New child particle options video

Here's the promised demo of the new child particle options for hair. I committed these goodies already a week ago, so just get a fresh build to play with these options!

Something old something new

There have been three bigger updates to particles stuff during the last couple of weeks. Mostly things are just like they have been in the past, but only better!

1. The point cache code has gone through some major changes internally and during the recode I added compression support for all disk caches. So now you can enjoy smaller file sizes in all simulations, not just smoke. I also wrote quite a lengthy post about everything point caches to the new code.blender.org blog, so check out that too (even if you're not so much into the technical stuff there are some ideas about future functionality in the end which you people might find interesting ;)

2. Hair children now have parting controls, a long hair mode and kink flatness. More about these in a demo video as soon as I have time to make one!

3. I finally merged Stephen Whitehorn's (chickencoop) viscoelastic sph particle springs patch to trunk, so there are some nice new options for fluid particles. I'll try to make a demo video about this too, so expect to hear from me again soon :)

Texture coordinates introduction video

Here's the promised video.

Particle texture coordinates

For a long time now Blender 2.5 particles have been crippled in the way that you couldn't animate particle material properties like color with particle age. In Blender 2.4x this was accomplished by creating an ipo-curve to a material property and then by some magic the frame range 0-100 was mapped to the particle life time. For me this always felt very unintuitive and hacky, so when the feature got naturally broken with the animation system update for 2.5 I didn't really feel like reimplementing the feature until a proper way of doing this was found.

To make a short story even shorter yesterday I found the way :) For quite some time textures that were applied to hair strands have had the "strand" coordinate option, which uses the point along a hair strand as the x-coordinate of the texture lookup. I simply upgraded this option to "Strand/Particle", so for normal particles this coordinate option now uses the particle age as the x-coordinate. Simple and extremely powerful! As an additional feature the y-coordinate is mapped to the location of a trail particle, so particle trails can be faded and colored nicely too!

I'll try to make a short introduction video to this functionality in the near future, but for now I hope you have fun playing with this! Some more technical information in the commit message.

SPH fluid particles, oh my!

It seems that the SPH fluids had a quite big problem in the way the algorithm was implemented. The problem in the implementation led to things like this:

Oh my indeed! Not very physically correct looking! The fluid particles drop straight down to a horizontal collision surface, so how can there be big sideways motion in just one direction? Oh well.. after a day of furious coding the algorithm is now much better implemented and here is the result with the exact same settings:

The fluid doesn't really look the same because the calculations are done differently, but at least it seems much more physically correct as the fluid spreads evenly in all directions and not just one. After some parameter tweaking here's the final result:

Ahh, much better! For technical information see the commit message.

But there's more! As a result of this new correct implementation I hear Stephen's viscoelastic springs addition to SPH paticles is more stable than ever. He was also kind enough to upload some quick teasers of what's to come:

Oh how time flies

My sincere apologies for keeping silent for so long, but it seems that there has just been too much happening in my life to have time to post updates. Not much happening on particles currently, but here's a quick recap of what has happened since my last post.

As some of you may already know I got a 7 month job from the Blender Foundation as a part of the 2.5 support team! The current main goal is getting Blender 2.5 out of beta, so bug fixing is what I mostly do these days. Currently I'm keeping busy with non-particle bugs, but that's only because the 2.5 bug tracker is already pretty much free of particle bugs. I dare you to find me some more though as the goal is to have 2.5 ready for serious work!

As part of the bug fixing I refactored the particle collision response code to be much more stable and robust. So no more leaky/freaky collisions for particles! Real new features are a no-go before 2.5 is out of beta, but that hasn't stopped others from tinkering with cool stuff for the future.

Raul's fluid particles were committed before the feature freeze and I currently have a patch to review from Raul and Stephen that implements plastic spring behavior to the fluid (sticky goo here we come!). This feature will hopefully be ready when the feature freeze ends! You can read more about fluid particle development in Raul's blog.

Lukas Tönne has also been busy with node particles and more. I haven't yet had much time to check out his work but I've been hearing many good things and have high hopes for this project! More info about this in Lukas's blog.

I still think it would be a good idea for me to start making video tutorials on various sides of the particle system, but I just never seem to have the time to sit down and start recording. I also have a huge todo/ideas list for particles and proper development will surely continue once the feature freeze ends.

To finish here are a few teaser pics of a what could be possible in the future with just one particle and some code I have laying around :)

No more bugs please!

Sorry again for the lack of updates recently, I have a boid basics tutorial waiting to be recorded, but unluckily I'm still too busy to really get into it.

But that's not the reason for this post, because now I've totally had it! Yesterday I finally had a tiny bit of time to check on the state of particle bugs in the tracker and what do you know I start fixing them one by one and notice that it's really nice to do some proper particles coding again. Then along comes today and I get this terrible urge to actually code some features! "It's been too long since I've been out having fun!" cries my particle brain. So here we are with some small updates to hair dynamics and I didn't get a single thing done from the actual work I was supposed to do today!

So I'm asking you guys, no more particle bug reports unless you really want me to code some more features! The withdrawal symptoms are getting stronger and every day it gets harder being away from particles ;)