Adopt External Guides 

This operator allows the artist to import a small set of externally simulated guides into a dense hair object and use them to drive its animation. This is similar to the concept of skinning a mesh with a skeleton where you create bones to drive the anatomy of a digital character, so your guides or "bones" should roughly match the shape of the dense hair that you want to affect or animate. Instead of simulating the guides used to generate the hair, you can save time and effort by simulating just a few external guides that will drive the movement of the final groom.

The following image shows the hair without simulated external guides assigned to it. See the external guides moving around without affecting the hair:

The following image shows the hair with a set of simulated external guides assigned to it:


Reference and Control Guides 

To be able to deform hair within current operator stack using external guides we need to have two sets of such guides:
  • Reference guides, which provide the initial state of the strands. Think of them like a T-pose for the character. These guides must not be animated and must remain in the same object-space position during animation and character movement.
  • Control guides, which specify the strand animation and movement in relation to the reference guides. The difference between these and reference guides is what will be used to actually deform the hair within the operator stack. These guides can be animated and move in object space.


Adopt External Guides operator have few and easy to use parameters and controls.

  • Strand Group
    Specifies the strand group that should be affect by the external guides. You can use this option after applying one or more Adopt External Guides operators to affect a different area of the hair with each of them.
  • Amount
    Specifies the amount of influence exerted by the external guides.
  • Assign Control Guides
    Enter the context tool that allows you to pick an external guide shape.
  • Clean Control Guides
    Clear the selected guide shape.
  • Match Control Strands by Distance
    When on, the control and reference strands will be paired by their closest respective roots. Otherwise they will be paired by strand ids.

Exporting the animation 

The resulting animation of the hair can be exported using our .abc exporter. Find step by step instructions on how to cache and export hair animations in the Animation Cache Operator page.


Using the Adopt External Guides operator 


Related Topics 

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