Scatter points uniformly by density

[nomojosh]

I'm wanting to use density to scatter some points along the centre of some geometry

I've looked at Iso offset and some volume ramps, but the scatter still seems to have some jitter? I want them to be perfectly centred along the object; each at the furthest point from the surface. 
How can I tell scatter to explicitly place points at, for example, density 1.0 and no less?

Thanks
 

[Atom]

Don't use scatter, draw a line through your mesh and use a Resample node on the line to establish the point count you require. You could also try a pointsfromvolume node in place of a scatter node to evenly distribute points within a mesh.

Edited July 14, 2022 by Atom

[nomojosh]

1 hour ago, Atom said:

Don't use scatter, draw a line through your mesh and use a Resample node on the line to establish the point count you require. You could also try a pointsfromvolume node in place of a scatter node to evenly distribute points within a mesh.

Thanks Atom, the points from volume almost worked, but I'm still getting a lot of variance. 

In my head I'm sure I could draw a line of points by using SDF/density data but I"m struggling to put it into practice.


 

[animatrix]

What you are looking for is the straight skeleton / medial axis. It's hard to do it on arbitrary geometry but if your geometry has consistent topology, you can use some of these ideas:

 

Edited July 14, 2022 by animatrix

[ryew]

Tim's video above is bound to be a cleaner (more procedural) solution, but here's a modified file with a line in the center that works because of the way the rope is modeled (i.e. poly tube with cross-sections spaced out); note it does not work for the loop at the end, but you'll probably want the loop and knot attached at the end of the sim for the additional weight that would be there pulling the rope down  in reality (as well as to preserve the volume)

Rope_wire_deform_mod.hipnc

Edited July 14, 2022 by ryew

[nomojosh]

7 minutes ago, ryew said:

Tim's video above is likely a cleaner (more procedural) solution, but here's a modified file with a line in the center that works because of the way the rope is modeled (i.e. poly tube with cross-sections spaced out); note it does not work for the loop at the end, but you'll probably want the loop and knot attached at the end of the sim for the additional weight that would be there pulling the rope down  in reality (as well as to preserve the volume)

Rope_wire_deform_mod.hipnc

Wow thank you, the fuse really nailed what I was after. I was also exploring carve but extract centroid does a much better job.

Also, thanks animatrix, I'll explore that too. Again, the fuse is an important step there.
 

[Benyee]

try this trick if you want to avoid resorting pts after getting them

get_pts_at_geo_centers_od.hip 

[Aizatulin]

The labs 3d straight skeleton is also a powerful node, which may help here.

scatter_around_skeleton.hipnc