Increasing Radius??? RFxKrakatoa

Krakatoa for 3ds Max
1

Before I say Hi!!!, I must say that when I hit the rendering button, I just blown away with the speed of rendering millions of particle!!!

Im looking forward to getting the commercial licence soon ^-^b Krakatoa Rocks!!!



and yes, I have a few question to ask you…w



Firstly, Im also doing Rf x Krakatoa Integration, and i have (roughly) 1.2million RFparticles.

Then when i hit render, the particles looks fine when they are little far from the camera, but near particles are looks like…dots… . . .

Is there any way to fix this problem? ,and Is there any way to increase its “radius” of the particles depending on the camera???



Secondary, this maybe the newbie question…

Simply, I’d like to increase density of exsisting RfParticles x7-10 times more. (like subframe sampling.)

Is there any chance I can select one RFbinParticles and then create partition?

Any information welcome!!



Cheers!!!



TARo

2

Before I say Hi!!!, I must say

that when I hit the rendering

button, I just blown away with

the speed of rendering

millions of particle!!!

Im looking forward to getting

the commercial licence soon

^-^b Krakatoa Rocks!!!



Hi and thanks for the feedback. Glad you find it fast, but we are not done speeding it up yet, in fact we consider it rather slow and are working on improving that. :o)





and yes, I have a few question

to ask you…w



Firstly, Im also doing Rf x

Krakatoa Integration, and i

have (roughly) 1.2million

RFparticles.

Then when i hit render, the

particles looks fine when they

are little far from the

camera, but near particles are

looks like…dots… . . .



Is there any way to fix this

problem? ,and Is there any way

to increase its “radius” of

the particles depending on the

camera???





This is, of course, a known side effect of drawing points. We have some ideas for improvements in the future, but at this point, the only ways to deal with it are to


  1. Use a lot more particles with much less density per particle so the far particles accumulate into a dense mass while the closer particles practically disappear when coming close to the camera


  2. Use Depth of Field to turn close particles into larger circles (each particles would be drawn as multiple samples in a circle). It is advisable to set an appropriate Near Clipping Range for your camera to avoid rendering huge circles for particles that have come too close.



Secondary, this maybe the
newbie question...
Simply, I'd like to increase
density of exsisting
RfParticles x7-10 times more.
(like subframe sampling.)
Is there any chance I can
select one RFbinParticles and
then create partition?
Any information welcome!!

This is tricky, but it might be solvable.
Normally, Partitioning in Krakatoa (when working directly with PFlow, Thinking Particles or Max Legacy Particles) works by changing the Random Seeds and saving the same particle system again and again. With RealFlow, you could try to do the same inside of RealFlow, but it would require a lot of time simulating the same setup multiple times.

A possible alternative could be to try and load the RealFlow particles into Particle Flow using the new Krakatoa 1.1 operators (File Birth, File Update, ID Test) as described in the tutorials we posted recently on our documentation page.

http://www.franticfilms.com/software/support/krakatoa/using_krakatoa_particle_flow_file_operators.php
http://www.franticfilms.com/software/support/krakatoa/blending_particle_file_sequences_using_krakatoa_particle_flow_operators.php

Then, you could try to add a random factor to the particle's positions to increase their count, for example if the File Update operator is set to load both positions and velocities, your particles will be fully determined in space and time. BUT, as we described in the tutorials, after the data is loaded into PFlow, we allow PFlow to perform an integration step AFTER both position and velocity have been loaded, which results in a slight offset along the velocity vector compared to the original position in the RealFlow BIN file. You could use this to your advantage by adding a strong Force or Random Speed operator ON TOP of the RealFlow velocity or, if you are not concerned about Motion Blur, completely replace the velocity of each particle with a random value (just drop a Speed Operator AFTER the Krakatoa File Update and set it to Random 3D.
As result, each particle will be loaded according to the BIN file first, then PFlow will take the random speed vector and add to the position and Krakatoa will render the OFFSET particle instead! On the following frame, the particle will be loaded on its original position according to the BIN file, but then randomly offset again and so on. Unfortunately, the Speed operator is evaluated just once on entering an event, so you would have to send out the particles on each frame to an event with the speed operator, affect them and send them back out and into the same event on the next frame.

