3dome

happy to help not in front of Houdini right now, but if you don't want to have them stack up you could either just use a point relax SOP (maybe only on the blue points) or not blend all the way to 1 (-> percentcomplete) but stop a bit earlier, randomized per point Depending on how detailed you need to go, you could factor in pscale (if present) but sooner or later things will break and you'd be better of using a solver

i would assume this is a more efficient - and I would say simpler - way: if(@Cd.x < .5) //do the operations only on the blue points { int near = nearpoint(0, "\x40Cd.x>.9", @P); //find the nearest neighbour but already limit the points to sample to the red ones vector p = point(0, "P", near); @P = lerp(@P, p, ch("percentcomplete")); } for a bit more "organic" movement you could do something like this: if(@Cd.x < .5) { int near = nearpoint(0, "\x40Cd.x>.9", @P); vector p = point(0, "P", near); float b = fit(@Frame, 1, distance(@P, p)*125, 0, 1); @P = lerp(@P, p, b); //blend the positions over a certain amount of time based on the distance between the blue and red point, so distant points take longer to complete the lerp() }

Use this expression: nprimsgroup(opinputpath(".",0), "groupname")==0 If you are looking for a point group, use npointsgroup() instead.

of course it removes them, because they are volume related intrinsic attributes. But if you see them, there's no need to convert to polys anyway. Just use them in your shader

can't upload files and i usually work straight with VDBs but let's assume 1) you have a sphere -> isooffset Do you see the measured* intrinsics? (in H16.5 they are available) 2) convertvdb (to VDB, class Fog to SDF) 3) convertvdb (to Polygons) 4) from there all the measure and sum stuff (measure + attribpromote SOP) will check this evening if I can see intrinsics after 1) in H17

don't have H17 at hand but since volumeRasterizeAttribute uses volumeRasterizeParticles internally and at least in H16.5 volumeRasterizeParticles has those intrinsics I don't know why they shouldn't be available to you. I don't think SideFX removed them in 17, need to check later though edit: in any case, this is Houdini so there's a million way to do things. How about convert your volume (to SDF) to polygons, measure area, sum up area -> get some value that way

It doesn't create the attribute by default, but what stops you from doing it yourself? Also you might leverage the intrinsic attributes measuredvolume and measuredarea

no i don't think so but you can use this bbox("../foreach_begin1/", D_ZSIZE)*detail("../foreach_count1/","iteration",0) to get rid of the hard coded value and stay fully procedural

have this expression on your first keyframe: bezier()*if(detail("../foreach_count1/","iteration",0)%2==0,1,-1) (just add the bold part)

not sure if i understood correctly, but I'd try a switch SOP with an expression like sizeOfVolume < threshold to switch between 2 material SOPs edit: or store the size of the volume in attribute that you read (bind) inside of the material followed by two-way switch, etc to drive whatever material parameters you want to drive based on that

assemble (pack) them, use Add SOP to keep only the points -> basically ready for second copy stamping

apart from TOPs you can always use Fetch ROPs and wire them together in the desired fashion edit: also have a look at this

as a start turn off any disturbance, turbulence, shredding, sharpening, confinement, play with Temperature diffusion, maybe add a gasblur if you are still unhappy use that as a base and shape the sim from there

in a wrangle, plug in the points you want to make "collide" in the first input, SDF in the second (i recommend turning on "Fill Interior") float depth = volumesample(1, 0, @P); //how deep inside the volume is the point vector grad = volumegradient(1, 0, @P); //direction to the surface of the volume (depth = 0) at the point's position @P += -depth * grad; //to push the point to the surface of the volume, you need to invert either the depth or the gradient

maybe this can help