Missing manual info: how to use Weight tool to style Hair in Particle Edit mode

Summary:

  • Play the animation through to its end*, to make blender calculate hair movement
  • Go to last frame*
  • Switch to Particle Edit mode
  • Paint with Weight tool
  • Lower the Weight’s tool’s strength to make hair heavier

When you’re styling Hair, in Particle Edit mode, you might wonder what the Weight tool does. It is not explained in the manual, except for a cryptic “A keypoint with a weight of 1 will not move at all, a keypoint with a weight of 0 subjects fully to softbody animation. This value is scaled by the GMin - GMax range of softbody goals…” That’s found under the wrong title, too.

It tells nothing about where this Gmin-Gmax thing is, or why any of this has anything to do with hair.

It’s anybody’s guess how to edit “Weight,” or how to undo it. I was lucky enough to guess:

you have to lower the weight tool’s strength and repaint, to make hair heavier. That’s what changes the ‘weight’ that the tool paints onto your hairs.

But it doesn’t show you what you’re painting unless you have already played the animation at least once, to force blender to simulate the hair physics. THEN, you must fast-forward to the last frame.* ONLY THEN will the colors of hair weights appear when you’re in Particle Edit mode. Not on frame 1, not on frame 0, but on the last frame.*

To change weights, repaint with a different weight setting. Ah, but where’s the Weight setting? It’s the brush’s ‘Strength’.

The higher the “Strength” number, the lower the weight of the hair. Makes sense, right? Lower this number to make hairs heavier, and paint the lower weight onto the hairs you want to change. Raise the number to make hairs lighter, and paint again.

Exit Particle Edit mode, play the animation to force it to recalculate the hair motion, and see how the hair settles. Go back to Particle Edit mode and repeat.

Hope this saves some of you the tedious manual digging and trial-and-error I went thru tonight.

*I only used 100 frames of ‘pre-roll’ to let the hair settle. I don’t know if you really need more frames while you’re styling the hair.

1 Like