Increase The Fps Simulation For Retiming"

#1

Hello everyone,
I’m trying to slow down my particle flow simulation.
This was the information I could get from the FAQ regarding time:

Parameters that measure time in Particle Flow, such as Birth Emit Start/Stop and Age Test Test Value, are specified in frames. However, Particle Flow is always aware of the current system frame rate (fps), and if you change this rate, it adjusts all time-related parameters to keep the same timing. For instance, if you set Test Value to 60 when you’re using the NTSC frame rate (30 fps), and then switch to PAL (25 fps), Particle Flow automatically changes the value to 50, so the age that’s tested for is still two seconds.
On the other hand, rate parameters, such as Speed, are measured in units per second, so they don’t change when you go to a different frame rate.

I already researched how I could slow down my simulation but the solution that I could get was defining the final look of the particle behaviour in 30 FPS, then I increased to the desired FPS, in this case 240, and adapt some of the parameters that don’t change. This process takes a lot of time so I was trying to speed things a little bit.
Is there a way to store the data in cache like fumefx and then do a retiming?
I’m checking these two links now, one that uses the PRT Loader for retiming and the other that talks about bullet time - http://www.thinkboxsoftware.com/krak-retiming-part-anim-prtldr/
http://www.orbaz.com/forum/viewtopic.php?t=175

Just wanted to know the opinion of the community about this.
Thanks.
Cheers

#2

did you try pflow baker? you can then re-time the animation.

or a compound mesher with a point cache on top. Which then you can also re-time.

#3

I’ll check those solutions thank you.
Deko in his website has all the links organized:
http://www.deko.lt/lab/particle-flow-tipstricks/
Here is the link of Bobo scipt - http://forums.cgsociety.org/showthread.php?t=652477
Pflow baker -

NOTE: This script bakes only the viewport particles, so in order to get the amout of particles set in your system, set the viewport count to 100%
To me this isn’t a very useful solution cause I’m using a lot of particles.

My main objective is to send this information to krakatoa after.
I’ll send some feedback of what I find… If anyone ever tried to cache for retiming please give me your point of view.
Cheers

#4

if you have krakatoa then why not save the particles to prt.

load them up in prtloader and try using the loaders retime function.

pflow baker will work with shapes/geo but if all you need are particle positions prt is the man.

#5

I’ll do that.
thanks Nickolay

#6

Hey Vitor, have you seen the Rayman Legends Making of? They use a cool technique to do somethin like this. Maybe it’s useful.

https://vimeo.com/87339489

It’s near the end of the video (around 15:00m)

#7

Are you talking about the “em-distributor”?

#8

yep. it’s a combination of pflow baker and this em-distributor.
If you think it’s useful you could contact Mhamed Elmezoued to ask him about it.

#9

I’ll send him a message.
In the meantime if I find a better solution I’ll post it here.
Cheers

#10

yeah, keep us up to date.

#11

I’ve decided to save the particles to a PRT sequence including the position, velocity, orientation, scale, id (for interpolate sub-frames) and the color channels ( wanted to maintain the colors of the pflow). I loaded the sequence with a PRT Loader and increased the number of frames with Graph and Interpolate Sub-frames on. the speed of the particles reduced a lot so it’s becoming very difficult to add motion blur to the simulation.

I have two questions if someone can help me here:

1 - how can I maintain the speed of the particles even after the retiming for motion blur purposes?

2 - what’s the best way? creating the several partitions after or before the retiming with graph? (of course creating them after will increase a lot the data that I have to store in disk)

Hope we can start a interesting conversation regarding this theme here.
Cheers

#12

Hey Vitor, i’m not really into krakatoa so i’m not answering your last question.
Even though i found out that Clovis Gay have a script called replacer that you can use with pflow baker retime your particles.

http://www.kinematiclab.com/#!replacer/ctj1

#13

Thanks alvaro.
Regarding the first question nickolay411told me this

use a magma flow modifier over your prt loader. input your velocity channel and multiply it by 10 or 100 then output the velocity.

Getting good results