Hair-Force 1

Hair-Force tutorial. This tutorial will help you blow away your lawn.

Heavy pages coming up!

Follow up:

This tutorial is specifically about grass with Hair and particle Forces.
I will not get into the Grass itself as there is a specific tutorial about that in the Hair section of this site. Grass & Flowers with Hair
What we want to make here is a wind flowing over a field of grass.
In the next pages I'll also show what other forces you can apply to tho Hair.

First of all we will start with a plane or a circle or a landscape object to apply the Hair on.
I've tested two main setups with completely different results.
The first setup is with Hair as it is, the second is with Hair with a reversed gravity (9.81, without the minus), the second setup is nice straight grass. And the first (which I like a lot) is more like wet and messy grass.

hair-force-gravity

I've also tested some setups with two Hair objects, the second Hair is much higher and sparser.

hair-force-1or2objects

As a general remark I would like to say that this whole setup took quite a long time to get done right.
There is a lot of fiddling the parameters to get approximately what you want.

What I basically did is to add several Wind objects (classic Particle forces)

wind-vibrate

The wind objects I used here have a force of 60 an unlimited size and I enabled the Falloff (this is important) and set its size as to have the wind objects intersect each-other .

wind-param

Next step (for animation) is to randomize the wind a bit. I added a Vibrate tag to each wind. The Vibrate is set to rotate 180 degrees with a low frequency of 0.4. or lower.
To finalize the randomization I grouped all the Wind objects in one Null and added another Vibrate tag on that group.
Have a test run (play) to see the result. (fewer guides make a faster preview)

The first movie has a normal gravity (-9.81) the second one has the reversed gravity (9.81 upwards)

This is only one way of doing the trick. You could also move the Wind objects on specific paths as to get a better control over them.

On the next pages I'll show some results I got with different setups and different forces.

Pages: 1 · 2 · 3 · 4 · 5


17 comments

Comment from: hal [Visitor] Email : 2009-01-15 @ 05:07
*****
So looking forward to this!!!
Comment from: Tom [Visitor] · http://www.thomas-aull.de : 2009-01-15 @ 10:42
*****
Great!
Comment from: BerTiN [Visitor] · http://polygone-production.com : 2009-01-16 @ 16:34
It's dechiring its race, Base !

As usual, always some very great stuff you show us .
Comment from: Morpheus [Visitor] : 2009-01-16 @ 20:42
Great stuff M8.

Morph
Comment from: Kathie Berry [Visitor] · http://www.berry-designs.com/wordpress : 2009-01-20 @ 22:46
Terrific!! Thank you, that's a lot of fun!
Comment from: base80 [Member] Email : 2009-01-22 @ 03:18
@Morpheus
Call me M80 :-)
Comment from: nomadgio [Visitor] Email : 2009-02-05 @ 01:27
Fantastic Tutorial!
I'd been trying a few things out but thanks to you
my scene now looks alive, Cheers!!!
Comment from: Leah [Visitor] · http://www.leahraeder.com/ : 2009-04-05 @ 06:27
*****
Very useful. Thanks!
Comment from: patrick [Visitor] : 2009-09-03 @ 02:03
*----
This is not a tutorial what so ever its neat but i dont know what u did to shorten the hairs or to texture it.
Comment from: Scott [Visitor] : 2009-10-27 @ 14:35
*****
I setup my hair object, add a classic wind object and it works, but the hair just seems to continue falling until it reaches a rest state. I can't achieve a back and fourth, natural movement like you have in your animation. I thought maybe the gravity setting was too high...but I have tried various and it always plays in the same way.
Comment from: base80 [Member] Email : 2009-10-27 @ 14:39
At the end of the tutorial I said : "The first movie has a normal gravity (-9.81) the second one has the reversed gravity (9.81 upwards)"

Or hit the "Rigid" checkbox
Comment from: noori [Visitor] : 2010-01-12 @ 19:33
*****
thanks alot. they are all great tuts.
I learned alot of stuf from your websit.
keep going on man
Comment from: Elias Huch [Visitor] · http://reelvizion.info : 2010-02-12 @ 21:10
****-
OK,
So I've done all of the steps and still nothing. I can't seem to find where you adjust the gravity in any of the tags or attributes. I'm guessing that is my problem, since it's the only thing I cannot figure out. Could someone direct me there?
Comment from: base80 [Member] Email : 2010-02-13 @ 20:01
Gravity is an object from the particle system
Comment from: Term Paper [Visitor] · http://www.flashpapers.com : 2010-02-17 @ 11:47
*****
Hi, thanks for the tips. That was a great help to me.I really like this blog, It's always nice when you can not only be informed, but also get knowledge, from these type of blog, nice entry. Thanks
Comment from: Matthrw [Visitor] · http://www.nonplagiarizedessays.co.uk : 2010-06-22 @ 11:54
I’ve been most successful using your last suggestion. Nothing else has worked. I’m unable to “stack” these for some reason, so I’d love to figure that out, but thanks for the tips so far.
Comment from: NDawgg [Visitor] Email · http://studentsites.expression.edu/~nfegette : 2010-06-30 @ 00:44
****-
Great tutorial! However I don't see how you were able to direct the wind flow to just effect the small range around the object. When I place the wind above the grass even in its smallest form (with falloff) it still manages to blow the entire patch over. If you could get back to me with an answer it would be greatly appreciated. Thank you so much.

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