences.

• Now, If you navigate to the asset browser, you will be able to find both the geometry nodes system and the shader, which you can drag and drop onto your base object.

Using the addon:

• Once you have added the geometry nodes system and shader to the mesh, you need to add an empty to the scene (shift+a＞empty＞plain axes)

• Then open the shader editor, open the cloud shader and choose the empty you created in the texture coordinate node.

  
  

• The cloud bottom is made less dense and more wispy based on the scale and position of the empty. If you scale the empty up, you get a softer fade on the bottom of the cloud and vice versa. Moving the empty up and down changes the level at which the fade occurs (tip: if you don’t want the fade at all, just move it below the cloud.

• Changing the detail of the cloud: the amount of detail on the cloud is controlled by the scale of the base mesh. This prevents the user from having to make the geometry nodes system single-user any time they want one cloud to have more or less detail. To achieve more detail on your cloud, simply scale the base mesh up and apply scale (Ctrl+a＞scale). Start very small and work up―applying large scales can quickly overwhelm your computer! Also note that if you want your cloud to be a different size after the detail is right, you can simply scale it but not apply the new scale this time.

• If you can’t see the cloud: try moving the empty up/down until it is visible.

• Pro tip: if you want a lot of clouds, you can often just apply the modifier to one or two base meshes and then duplicate these, move them around, and rotate them to give the illusion of being different. (if you use the Alt+d shortcut to duplicate instead of the normal shortcut, they will be instances of the original object and much easier on your computer.

• Volume bounces/ray depth: The more volume bounces you have in your scene (set under render settings>light paths>volume) the better your clouds will look, but the longer they will take to render. I recommend starting with a value of 12 and adjusting as needed. The ray depth setting on the cloud shader is set right for 12 bounces, but you may need to adjust it if you change the number of scene volume bounces. What this value does is that it allows light to pass through the thinner areas of the cloud, resulting in this effect:

  
  

  If you change the volume bounces and don’t see this happening, you can change the ray depth until it starts to happen again. Usually it works best to start equal to the number of volume bounces and then increase if needed. The cloud lightness/darkness value controls the strength of this effect, with the effect most apparent when this value is 0 and least when it is 1.