Fields decay problem

[MaverickMongoose]

Hi Dr Sassi, hope you're having a great weekend!

I've got a super simple dynamics scene where a sphere goes though a bunch of clones and pushes them appart, I now just need the material of the clones it comes in contact with (full clone not partial) to change color.

This is pretty mush the kind of thing Im trying to achieve: https://www.instagram.com/p/DFfihSotYd-/?hl=en

I tried feeding some fields through to a VERTEX COLOR TAG - a FREEZE to make it 'grow' across the full clone when in contact, but I then to fade away I thought a DECAY on top would work. But on top of the FREEZE it does nothing.

Here's my file so you can see what I mean: https://we.tl/t-BrnqIKOlRH

Without the grow it works well, but I want the grow so it engulph the full clones, so no material is half on any clone.

I find fields super confusing, never seems to be as straight forward as Id expect.

The other issue I get with this scene is that it crashes constantly, no idea why, seems so simple. Only thing I did was change the SUBSTEPS and COLLISIONS a bit for more accuracy.

Thanks again

[MaverickMongoose]

Ive also noticed some of the clones dont push away when in contact with the cylinder, any idea why that is?

[Dr. Sassi]

Hi MaverickMongoose,

Thank you very much for the file.

I would just have two child objects under the Cloner and switch those.
This can be done with the MoGraph Selection Tag.

This Tag goes then into the Plain Effector (NO PSR checked), and only Modify Clone is on.

In the Cloner, the setting is Sort.

The Clones that stay are not moved by the power in the Falloff of the Cylinder Field, as the Force of the Rigid Tag is set to 1.2 for Position and Rotation. There are two forces working against each other, and sometimes the Clone keeps its position.

Either the Falloff is set different, or you use the Push Apart more target-oriented, meaning move it around while the limit is to the same Cylinder Field.

Another past midnight file, please have a look here:
CV4_2026_drs_25_MGsc_01.c4d

Have the RS render running

My best wishes for your project

[MaverickMongoose]

Thanks for giving that a crack so late, thats a really cool method!

I've run with that but it looks kind of abrupt in the render, so i really want to add a little decay or delay.

i've managed to get it really close here: https://we.tl/t-SRPR92ZXX6

rather than fading off from the shapes falloff which looks really obvious, I really like the decay how different clones fade back to black at slightly different times in this one.

But toward the end of the animation it stops turning them white, Im guessing because those ones already turned white earlier they cant be turned white again. It seems like it should be so simple to grow on and grow off when contacted with a slight decay but i cant get the blending right.

Also the issue with some clones not being effected was because of Rigid Body Deactivation, I always forget about that, wish it wasnt on by default!

[Dr. Sassi]

Hi MaverickMongoose,

Yes, deactivation, thank you.

Thanks again for the file!
Please have a look here:
CV4_2026_drs_25_MGsc_11.c4d

The main setup to drive the Material is in the Plain Effector.
Since your request was to have the Material for a clone and not a partial clone, this works on the whole clone.

Enjoy the rest of your weekend!

[MaverickMongoose]

This work perfectly! Thanks for that. Havnt quite got my head around how its working but Ill have a deeper look, again I wouldnt have thought of this setup!

[Dr. Sassi]

Thank you very much, MaverickMongoose.

The color via Effectors (including Fields if used) provides a single individual value for a clone, hence it affects the clone completely.

I forgot to mention, check the color in the Cloner> Transform. When it comes to color, the color in that section can cause unwanted (or wanted) results. Black is typically a good starting point.

Cheers