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Jop StrandTool

Jop StrandTool Logo


This digital asset is intented to build multiple strands based on other Jop Tools.

Plugged after another Jop Tool in "Curves" mode, it will create multiple strands from the yarns.
You'll then be able to add tip displacement and noise while preserving underleying yarns animation.


Please make sure that the previous tool is in "Curves" mode or no strands will be generated.


This tool may generate a lot of strands based on the source curves you provide.
As a result it is not meant to be rendered as mesh geometry, so no meshing option is provided.


  • Curves Input: Yarns to build strands from.
    Expects curves form another Jop Tool.


    You may actually plug in any polyline as soon as it carries some specific attributes.

    • Primitive
      • id(int) : an unique curve identifier
      • curverdm(float) : a random 0-1 pern yarn value
      • localGrow(float) : per yarn 0-1 animation completion
    • Point
      • curveu(float) : u coordinate relative to uncarved curve length
      • normU(float) : u coordinate relative to carved curve length
      • width(float) : the width of the yarns
      • transform(3x3 matrix) : point orientaion 3x3 matrix
      • UV(vector), optional : the point Texture UV coordinates, will be moved to "uv2" attribute
      • cut(group), optional : every points in that group will be deleted
    • Detail
      • curve(int) : have to be set to 1



  • Color Attribute : Choose the attribute to output as color (Cd).

  • Colorize : Colorize the random attribute.

  • Checker : Preview checkboard while in UV mode.

  • Max Frames to Cache : Maximum frames to keep in cache, timeline length as default.

  • Clear : Reset the cache.

  • Preview 1 yarn : Enable computing of only one yarn, usefull to preserve performances while tweaking animation.
    Choose which yarn number to compute.


  • Override Yarn Width : Let you override the width of the yarns, otherwise keep the width from the upstream nodes.


    To enable shaded yarns display in the viewport while in curve mode, enable "Shade Open Curves In Viewport" in the Geo's "Misc" tab.

  • Strand Count : The strand count by yarn.

  • Twist : Twisting of the yarn.

  • Subdivision : Set the global strands subdivision count.

Tip Spread#

  • Enable : Enable the tip displace.

  • Smooth Tips : Smooth tips points positions.

  • Spread

    • Strength : The tip spread global multiplier.
    • Min. Variation : Per strand minimum displace variation.
    • Max. Variation : Per strand maximum displace variation.
    • Seed : Displace variation seed.
    • Grow Fade : Displace fading curve over animation length.
  • Curve

    • Tip Curve : Displace multiplier curve along the strands.
    • Variation : Per strand tip curve variation.
    • Seed : Curve variation seed.
  • Noise

    • Strength : The strength of the tip noise.
    • Frequency : The frequency of the tip noise.
    • Seed : The random seed of the tip noise.