Fade Particles in Pflow regardless of age.

[twetzel2k]

I know how to fade particles based on age.  (delete by particle age and a Dynamic Material with Particle Age in Opacity)

However, I need to be able to fade particles all at the same time, regardless of age.

Example:  I have spawned particles by Travel Distance (so newer particles are younger) but at a specific time, I want to fade all the particles away at the same time.    

I have tried an Age Test (A

[irishman_team_kilber]

have you added a birth rate? this is where you can add a start time and a end time at the end time the Particles will fade out!

[twetzel2k]

Yes, as far as I know, you can't have particles without a Birth.

Diagram of my flow.

Birth (0-30)

...

Spawn by Travel Distance

out to...

Display

Delete by Particle Age 30    (this fades the first particles and gradually the rest.)

.

What I want to do is be able to FADE all the particles at the same time, no matter what their age is.

[irishman_team_kilber]

due to i have basic knowledge of the particle flow source i cannot really help anymore from what i found if you don't have one then you need to add a delete operator, most of my infomation came from Lynda.com and the Particle Effects video tutorial and deconstructing the elements by Pete Draper.

https://forums.autodesk.com/t5/3ds-max-forum/particle-fade-out/td-p/4282858

I hope you get this sorted

[Alfred.DeFlaminis]

Hello @twetzel2k,

There are a couple ways you could handle it.  

1) The easiest is to run the Pflow system through the mesher and animate visibility or the opacity on the material.  Not elegant, but simple.

2) The next easiest way is to use a Material Static and then animate the opacity on that material.  Since it's static, it'll affect them all at the same time.  File attached.  

There are probably more ways, but these two were the easiest to me.  Please let me know if you have any questions.

Best Regards,

[Alfred.DeFlaminis]

Hello @twetzel2k,

I just wanted to follow up here, any thoughts on my previous post? Thanks for the update!

Best Regards,

[twetzel2k]

That method works but was hoping for a bit more control.    It may help to understand what I am doing.

Say an explosion goes off.  I have the main explosion force but also the pieces that burst out trailing smoke.  A wind comes along and fades it all away.  

The main explosion is not a problem.  its the trails created with Spawn by Travel age.  I can't get rid of those by particle age because they are all different ages... some just born, others around a while.

If I do the material static method above that you mentioned, it works, but very uniform.  The wind would blow it all away, but there would be some variation.  The problem is that variation would not be based on particle age.

Maybe one option would be 4-6 Send Out tests to 4-6 Static materials that are animated different times.  That seems clunky though.  Surely there is a more elegant way?

[Alfred.DeFlaminis]

Hello @twetzel2k,

When the explosion happens you could send those particles to a new event and set the fading to event age/duration rather than particle age with the dynamic material. If you have some particles that should stay around longer than the standard fading particles, send just those out to a 2nd event with a longer or null fade time.  (Or, am I misunderstanding?)  I think the tricky part with your current setup is using particle age rather than event age.  

Or, maybe you could send particles in a loop between two events with an age test which would also fade them out slowly as some particles passed the test and get sent out, while others don't and get faded.  (In a general sense.)  Might be worth a shot.  (But might require particle age over event page for these to avoid popping... I'm not sure if the opacity will follow from event to event.)  

If I'm still not quite getting it, would it be possible to share this file with me? If privacy is necessary due to NDA reasons, I can create a private folder for you. 

Best Regards,

[twetzel2k]

I have attached the file.   It is a simple explosion and gets my point across.   

Inside, the explosion goes off and burning particles fly out.  I would like all the particles to fade between 30 and 45.   but if you watch the file, the burning trails fade in the order they were born. 

Thanks!

[twetzel2k]

I have attached an explosion particle system.  The trails are spawned particles mimicking burning debris.  I would like the particles to all fade between frames 30 and 45.  As I have tried so far, they fade, but do it by their age (event or particle).  

See attached. 

[twetzel2k]

sorry for double post... I tried to edit / delete but I can't find how.

[Alfred.DeFlaminis · Accepted solution]

Thanks for attaching that @twetzel2k, it helps. 

The easiest way to do this with your current setup is to set your opacity value to 0 and then animate the % of opacity over frames 30-45.  I have a screenshot below to show what I mean.  You can basically leave everything else as is.  I also included an updated file.  Please let me know if you have any questions.

EDIT: I realized I didn't explain *why* this works, so I felt I should do so here.  The opacity box labeled "Set to 0" above does nothing initially because you have a map slotted in the opacity slot.  If there was no map there, the object would have full opacity.  The "100" number next to the map slot that I labeled with "Animate going from 100 to 0 from frames 30 - 45" is a spinner that blends between the set value of your opacity and the map you have in the opacity slot.  So animating that from 100 - 0 blends between your opacity map and the opacity value, which is 0.  The practical upshot is that it acts as an overall opacity control.  

Best Regards,

[twetzel2k]

Thanks for that.   I knew about the map % but didn't think to combine that with particle age.  Good idea.

Unfortunately it is still fairly uniform.  I am working on a mask on the opacity channel that instead of using the 100-0 value, it will go from black to white.  I am trying an animated texture map with noise.  Trying to get all the particles to disappear together but with +/- 5 frame variation.

[twetzel2k]

it worked!  Take a look if you are interested.

[Alfred.DeFlaminis]

Hello @twetzel2k,

That looks great!  For some reason I thought you wanted a uniform fade out, so that's my bad.  Mind listing your steps so one of us can mark the solution for the next person with this problem?  Thanks for that!

Best Regards,

[twetzel2k · Accepted solution]

Sure!  

1.  Create an animated sequence in After Effects:   A solid layer with a noise effect on it.  I then faded it from complete white to complete black using the noise.

2.  Apply that image sequence to the Mask of the opacity channel.  Set the Start time to when you want the fade to begin.  Set the Looping to HOLD. 

3.  Every thing else is the same for the particles.

[Alfred.DeFlaminis]

Hello @twetzel2k,

Thanks for posting that!  Always nice to have the solutions in these threads for other users, I appreciate that you took the time to post.  Kudos!

Best Regards,