How to make clouds

Create clouds using volumes

  • Create a geometry object.

  • Append an IsoOffset node at the geometry level.

    Make sure you set the Output Type to SDF Volume, and the Invert Sign checkbox is turned on. Increasing the Sampling Divs provides better quality in more detailed volumes.

  • Append a Volume Mix node.

    Change the Mix Method to User so that you can enter your own expression as the Value. For example, clamp($V*10, 0, 1).

  • Set up lights and a camera.

    If you want shadows, set the Shadow Type parameter on your light node to Depth Map Shadows. Using depth map shadows is much faster than ray traced shadows.

  • Use one of the volume materials on the Material Palette.

    Tip

    Billowy Smoke is useful because it has noise parameters.

    Note

    You cannot drag and drop this material in the viewport like you can for other materials. You must point to it on the Material tab of the object.

  • You can also create an Instance Object to instance your original geometry onto several points.

    For example, inside the instance object you could create a grid and append a scatter node. On the Instance tab of the Instance Object, make sure you turn on the Point Instancing checkbox, and point to your object in the Instance Object parameter.

Creating clouds using i3ds

  • Create an array of still particles to represent a cloud.

  • Create a metacloud shader in the SHOP network.

  • In the Output network, create a 3D Texture Generator to drive the image3d program that generates 3D texture maps.

    On this node, set the following parameters:

    • Output Image - to where you would like to output your .i3d files

    • SHOP - to your metacloud

    • Render As - to Raw point geometry

    • SOP - to the particle array

    • Turn on the Verbose checkbox

    Click the Render button.

  • Return to the SHOP network and create a Mantra: Image 3D Volume Procedural and set the I3D File parameter to the .i3d file that was just created.

  • At the object level, create a geometry object and apply a Billowy Smoke material. On the Geometry sub-tab of the Render tab on the object, set the Procedural Shader to the Image 3D Volume Procedural shader, which will render the .i3d file directly.

Tips

  • The Volume Step Size parameter on the Mantra node controls the level of detail in volumetric clouds. The lower the step size, the greater the detail.

  • Using shadows will make your cloud look more realistic. Set the Shadow Type to Ray-Traced Shadows on the Shadows tab of your light node.