If you run a Partitioning job affecting the Speed Operators’ Seeds, you should get randomized positions from each iteration and effectively increase the density of your particle cloud without running multiple RealFlow simulations!



I will try this out myself today and if it works as expected, will post a Tutorial to our Krakatoa Documentation page.



Hope this helps,



Borislav “Bobo” Petrov

Technical Director VFX

Frantic Films Winnipeg

3

You could also add noise (or whatever) to your PRT Loader. Makes for softer, puffier renders.




  • Chad
4

Here is an initial version of the Tutorial explaining the process. It is Work In Progress and will be updated as I go on.

http://www.franticfilms.com/software/support/krakatoa/partitioning_existing_file_sequences.php

5

Thank you so much for such a immediate responces, BoBo & Chad!!!

Especially, im impressed with the tutorials you made, Bobo!!



I see, using PFlow’s speed (3Drandom) to make particles randomise the

position, then do the partitioning… what a fab idea!!!

and again, i got blown away with your speed of writing such a intense tutorial!!



One thing i noticed was that, the image looks smilar to maya’s “multipoint” in a way, due

to the Pflow’s 3Drandomisation…

(Or perhaps,it’s because i ask you how to get the “volume”)





Perhaps Im asking too much…, but

Is that be possible to place the (partition) particles by reading the distance of 2 or more neighbor particles??

The reason behind is because i feel a little bit sad to lose the detail that RF created:_;





I will try the latter for the Radius question, and i will attach the image when it’s done^^





Cheers!!!





TARo

6

You can do that, yes, but I suspect it will be much slower than if you just added more particles to realflow.



Thinking Particles has an iterator that might be useful for this sort of thing, but we haven’t tried it yet.


  • Chad
7

Thanks Chad!!

Unfortunately we do not have either pflow boxes and thinking particle…orz, but thanks for sharing the ideas!!! iteration sounds amazing^^



We do have FumeFX, so this might be one of my luke skywaker to increase the amount of particles… (i haven’t tried yet though…)





Right now, im working on using Pflow’s “Spawn” to increase the amount of particles*



Below pic is the rough image of original image and Pf’s speed(rand3d) applied.





Cheers!!



TARo

8

Thanks Chad!!

Unfortunately we do not have

either pflow boxes and

thinking particle…orz, but

thanks for sharing the

ideas!!! iteration sounds

amazing^^



We do have FumeFX, so this

might be one of my luke

skywaker to increase the

amount of particles… (i

haven’t tried yet though…)





Right now, im working on using

Pflow’s “Spawn” to increase

the amount of particles*



Below pic is the rough image

of original image and Pf’s

speed(rand3d) applied.







I really like the use of “luke” in place of “hope” :o)



I feel that you should try reducing the density per particle. Keep in mind that the density is calculated in world space, so it depends a lot on the scale of the scene and might require you to go way down. The result will be less sharp dots and where you have a lot of particles, you will get higher density. Right now, the image with the 14M does not look much different from the 0.5M…



Also, enabling motion blur and using around 8 passes should smear the particles along their velocity vector and also make them look less intense. Finally, try adding a Krakatoa Camera modifier to your camera and adding a little bit of DOF - it will spread particles that are out of focus within a circle of confusion and give you a smoother look, as if the particles were larger to start with…



Just things to play with.


9

thanks Bobo!!!


I feel that you should try reducing the

density per particle. Keep in mind that the

density is calculated in world space, so it

depends a lot on the scale of the scene and

might require you to go way down. The result

will be less sharp dots and where you have a

lot of particles, you will get higher

density. Right now, the image with the 14M

does not look much different from the 0.5M…



Yes, you’re right^^ i tweaked the value n i got better result now!! i cant imagine Krakatoa can handles such a HUGE AMOUNT of particles!!!



Also, enabling motion blur and using around 8

passes should smear the particles along their

velocity vector and also make them look less

intense.



yes!!! my theory was if i can get good result without motion blur, i thought that i can get twice better result when i added motion blur^-^



Finally, try adding a Krakatoa Camera

modifier to your camera and adding a little

bit of DOF - it will spread particles that

are out of focus within a circle of confusion

and give you a smoother look, as if the

particles were larger to start with…



thanks for the tip!!!im working on it right now~^^ n i’ll upload the image when i’ve done^^ or i maybe need your suggestion again^^



cheers!!!



TARo