Increase FLIP viscosity with particle age?

[bentway23]

How would one increase FLIP viscosity based on particle age, to get a thickening/coagulating effect? My searching only found one how-to from 2012, which doesn't work in H17+. I understand setting viscosity by attribute, but it appears FLIP particles don't have an age attribute, so I'm not sure how to shoehorn one in there.

 

Thanks!

[DonRomano]

Hey, just use a geometry vop, bind the viscosity and multiply it with the age, and then export the viscosity. You can add another multiply with a constant to tweak values and get the result you want ! And don't forget to plug it into the particle velocity !

 

Cheers,

 

[evanrudefx]

hey,

here is a file. It shows a way to make a birth & age attribute.

hope this helps------

flip_age.hipnc

[bentway23]

Thanks, gents!

 

Evan, your example was great. I replaced with viscosity wrangle with a simple f@velocity = @age * [a number] and it did just what I wanted.

Don, I missed something on yours, but I can tell the error is mine. I've got screenshots of the node trees. I can tell the Geometry VOP is added in correctly--if I crank up the offset value (the parameter I added going into the add) it does alter the viscosity--but trying to multiply the age * the bound viscosity * a parameter multiplier isn't doing anything. What did I miswire?

fliptest.hip

[bentway23]

Also, someone on the SideFX forums pointed out that you can add an age attribute right there on the FLIP solver. Hidden in plain sight.

[Sepu]

[bentway23]

Yup, someone pointed that out on the SideFX forum. Beautiful, and big and obvious and staring me in the face the whole time. Thanks!