Change emitted particle size over time (for mograph)?

Hi folks,

I’m messing around with the idea of using particles for motion graphics. As a way to create geometry by moving an object through space.

Could anyone tell me?: Is there a way to change the size of the particles that are emitted over time? So, for example, they start small, and stay small, and gradually get bigger. So just to be clear, once a particle is emitted, it should never change size.

Please take a look at the video below. What i’d like would be for the emitted spheres to start on the left very small, and gradually get bigger as the emitter moves to the right of the screen. So the final shape that gets drawn out is a cone.

I tried to achieve this using a texture gradient controlling the particles, and this sort of works, but not really, because the size of each particles still changes over time. Maybe there’s a setting that would fix that, but i can’t find it.

What would be even cooler would be if you could change the size of particles with a lattice. If that’s possible, id love to know how. I tried it and a lattice will effect the position of a particle, but not it’s size.

I’ve also attached the blend file in case anyone is interested in taking a look.

Many thanks!

particles mograph.blend (2.0 MB)

Take a look here, you can control size with a texture

Thanks, i already got a texture to control particle size, but it’s doing it over the lifetime of each particle.

What i want is, for example, at frame one, to be emitting small particles, which stay small, and over time, larger and larger particles get emitted, none of which ever change size after emission!

Is that possible?

Geo nodes or multiple emitters that emit different sizes.

oh, damn, i didn’t mess with geo nodes yet, have no clue how to set that up.

So geo nodes can spawn meshes over time as well? The particle system allows sub-frame emission, which is important for smooth graphics, i doubt geo nodes let’s you do that, right?

Yes you can use #frame as a driver/trigger and roll yr own,

but why dont you just use 2 or 3 emitters in the same position with different sized particles and offset each one?

or looking at your anim, 200-300 emitters.

That would be crazy complicated to set up and impossible to edit! … or perhaps i’m misunderstanding you! (718.5 KB)

file for you.

Thanks man!

I tried it but nothing happens when i hit play! … maybe there’s an addon i need to activate or something?

Ive not made it play, i was leaving that to you.

type #frame into one of the value nodes, and hit play…

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I don’t understand, it already has values in the value nodes (see pic below)!

Any chance you could tweak the project so it works? Then i can reverse engineer it and at the same time make my first foray into learning Geo nodes! :pray:

Yeah, so did you type #frame into one of them?

Im hardly going to do that for you and resend the file!

#frame will create you a driver, the node will turn pink like this…


Im all for helping you, but you have to help yourself too!

Ah, i thought you meant by “#frame” that i had to type in a frame number, not that i literally had to type in “#frame”!

Like i said, i never messed with geo nodes before!

I tried it but it still doesn’t work.

Which Blender version did you use to make it?

ok, did it go pink?

then did you press play?

#frame is a driver thing not a geonode thing, it works almost anywhere in blender where you want to drive something by the timeline.

Thanks, yes, it turned pink, but nothing happens … I’m learning GN now so i’ll come back to this in a few days when i have more understanding and can work out what’s going on …

Hi, Try downloading blender 3.0 , It should work there.

@ digitvisions, great, that fixes it!

@ AlphaChannel … thanks man, appreciate it!

@ Anybody: one thing: anybody know why the background stays grey chequered, even in rendered view? … even though the world has a black material applied to it?

Hi, check that transparent is not selected in the render properties.