Pinning part of ‘hair’ made from objects

[Jim Coote]

I have created a hair particle system on a simple plane in which a soft body object rather than a path is rendered. I would like to be able to blow a wind or turbulence force such that the villi like shape sways gently but the bottom stays rooted. The soft body object is a path that I made into a villi shape using Animall, but I may want to try this with a converted mesh too. The objects origin is right at the bottom. The ‘hair’ system formed OK and when I apply wind the vertical object ‘hairs’ move as expected. i.e. the whole objects move in one direction. I would like  to pin the origin to the plane and ideally get the tops of the ‘hair’s to move more than the middle. Any ideas?

[spikeyxxx]

What you could do, is make your hair particle system:

then 

Then make your shape, make sure that the up direction of your object is pointing along the World Y-axis (don’t ask me why) and its origin is at the bottom of the object.

Add a Particle Instance Modifier with the Plane as Object and the Hair Particle System you made as the Particle System.  Make sure to enable Create Along Paths:

Then you can add your Force Field:

[Jim Coote]

Unfortunately the  soft body  cylinders all blow away. Is there a way that they can be made to stick to the plane?

[Adrian Bellworthy]

This should work as @spikeyxxx suggested.

[spikeyxxx]

@jimcoote just to be clear, ‘my’ method doesn’t use soft body physics!

You could assign a Vertex Group to Goal (in the Soft Body settings),, with a higher Stiffness, but that wouldn’t give you a ‘bending’ of the cylinders.

There might be a way to do this with Cloth Physics, because that has a Pressure setting and also a Pin Group (in the Shape settings), but I am not sure how to make that work.

[Jim Coote]

OK Finally got it! I was making about 3-4 mistakes at once that you couldn’t have legislated for! Little things like not turning on hair dynamics, having the ‘Keep shape’ box checked. Doh!  Have finally got it so villi bend nicely in a breeze. It was hard at first to stop them flattening. I’ve found that using just 2-3 segments on the hair, adjusting falloff, and putting the wind flow up to 10 seems to minimise this. Thanks for all your answers.

[Jim Coote]

PS: To anyone following this thread, here’s something that wasn’t obvious.  You have to build the original object so it goes in the positive direction on the Y axis. If  like me you laid it down in the  -ve direction, even after returning all rotations to zero via Ctrl A, etc,  the instances are all upside down. Shifting the origin to the other end was no help.  I only noticed this was an issue once I moved to using asymmetric objects.

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