Hi all

Here are basic functionalities of the particle fluids.
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Blender Particle Fluids integrate into the existent powerful Blender particle system a fluid simulation tool that allows a wide range of fluids types, from steam to water to goo, slime and giggly fluids.
The particle fluids inherit all the goodies of the base particle system, like baked simulations, scripting, etc.
In future releases it will also include meshing particles .
Blender Fluid Particles uses a boundless interpolation technique to sample the fluids body called SPH (Smoothed Particle Hydrodynamics)
Each particle can carry any fluid property: density, pressure, temperature, color, etc.

Smoothing radius is the most important parameter in the simulator, it controls the influence of each particle, and determines the performance and the type of the simulated fluid: for small fluid scales (droplets, tiny water) use a relatively big smoothing radius (1.0) and for big scales fluids (sand, sea, rivers) use a small one (0.2-0.1).

Mass controls the amount of fluid matter that each particle represents, it is important for multifluid interactions (denser and lighter fluids) and also for simulating different fluid scale with the same particle amount.

Viscosity controls the movement of the fluid, making it  more goo like and also more stable: it is a factor that dampens the relative velocity of each particle.

Particle damping is a stabilization factor and controsl the absolute particle velocity: when a simulation seems to be out of control try to increase it or play with viscosity. It differs from viscosity because the second damps the relative particle speed.

Stiffness controls the surface tension on an external level, but internally is an attraction force in each particle smoothing radius. For small scale fluids use high stiffness values (1.0) and for large scale fluids use low to none ones.

Repulsion factor has the opposite effect as stiffness factor, it repels each particle from its neighbours to maintain an Equilibrium.

Collider damping affects the bouncing of the particle in the collision event, the more collider damping the more energy the particle will loose the particle and consequently possibly get stick to the collider surface (not enough remaining energy to cancel the attraction force).

Collider particle friction affects the particle velocity as it travels over the collision object, increase its value to get realistic slipping liquid effects.

Rest density is an important parameter that sets the density at which particles will try to maintain under a zero force field or rest state. Visually it controls the relative distances where particles will be settled.

Tweak parameter is a time step tweak for the simulation, if a sim set up goes unstable first try to lower the time step by setting a fractional tweak. SPH simulators are not unconditionally stable: they are stable only for relative small time steps, that’s the reason why increasing the particle count without adjusting the rest of the parameters could lead to exploding simulations The good news is that always will be a set of parameters that will make a desired simulation stable.
The particle integrator is the function that actually advances particles over time, they feature more fast and stable simulation, so correctly choosing the appropriate integrator is crucial. In general Midpoint is the most stable while Euler is the fastest and Verlet is more suited for fluid behaviors.

For Goo like fluids Spring is very important, this is a force among pairs of particles that try to maintain them to a fixed distance, the rest length.

The rest length is the distance particles will try to maintain with a force proportional to the spring factor.

Brownian adds a random movement to the particles, useful for small scale fluids or crazy FX’s.

Collider stickiness controls the force factor that try to stick particles to the collider surface, this is great for slipping fluids.
Square viscosity is a second order viscosity factor, used for advanced fluid for enhancing viscous behaviour.

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Particles fluids can be currently rendered as billboards, simple dots, halos, instanced objects and volumetric distorted spheres in the pointdensity texture type.

In the future they can be rendered as fluid isosurfaces.

There’re plenty of ways in particle fluids for interactions and advanced setups, and combinations of the parameters lead to non-linear behaviours so they are not the simply sum of
effects. If you want to master particle fluids a good amount of experimentation is advised as well as a basic understanding of particle fluids theory.

Here you could download this post as a pptx:
Blender Particle Fluids

Cheers

Farsthary

In this quick Blender 2.5 video tip tutorial we demonstrate how to use multiple background images. This feature is very useful and allows for layering images in the viewport and assigning separate images to specific viewing angles. Without the need for multiple viewports.

Cast: Wes Burke, Jonathan Williamson

In this tutorial, I go over techniques for creating hair, and giving them textures and materials. The first is Mesh hair using Bezier Curves, and the second is Particle Hair.

Cast: Wes Burke

Okay okay, should’ve probably updated you on this stuff earlier.

The first minute has gone through some radical changes since the last time I posted about it, and I think it’s much improved!

To bring you up to speed, the first thing I did was try an alternate ending for the bandit fight, partially based on the comments I received on the blog. I restructured things a bit to give it more of a frantic quality, and to better introduce the Shaman character. I can upload this version if you’re interested.

But a few weeks ago we decided replace the scene with another section of the fight scene that was originally placed later in the film. I think this change really streamlined the film and made it feel much more cohesive. An unavoidable biproduct of this choice is that we’ve completely scrapped three of the four guardian characters. (!)

Anyway, check out the current version of the first scene! Except for the last few shots, which are still in layout, the entire scene has been brought to *final* animation by Lee Salvemini. I could also show the layout version of the whole scene if you’re interested.

