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Volume Select Modifier Support

 Supported in Krakatoa v1.5.0 and higher

Overview

  • The 3ds Max Volume Select modifier is a procedural selection modifier which can be used to generate a sub-object selection based on a gizmo volume or a texture map.
  • Krakatoa supports the Vertex Sub-Object Selection mode of the Volume Select modifier as a Particle Selection channel source.
  • The Box, Cylinder and Sphere Gizmo nodes and the Texture Map modes are supported.
  • The Mesh Object mode is not supported. In v1.6.0 an higher, it will be specifically ignored, in prior versions selecting a Mesh Object would cause an unrecoverable crash to desktop.
  • The Soft-Selection option is also supported.
  • The Material ID and Smoothing Groups options are not supported because the particles have no face data associated with them.

Examples

  • In the following examples, a PRT Volume was created from a Box Primitive.
  • A Volume Select modifier with various settings was used to set the Selection Channel of the particles.
  • A Krakatoa Channels Modifier with the following flow was used to colorize the particles based on their Selection:

  • In the following examples, the Volume Select was set to Vertex Level, Replace Method, Select By Box without and with Soft-Selection, while the gizmo was moved up and scaled down with Auto Fit turned off:

  • In the following examples, the Select By option was switched to Cylinder and Sphere:

  • In the following examples, the Soft-Selection was turned on and set to 30 units, then a Krakatoa Delete modifier set to Delete Selection Greater Than Zero was added to cut a hole into the PRT Volume:

  • In the following examples, a default Cellular Map was added to the Texture Map slot of the Volume Select, then its Size was changed to 25 units. The right image shows the Krakatoa Delete Modifier set to delete by Soft-Selection and ID:

Performance

  • The Volume Select modifier is easier to use than the Krakatoa Channels Modifier due to its familiarity and built-in Gizmos and User Interface controls.
  • On the other hand, the Volume Select modifier is a lot slower than a Krakatoa Channels Modifier for the same operation.
    • For example, selecting 10 million particles by default Cellular Map takes 40 seconds with Volume Select and only 18 with a KCM set to feed the Red channel of the Cellular Map into the Selection channel.
    • This is mostly due to the multi-threaded nature of KCMs.
  • The Volume Select is a good candidate when selecting particles using Box, Sphere and Cylinder Gizmos and when applying Soft-Selection.
  • It is also the better choice for quick prototyping since creating a KCM can take longer than adding and setting up a Volume Select Modifier.

SEE ALSO