- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report
I have a rigged character doing a simple animation that bobs the head up and down in order to do a hair replacement VFX shot over a plate of a real-life actor. On the character's scalp, I created a classic Xgen groom from guides sculpted to match the real character's long, middle-parted wavy hair pattern that hangs in front of the shoulders. I then used the AnimWires modifier to create wires from the guides and made them dynamic.
Everything's working fine, the scale is correct in the solver, the wires and hairs are colliding, stretching is turned off, but I'm having trouble making the wires hold their shape without straightening from either the gravity itself or the occasional faster move of the head tugging on them and straightening them out.
Increasing bend/twist resistance to ridiculous numbers only seems to slow the simulation down without stopping the wires from losing their curves; switching the "Bend Model" to "Twist tracking" has no visible effect whatsoever either.
The only workaround solution I've found was to use the Start Curve Attract scale ramp to progressively make the wires stiffer near the roots and more dynamic near the tips, but this makes it so that when the character tips their head forwards, the hair starts defying gravity due to the initial section of the wires being attracted to the input curves. What's more, the curves in front of the shoulders will clip into the body as the head tilts forward, causing the collisions to struggle a bit between following the input curves and keeping out of the way of the mesh. And if I lower the attraction to allow for the wires to better move out of the way of the mesh, the hair just becomes too fluid and straightened.
I found a passable middle ground but it still makes the hair movement unnatural because the tips move too much compared to the rest. My goal is to have the hair be generally stiff in terms of dynamics, while still falling down with gravity as the character tilts their head.
I've tried manually creating a wavy curve in the same scale, making it dynamic, and attaching it to the scalp, and I had no problem then. By enabling Twist Tracking and just raising bend and twist resistance slightly, the output curve was able to keep its wavy shape while still falling down with gravity as the head bobbed and tilted. But when using the several curves from the guides it seems to have trouble keeping the shape.
I've also tried creating these wires in several ways, including manually creating the dynamic wires through the nhair menu from curves created from the guides and attaching the wires afterward, to converting the guides to curves, making a cache, and converting them back to guides without using the AnimWire modifier. The result is always the same.
Is this a limitation of the hairsystem dynamics, that once a large number of curves is being simulated it just can't maintain the original shapes of the curves, or am I experiencing some sort of bug? What am I missing?
Solved! Go to Solution.