Jan Morgenstern is also doing great stuff on the sound for this scene as well! Dialogue edit and mix are perhaps not 100% final, but it’s getting close. See if you can spot the cameo in the soundscape!

Next time: renders!

–Colin

I've spent a lot of time over the past couple weeks looking over the film in it's entirety, and it's been a reassuring experience. I significantly tweaked the edits of about a half-dozen scenes, eliminating unnecessary lines that just kinda bogged everything down, but that I'd been too close to the film to trim out when I did the initial edit over two years ago. A couple of these changes may be reversed after the producer review... but regardless, it feels good to have chopped off some of that fat.

"Fat trimming" aside, it looks like the film is still clocking in at over a hundred minutes, which is a nice meaty number. I mean, we don't want the film to feel overly long (which, fortunately, hasn't been the response from anyone yet), but it's fun to be able to give someone an entertaining experience of significant length.

While we're waiting for final picture lock, and for sound design to ramp up, I've been able to start appeasing the perfectionist in me and have been going back and updating old shots that never really were as well done as I felt they could have been. Often, in the creation of shots, there comes a point when I have to ask, "Will anyone even notice that, if they're just watching the film?" and if the answer's "probably not" I frequently just let it be. It's a surprisingly easy bar to establish (although I know for a fact I've been the cause of frustration for other, more perfection-minded members of the VFX team).

I admit, there are times (many times) when I watch the film and kick myself. I look at scenes we shot and think, "Why did I direct it like that!?" or "Why didn't I get an angle from there?", but whether or not those questions have valid answers (and very frequently they do, given our schedule limitations back during the shoot), I'm still surprised by the energy and the just overall good-timeness of the final edit. My great thanks to all of you who have helped us get this far. I can't wait to show you what we've created!

Ian Hubert
Writer Director

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Hi all

Thanks to Jahka review and advices I have corrected the particle fluids patch and have simplified it for better integration. Also I have discovered and solved an important bug in the multi-fluids interaction that caused strange behaviors in fluids.

here you will find the new patch:

http://www.pasteall.org/11805/diff

and here a new test blend:

http://www.pasteall.org/blend/2223

The short list of changes are:

- Important multifluids bugfix.

- Better defaults and parameter naming.

Cleaner patch.

I have temporarily removed the particle color and temperature visualization since they are targeted for future design in Jahka framework, but once committed the code will be easy to add back.

I will soon upload a pdf with all the features of particle fluids.

This exclusive Video Blender tutorial will cover the entire of process of modeling the mechanic character based off of the concept art by Drew Wolf. In this tutorial you will see the entire modeling process demonstrated, everything from blocking-in to fine detail work. You will find many techniques throughout that you may apply to your [...]

http://blendercookie.com

Updating the blog has become somewhat a burden… doing a good post can take many hours, and “just dump stuff on the blog” is a bit scary! Nevertheless, here I do an attempt to just dump stuff from our “weekly” folders. Just WIP. No further comments… but I like it!

-Ton-

Just a quick update:

Development of the DVD is moving along at an increasing rate as Blender 2.5 continues to become more stable. Here's an abbreviated version of the mindmap depicting the current state of how the DVD is being organized.

Click to enlarge image.

A special Thank You to all of the pre-orders that are making this project possible!

UPDATE
Question: Can you post a little bit about what kind of videos you are thinking about for the "Technical Reference" section?

The Technical Reference section will contain many very short (less than 2 minutes) videos covering very specific technical subjects such as targeting a camera, snapping, local view, setting up a render layer, etc. Think of it as a video wiki for the DVD's contents.

I believe it will make learning more efficient because you won't have to waste time scrubbing through a video for that one part that shows, for example, setting up a render layer.

I'll create reference videos for things that aren't repeated too often in the project videos. For example, there won't be a reference video for "pressing the E-key to extrude".

Two things will determine how much content is in the Tech Ref section: time and disc space. To deal with the time issue I'll record these videos near the end of development to get a better feel for what may be helpful as a Tech Ref video. To help address the disc space issue, I'll record these videos at a smaller resolution with a lower framerate, and maybe framed to only show what's relevant.

Question: What about the Appendixes?

The Appendixes will contain quick references for things like:

• Using experimental versions of Blender
• Upgrading Blender
• Reporting a Bug
  
• etc.

Question: What will the Index be like?

The Index will be similar to the index of a printed book or the Lables listed on the right side of this site. I'll be "tagging" videos as I create them, and these tags will allow you to click a link on the Index page and get an appropriate listing of videos. Honestly, this is just something that I HOPE to be able to do. Currently, I'm not exactly sure how to set this up for the DVD's html interface, but I will at least have everything tagged so it will just be a matter of researching how to implement something like this. I'm sure it's not an original idea so the question has been asked and answered somewhere online.

technorati tags: Blender3D, 3D, graphics, Blender tutorials

In this Blender 2.5 Video tutorial, I go over techniques for creating hair, and giving them textures and materials. The first is Mesh hair using Bezier Curves, and the second is Particle Hair. Support the site – Download includes: High resolution .mov Video .blend file at the state of the tutorial

http://blendercookie.com