Attach particles to surface

[irongraft]

Hi guys,

I've emitted particles from two spheres, which are initially overlapped since I want them to emulate a cell division. Attached three frames.

As you can see, at frame 981, that is when one of the two spheres is moving away from the mother cell, the particles surrounding it move slower than the sphere itself, then for a few frames, I see a piece of surface without particles on it. In other words, particles follow the attached surface, but move slower.

How can I make particles be more tightly bound to the relative sphere?

thanks in advance

[irongraft]

Any help?

[slimboJoe]

Not enough info to help.

That looks cool, though.  Did you figure it out? 

[irongraft]

not yet, sigh. Working on it.

Will update the forum if and when done.

thanks

[slimboJoe]

I'm in Particle mode right now.  Maybe I can help.

How are you attaching them to the surface of each sphere?

[irongraft]

OK cool.

I've followed this old tutorial: https://www.youtube.com/watch?v=04lB-FISp7E

Actually, two spheres that are combined, made two clusters, ensured that UVs do not overlap.

Then, I've emitted particles from the combined spheres, used these expressions at creation:

goalU = parentU;
goalV = parentV;

goalPP =1;

and I've "goaled" particles to spheres.

Finally, I've added a jiggle deformer to the spheres (when spheres stop).

That's all, in summary and here you can find my scene: https://www.dropbox.com/s/f6010ayo1x6mgz6/intro_two_spheres.shaded.0002.mb?dl=0

thanks in advance, please let me know

[irongraft]

this is a quick update.

My advance on this topic was that of caching particle (ncache) and raising "conserve" parameter to 0.8.

This seems to have helped as from the attached still. The penetration of the emitting geometry is reduced, although still there.

I'd like to add that, this happens only if I batch render a time slice, e.g., from 975-990, and do not happen if I render only and directly the still 978. In this case the particles follow well the geometry.

This makes me think that the problem might be the fact that particles look like "idle" and not immediately responsive.

thanks for any reply

[irongraft · Accepted solution]

Hi Guys,

finally it looks like I made it.

After a long trip, I've learned that when particles are attached to surfaces that move very quickly, you must increase the over samples (FX combo box. nCache > Edit Oversampling or Cache settings). It suffices for me to increase to 2.

In addition, under the "Solver attributes" of the nucleus node, I've set the Timing Output to "Subframe". (not sure if this was essential)

Under the Dynamic Propeerties of the particle node, I've lowered the "concerve" attribute to 0 (maybe boring, but it was necessary).

That's all