View Full Version : Wind Effect for Fiber FX

07-13-2019, 10:25 AM

Can anyone explain how do I set this kind of effect for grass with fiber fx ?

thanks for your time :hey:

07-13-2019, 11:00 AM
The absolute simplest way is to use dynamic gravity..

In fiberfx geometry tab, check dynamic gravity, then enter the gravity channel
"T" button and add a ripple procedural texture.

set desired wave amount and scale and wave speed, a little tweaking is needed
to get it right.

you can also reference a moving null object to any procedural to have the texture deform more like localized and or moving in a certain direction.

This works without any true geometry strands thus calculating fast.
Drawbacks is that it will not collide with any other items.

If you want that you need to add true fiberfx polychains/strandmaker etc..and use ripple
..You could use ripple displacement on the strands, but then it will not
by colliding either..it will overide such dynamics.

for true dynamics you would want to affect the fiberstrands with
either clothFX or us the new bullet system, add forces from bullet or clothfx and use old legacy winds.

The sample you posted does have too much of overall movement on larger grass patches..thus several individual blades moves exactly as their neighbour blades, and that isnīt realistic, ideally you want each blade almost to
move differently..but at the same time have yet another effector moving larger patches, this is due to every individual blades weight, shape and structure that holds such variance.


07-13-2019, 11:57 AM
thank you again always quick to help out enjoy your day further cheers :beerchug:

07-15-2019, 01:17 PM
I hope you managed to get some things going?

I need to clarify some things..
You do not need to enter gravity channel and set texture animations from there, you can also for instance add a ripple texture in styling/swirl turns channel, but you also need to have swirl set at a certain value for it to work, and you need dynamic gravity checked as well ..or the procedurals wonīt work no matter which channel you add procedurals on for animated effects.

Same goes for setting a value of zero for scale or random scale and adding a ripple procedural texture in those channels, you need to have dynamic gravity checked for it to animate, hit play and see the fibers grow and retract.

And a tip would be to use dynamic gravity when you set a gravity value...and hit play, that will result in direct feedback on the gravity when you change the gravity value, as opposed to not having use dynamic gravity..it will take a little longer for the values to yield feedback when tweaking it without dynamic gravity, so click play and then drag gravity values with dynamic gravity checked.

07-16-2019, 01:58 PM

well this worked out smoothly with 50% ripple on dyna gravity .... just fiber fx is abit too slow to preview in opengl is it same for you ?

07-16-2019, 05:11 PM

well this worked out smoothly with 50% ripple on dyna gravity .... just fiber fx is abit too slow to preview in opengl is it same for you ?

Depends on amount of fibers and edges , here a simple grass patch of 4000 fibers 64000 edges plays in realtime, while runnin 10 000 fibers and 160 000 edges makes it play sligthly slower.

20 000 fibers and 320 000 edges, and it start to play with step movements, hard to say FPS..but itīs tolerable.

It depends on your machine also I guess.

The worse part will be the rendering, I canīt stand it and will probably focus solely on rendering in blender..which runs circles around Lightwave when it comes to rendering hair, I now know the pipeline so that I can generate fiberfx hair in layout lightwave or draw spline curves in modeler, and use both those methods to send to lightwave and use it as main strands in blender..and render there.
I can even continue to comb and cut hair with particle edit in blender based on lighwave strands.