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View Full Version : Anyone figured out how to vary particle size against particle age?



dmack
10-08-2008, 05:23 AM
Hi I'm triny go to get particle fx to increase the size of the particle based on their age, so I can have HD Instance instances grow with particle age. Anyone managed to do that?

If not, then I vote for 'particle age' being added to the gradient options against all the particle parameters (size, weight, resistance etc). Would be great to have this as a nodal thing too.

SplineGod
10-08-2008, 07:33 AM
What you could do is download Denis Pontonniers free DPkit and
Node Texture here http://pagesperso-orange.fr/dpont/plugins/nodes/Additionnal_Nodes_2.html

In the particle tab next to the particle size parameter click on the T button and apply a procedural called Node texture. This will give you nodal access. Apply the Particle info node. One of the outputs is particle age.

dmack
10-08-2008, 08:25 AM
WOW! Man, you are good! I shall try that. Sounds like a solution to me. Sounds like it should be built into lightwave too! Good to see a 64bit version too!

Thanks for the heads up!

dmack
10-08-2008, 08:26 AM
Do you know, do the DP plugins work well on network rendering?

SplineGod
10-08-2008, 09:08 AM
I dont know but you could bake out the pfx file. I agree, Denis has added tremendous functionality to LW. That node texture plugin adds nodal to pretty much any part of LW that has a T button. :)

dmack
10-08-2008, 10:01 AM
Yeah, that's a massive benefit to LW!

dmack
10-08-2008, 11:14 AM
Hmmm, so close, yet so far it seems. I've done that and it appears to increase the size of ALL of the particles based on the first paritlces age rather than applying the node on a per particle basis. I'm trying to get particles to start of really small and then increase their size as they grow older. Am I doing something wrong?

Sekhar
10-08-2008, 12:57 PM
For particle size, set texture to gradient with particle age as input (regular LW, not DP Kit).

shrox
10-08-2008, 01:23 PM
I figured it out through trial and error, but I can't remember exactly what I did. I could post the scene with just the HV setup.

I used it for this:

http://www.vimeo.com/1456340

SplineGod
10-08-2008, 05:27 PM
Its weird that HVs would have a gradient to effect particle size based on age but not the actual particles themselves.

dmack
10-09-2008, 01:27 AM
Sekhar and Shrox sorry for the confusion, I'm not talking about HV's, I'm trying to get particles to change their size based on age. I want to do this so that I can get this passed through to HD Instance so the size of the instances change based on particle's age. That might also be another barrier.....

serge
10-09-2008, 08:17 AM
... it appears to increase the size of ALL of the particles based on the first paritlces age rather than applying the node on a per particle basis...
I'm getting the same result. I think it's either a problem with nodal particle info, or the way Dpont's node editor(s) interpret nodal particle info.

As mentioned before, we can texture Hypervoxels based on particle age (non-nodal), so this means the information is available. But when I texture Hypervoxels based on particle age with Dpont's "Node Volume" (the node editor for hypervoxels), I'm getting the same 'wrong' result: all particles seem to get the particle age of the first particle (or of the frame they were 'born').

I will send Dpont a PM and ask if he can take a look.

JeffrySG
10-09-2008, 09:39 AM
Its weird that HVs would have a gradient to effect particle size based on age but not the actual particles themselves.

I was thinking the same thing... someone should submit a feature request on this.

Sekhar
10-09-2008, 01:59 PM
Sekhar and Shrox sorry for the confusion, I'm not talking about HV's, I'm trying to get particles to change their size based on age. I want to do this so that I can get this passed through to HD Instance so the size of the instances change based on particle's age. That might also be another barrier.....

Aah, my bad. If you want to change the particle size itself, why not just use the envelope option for particle size? E.g., below is an example with FX Linker, where size of the block copy depends on the particle age. Unless you want to dynamically vary the size... I don't know how HD Instance works.

dpont
10-09-2008, 02:17 PM
It seems I can get it, using texture layer of particle size,
then node texture editor and (DP Kit) Particle Info node,
Age or Relative Age, but I needed to find a balance
between Particle size basic, set it to the max value
you want, since texture value and Age are multiplier
so Age = 1 (1s) = 100% of particle size.

