PDA

View Full Version : Why doesn't FX Wind affect my hair strings?



ruud
01-08-2016, 01:51 AM
Hi,

I have a scene with long hair FiberFX connected to guiding strings (2D string) by Metalink. Now, it doesn't matter how much power I give the wind, it just won't affect my hair...

Any ideas?

Thanks,

Thomas Leitner
01-08-2016, 02:29 AM
Hi,
without knowing the scene there could be many reasons why it does not work.
A few basic things:
Do you use 2 point poly chains?
Did you apply ClothFX to the chain?
Try a preset (maybe "Thin cotton") for testing.
For testing set the wind falloff to OFF.
If you use a directional wind you have to set the direction in the vector tab.
Make a simple test setup first.

If nothing helps post a simple scene.

ciao
Thomas

ruud
01-08-2016, 02:36 AM
Hi Thomas,

A few basic things:
Do you use 2 point poly chains?
Yes, I converted my splines into 2D chains using Strandmaker

Did you apply ClothFX to the chain?
Jup, basic settings

Try a preset (maybe "Thin cotton") for testing.
Everything up to Deformation to last just to make sure...

For testing set the wind falloff to OFF.
I did, also added the wind and the cloth to the same group

If you use a directional wind you have to set the direction in the vector tab.

Make a simple test setup first.
I already did the simple scene... collision is fine, it moves and reacts to that, but the wind... still not..

Thomas Leitner
01-08-2016, 02:47 AM
....I already did the simple scene... collision is fine, it moves and reacts to that, but the wind... still not..

Hi,
can you post this simple scene to look into it?

ciao
Thomas

ruud
01-08-2016, 02:56 AM
A simple handmade 2D Poly-string works... have to be something to do with the Strandmaker tool...

ruud
01-08-2016, 03:10 AM
Got it, it was just some tweaking... don't know why it didn't show earlier...

Thanks

Greenlaw
01-08-2016, 09:36 AM
Strandmaker guides work well with Bullet Deforming. It's what I use for all my hair animations these days.

That said, I'm not 100% sure it works with Bullet wind--just haven't needed in a production yet--but it should work.

I'll take a quick look in a minute.

G.

Greenlaw
01-08-2016, 09:49 AM
Okay, I just checked and, yes, Bullet wind works fine with Strandmaker guides.

As usual, you want to set Mass Distribution to Vertices and you need to set Shape Lock to Translation and Rotation. You'll want to set a weight map that affects all strands points except the root points and set Mesh Filter to that.

Additionally, I like to apply a gradient to Shape Retention to make the hair towards the roots less affected than the ends--this make is move much more naturally and helps hold the shape closer to the head. The gradient can be based on a weight map. You can use the one that Strandmaker generates.

For the wind, just create a null an apply Forcefield to it (or whichever type of 'wind' you need.)

That should get you started.

G.

ruud
01-08-2016, 09:53 AM
At the moment it is fixed on a Weightmap (clothFX), but there LW doesn't use the falloff of the weightmap causing a hard edge where it starts to calculate.. is Bullet better in this?

Greenlaw
01-08-2016, 09:54 AM
One more tip: be sure to use non-deforming proxy objects for the head and shoulders for collision objects. These be directly parented to the bones and you should use Kinematics mode. This should make your sims very fast to calculate and they should still be reasonably accurate.

As a matter of fact, speed is the main reason I prefer Bullet to ClothFX these days. I used ClothFX for hair for nearly a decade but stopped using it as soon as Bullet Deforming mode became available.

G.

- - - Updated - - -

As mentioned above, falloff for Bullet is applied in Shape Retention.

ruud
01-08-2016, 09:56 AM
Thanks, I'll check it out!

Greenlaw
01-08-2016, 09:58 AM
In ClothFX, you can apply falloff in the Fx buttons along the left. You're mainly interested in Sub Structure and Hold Structure. The process is very tweaky and time consuming though.

Bullet can be tweaky too but I can get to the settings I need much quicker with it.

G.