delete by expression

[quarel]

Hi guys.

I have a structure created from metaballs. But I need to delete procedurally not conected metaballs from this. is it somehow possible?

I also attached hip. file

thanx

grid_meta.hipnc

[anim]

not connected to what?

if you want to keep only the the largest connected piece of geometry, here is the solution

grid_meta_keep_largest.hipnc

[anim]

and here is an example if you want to delete pieces which are made only from single metaball(may be deformed but not connected to other)

with a little note inside

please look at this file even if above example was what you need since this file contains some optimizations to your setup

je to vsetko po anglicky, ale ak by si mal s niecim problem mozeme pokecat aj sukromne, zatial sa maj

grid_meta_delete_alone.hipnc

[quarel]

wow great Tomáš! both solutions are proffesional!

not connected to what?

not connected at least with one other metaball.

this file contains some optimizations to your setup

this optimalizations are really great! I have more huge area converted to metaballs so this surely can help me!

thankyou very much.

viac napisem sukromne.

Edited May 2, 2011 by quarel

[sparkChan]

and here is an example if you want to delete pieces which are made only from single metaball(may be deformed but not connected to other)

with a little note inside

please look at this file even if above example was what you need since this file contains some optimizations to your setup

je to vsetko po anglicky, ale ak by si mal s niecim problem mozeme pokecat aj sukromne, zatial sa maj

hi, anim, it's good method. but I found your method didn't work in the houdini 10.

we can use Intersect VOP to get the right intersected primitives, but the value of "class" isn't correct when I use Primitive Attribute VOP to get the value "class".

what's wrong?

thanks.

grid_meta_delete_alone_10beta.hip

[anim]

sorry sparkChan, I don't have H10 installed at the moment

but if there is problem that Primitive Attribute VOP is not importing Primitive attribute "class" then try to promote "class" to points on metaball geometry just before vop sop

then Primitive Attribute VOP should get that attribute by weighting all points of intersected primitive and since all will have the same value you should get correct integer number

EDIT: and in VOP SOP be sure to include something like in my file for case where no intersection was found, I am assigning -1 as a class to those particles in order they not interfere with others

in your case they are getting 0 so if your metaball with class 0 is alone and at least one other cannot resolve intersection and returns also 0 then your alone metaball will not get deleted

but if you make sure that all points find intersection then its ok

Edited May 2, 2011 by anim