Denis.

serge
10-09-2008, 04:49 PM
Thanks for the reply, Denis. I got it to work, but it only seems to work if I keep the node texture editor open. When I close the node editor the 'size change' doesn't work anymore.

I tried saving a PFX with the node editor open, but that didn't work (the particles all get the maximum size).

(LW 9.3.1 win32)

serge
10-09-2008, 04:50 PM
... why not just use the envelope option for particle size? ...
That will change the size of newly emitted particles, but not the already emitted ones. So, in your example the FX-linked blocks are not based on particle age, but on particle birth. (Unless I don't understand what you mean. :))

Sekhar
10-09-2008, 07:29 PM
That will change the size of newly emitted particles, but not the already emitted ones. So, in your example the FX-linked blocks are not based on particle age, but on particle birth. (Unless I don't understand what you mean. :))

Basing size of particle birth is really equivalent to basing size on particle age. Say you want the size to increase with age, meaning older ones are bigger and newer ones smaller. If you set the size envelope so the size goes down with time, you get the older ones larger and newer ones smaller - same thing.

E.g., see below a particle emitter that has downward gravity, so you can clearly see that the older ones are at the bottom and the newer ones at the top. As you can see, the size is increasing with age.

As I said, this is not dynamic - in the sense you're taking a snapshot for FX Linker. May be this is what you're referring to?

dpont
10-10-2008, 12:45 AM
Thanks for the reply, Denis. I got it to work, but it only seems to work if I keep the node texture editor open. When I close the node editor the 'size change' doesn't work anymore.

I tried saving a PFX with the node editor open, but that didn't work (the particles all get the maximum size).
(LW 9.3.1 win32)

Tested in 9.3.1 too, all panels closed and rendered,
particles are growing in size with age here.

Denis.

dmack
10-10-2008, 01:25 AM
Sekhar - It really is different. Try and get your simulation to always have the particles small at birth and then getting larger as they live for longer. In your example, the particles are born large to start with, then the later particles to be born are smaller. I'm after the effect of bubbles coming off something. They'd always be really small on birth and then each would expand as it lived for longer.

dpont - Could you post a scene so I can see how you've got it working? That's be great.

dpont
10-10-2008, 01:50 AM
Scene,
64467

and animated result,
64468

Denis.

dmack
10-10-2008, 02:21 AM
Thanks for that Denis. I'm still struggling though. I'm not after HV sizing, just particle sizing. So, using a particle emitter (not HV emitter) and getting particle fx to output particle size based on age. I'd ideally like to see a scene where the LW shows the particle size (output particle size and show particles) increasing against the age of the particle. All the examples so far are sizing the particles in another panel (the HV panel etc).

dpont
10-10-2008, 04:03 AM
LW Particle size can be changed over time,
can't test it with HD Instance,
but I tried a (complicated) scene,
adding a NULL with Item Motion node editor,
adding a Particle Info node with indexed option,
connect the particle Position for parenting the
Null to the first particle and particle Age to
the 3 scaling components,
clone the NULL to reach the number of particles,
you should get all null animated and growing
with age, matching the particle emitter.

Denis.

dmack
10-10-2008, 07:44 AM
I'll give that a go! Hey Denis, just wanted to say a big thanks for your DP Plugins, the node texture one in particular is an awesome addition to Lightwave, opening up the power of nodes throughout Lightwave. You are a credit to the community. Thanks.

dpont
10-10-2008, 08:22 AM
Here is what I get in preview,
64473
What you see are not particle size but Item Shape
of cloned Nulls growing with particle Age.
Here is the scene with one Null setup,
64474
just clone it (121 clones), if you don't want
to loose the particle index, increase the
life of particles.
Suppose you should try to setup HD Instance
before cloning.


Denis.