Verlet Integrator

Hi all 🙂

Currently the particle system support 3 integrators types (in english integrators are what actually advance particles in time)
and for many users that´s the kind of options that fall under the I-always-will-use-the-default-value category,
and while for many set ups different integrators provide very similar results, in others they could make the difference.

The simplest integrator, Euler, is very fast but not very accurate, internally Blender performs only one cycle of some calculations.

The second integrator, Midpoint , is sligthly slower because it performs 2 cycles but is more accurate than Euler and is the default integrator.

And the third , RK4 (Runge-Kutta) , as you may guess is the slowest and more accurate of them, and performs 4 cycles of calculations in Blender

The good news here is that I have found another integrator type that is as fast as the Euler integrator (the fastest) since it requires only one cycle of calculations and is more accurate than the Midpoint even, the error is of fourth order: The Verlet integrator  http://en.wikipedia.org/wiki/Verlet_integration#Basic_Verlet
have several advantages over the others and is very stable and fast, and gives realistic results.
with many particles interacting each others the Verlet integrator clearly shows the speed boost even over the Euler integrator.

the hand made patch is at http://www.pasteall.org/9364/diff

I have implemented it in Blender seamlessly and I suggest it as the default integrator, the previous integrators suffer from an increase of energy in time, note how the amplitude of each bounce is biger than the others in the previos integrators while in the Verlet is uniform as should behave in a conservative enviroment (no friction,damping,etc).

It is very easy to implement in Blender and is a small step toward improvement, hope you like it
Cheers Farsthary

Verlet Integrator

Cool effects

Hi all 🙂

Since SPH particles are , well, just particles, they can seemlessly be integrated with the whole dynamic system, providing an incredible range of particle FX’s, here for example I show you some simple yet beautiful cases:

the previous videos show SPH particles rendered with pointdensity textures (volumetrics)

And this one shows an interesting effect with instanced particles and some force fields with no gravity

Hope you like them
Cheers Farsthary 🙂

Cool effects

A sudden Hurricane and a talk about the weather

hurricane

Wow!

I was happy that this season we didn’t have any hurricane over Cuba, but I guess this was too much to ask 🙂
This weekend we had a little hurricane: IDA, that reached the 2nd category (2 of 5)
nothing compared to last year season where we had 3 hurricanes of the 4th and 5th category that put on the knees my already devastated country. And as a curiosity IDA has become an extratropical hurricane, an invernal one.
Nothing really happens this time, I was just locked in my home the whole weekend, and luckily without electricity blackouts so I could continue my projects 🙂

A sudden Hurricane and a talk about the weather

The right move

Hi all 🙂

2

An open source developer should not have any problem in dropping a project for joining another if the second one promises better features, as working in two seperate projects will only make things more difficult and slow and at the end necessarily one of the two solutions has to be dropped. The good thing about being open source is that this is not a race among devs, this is a collaborative work 🙂
So I didn’t have to think twice to make the switch once I had contacted Stephen and reviewed his implementation of Particle Based viscoelastic fluid simulation (that is also an SPH method) based on several reasons:

It’s much more stable
It’s more artist friendly
It avoids duplicate efforts
It speeds up the development

This is not the first time something similar happens to me :), the first was Volumetrics, then Photon mapping (which is currently on hold until some physically correct material system gets added or some future decisions are being made) and now SPH particles so I have experienced that 😉

We are currently working togeither (also with the help of Jahka) to deliver very soon a testing build.

Cheers Farsthary

The right move

New Blog!

Hi, this is -again- a friend of Farsthary! 🙂

As Farsthary made last week a “little” excursion in the beautiful particle world of Lord Jahka (sorry if this sounds cheesy…), I thought you would be interested by some pieces of information:

– Jahka has kindly accepted to review his patch, so stay tuned to Jahka’s blog 🙂

– Stephen Whitehorn aka chickencoop (an early supporter of Farsthary) recently started his blog about other amazing particle VFXs! Kudos to him, we wish him a lot of success!

All progresses relative to the particles system are managed by Jahka, who directly adds them to the trunk. This means that if Jahka speaks about it on his blog, you can find the new tools a few days later in the fresh 2.5 builds from Graphicall (thank again to them).

Regards

p.s: sorry about the troubles with the new wordpress layout (problem under firefox for the comments, strange formating..), but this is one of the rare thing that Farsthary directly manages, so I don’t want to “steal” that to him by doing it without his authorization… so please wait a few days so that he corrects this himself..  Currently, if you want to let or read  a comment, you have to go to the previous post, then click “next”..

New Blog!