Weathervane?

A while ago I saw that someone had made a script that spawned a grid over an entire zone of small arrows every 10m that pointed in the wind direction. Viewed from above it was neat to awtch the wind patterns.

Anyways.... is there perhaps a script on a timer out there to point an object towards the wind direction to make a weathervane object? Would be very nice for the ranch I'm helping work on.

Here is a script that will simply make the object turn to face the wind direction every 2 seconds.

default
{
	state_entry()
	{
		llSetTimerEvent(2);
	}
	
	timer()
	{
		llLookAt(llWind(<0,0,0>),10,10);
	}
}

Just make sure that it is in the root prim of an object. If this doesn't work please let me know as I am writing this from work, and there may be something I am forgetting.

A weathervane was my very first build in SL!

I've seen a pretty cool weather gadget around Phobos... I believe it belonged to Hank Ramos? Anyway, in addition to pointing into the wind, it included an anemometer. That's the thing that spins around measuring windspeed.

We have wind?

Really?

What's it do?

Um... blows?

Hehe.

// w00t stupid tumbleweed script!
// Rez a wood ball and drop this innit.
// Now I just need a tumbleweed texture that isn't teh suck. ^^

float tweakvalue = 0.5 ;	// The fraction of the wind speed you want the tumbleweed to move at.

default
{
	state_entry()
	{
		llSetStatus( STATUS_PHYSICS | STATUS_DIE_AT_EDGE, TRUE ) ;
		llCollisionSound( "", 0.0 ) ;   // I wish people would remember this!
		
		llSetTimerEvent( 2 ) ;
	}
	
	timer()
	{
		llApplyImpulse( llWind( ZERO_VECTOR ) * ( tweakvalue * llGetMass() ), FALSE ) ;
	}
}

But does this mean people could make real working sail boats? How about kites?

Oooh! A kite! I wanna make one, now.

Probably what you'd want to do is have the kite object use llSetHoverHeight() or something along those lines, to get it up in the air, then ... well, heck, even my tumbleweed script would probably cause it to blow around.

Ummm... now, constraining the motion of the kite (so it doesn't fly away), and keeping it oriented correctly (pointing its bottom toward the user) could be an interesting exercise... okay, now I hafta do this when I get home tonight.

BTW, Aestival is a neat name. I like that word. ^^

Thank you! *^^*

/me wants a kite!

Hey Cross,
I started on a line of kites a while back.
Hopefully I can catch up with you in-world later.

L8r,
UU

I was just fooling with a similar script the other day when I realized that the wind never has a value in the Z force... I guess I'm not gonna be catching a thermal anytime soon.

I tried making a physics-based anemometer once becauseI was curious about the wind...I wanted to see if the wind in SL had any physical force.

I still don't know if it has force and I have a weird spinny gadget gathering dust in my inventory.

But basicly, it's four cups on sticks attached with a hinge to a pole, with a base that has directional points indicated on it. It's scripted to display the result of llGetWind in floating text (updated every 5 seconds or so) and I threw in a particle generator for a visual reference of wind direction because I didn't know how to derive direction from the llWind function.

What is the unit of velocity in SL anyway? Meters per second?

Yeah, we have wind and clouds, they are based on cellular automata.
http://en.wikipedia.org/wiki/Cellular_automata

Wind has velocity, but applies no force to anything, unless those anythings are scripted to push themselves around based on the wind velocity. llWind returns a vector representing the wind velocity (speed and direction). If you want a unit vector (ie. direction only, magnitude of 1.0), use llVecNorm( llWind() ).

As far as I know, everything in SL is metricish, so yeah, meters per second.

Edit: Oops, applies no force to anything except particles that are flagged with PSYS_PART_WIND_MASK, I should say.

is the good for a cape ( when flying around )

Hey wow... you probably could make a pretty decent 'wind-blown' cape using wind-responsive particles.

It actually applies force to objects that are light enough. I made a bunch of butterflies that flit using llApplyImpulse in a random direction. The wind intoduced a strong bias to their motion

- C

yea yea, bump :^)

Actually, when I just tried this, the prim sort of flopped over on it's side at a wierd angle. What would be nice is if you could lock the X and Y axis rotations, and just have it rotate around the Z (up/down) axis.

Problem is, llLookAt() points the Z-axis. So, the simple solution is to build your object with that in mind and you'll get the same result that you're looking for. Whichever axis becomes the new "Up" axis will become the pivot, with the remaining two locked.

how about 'hot-air' ballooning?? would that be possible? does the atmospheric model include barometric densities?

The wind in SL is highly erratic and changes constantly. It's not really good for much. It's like a feature they started to add, got wrong, but never bothered to fix/finish since it's not used for much and the errors are all that obvious... Until you try to USE the wind for something.

And the wind has no connection to physics whatsoever. Only trees and any script that asks for it will be affected by "wind".