Box3 / ADM - Total vert count for multiple referenced objects.


#1

Using a data op, I’m spawning particles onto vertices of reference geometry.

I have a ‘select object’ op pointing at multiple objects and a ‘geometry’ op setup to spit out the ‘geometry number of vertices’ parameter, but it seems to only return a vertex count for one object…not a total vert count for the multiple objects.

While this method works great to spawn particles onto a single object, I cannot figure our how to get a total vert count for the multiple objects I am referencing.

Is there any way to get a vert count (for the spawn count) and vertex positions (for particle positions) of multiple objects?

Thanks,
Bob Dyce


#2

-Bump-

Another thought / question:

The help states:
I3 Designates Objects: Adds an Integer input for specifying an object index as defined by the Select Object suboperator.

…so I would think that this would mean I could wire in an integer. ‘1’ would refer to the first object in the list - ‘2’ the second, or something like this. However this doesn’t seem to work either.

Just to put this into context, I am using box2 particles and particle skinning to create softbody dynamics. There are some workarounds with just combining all the geometry into a single edit poly - but this step removes a lot of the ability to keep things procedural and adjust positions and parameters on the fly.

Thanks!
B


#3

The issue having multiple objects, each of those objects all start their vertex count at 1 so there is no way to determine which vertex 1 you want to put particles to so it chooses the first object in the list.

The Geometry sub-op would need another input that took current I3 object vertices. This would let you could iterate through the I3 Designate Objects list. As it is the only non-destructive way that comes to mind is to use a Birth Script and iterate through an object array (which shouldn’t be too bad if you aren’t always birthing a lot of particles) or Edit Mesh/Poly Modifier Attach and include it in the select Object.


#4

Yep! What Johnny said. The sup ob vertex position only has one integer input and that’s the vertex index id, it should have an OBJECT index id input too! Would be nice for sure.

Another way you can do it:

Make a second pflow system with a birth group. Add all your objects into the birth group.

Use a compound mesher on the birth group system, in your original system reference the mesher object , it will then loop through all the verts you want as one object. :slight_smile:


#5

Just For kicks, finding the total vertex count of a bunch of objects is still possible.

Birth Group and select all your objects.

Data op–> input standard --> shape–> number of vertices–>function subop–> sum of all particles.

That will get you the total vert count of the objects.


#6

Thanks for the responses guys! I think I’ll give the mesher solution a shot.