I have no intention of starting a vs war, but I just wanted to know from this community how houdini fluids (specifically liquid sims) compare to those generated by realflow? My main criteria are realism, speed and directability. I have a bit of free time to learn a fluids package and I'm trying to decide whether I should learn houdini or realflow. I would consider myself an intermediate houdini user and I like all the control the package provides. I just wanted to know if it was able to generate realistic liquid sims in a comparable time frame.

Thanks

I'm wondering the same thing as you.

I don't have too much experience with it, but at the current state, you can definitely create realistic simulations in Houdini, BUT it's not even close to comparable in speed (hopefully sidefx will improve on this). Houdini straight away offers a better system for controlling the simulation by being able to modify the solver how you see fit (via the microsolvers), and via all the other Houdini awesomeness. Realflow, however is by far the faster one when it comes to fluids, but at the cost of control… as soon as you start adding in control to realflow with scripting, you start to lose a good bit of speed, though I'd still wager it's generally faster even with a lot more particles and a complex scripting setup. (Realflow5 is supposed to have an sdk if you're into C++, so you can speed stuff up there) Another thing to keep in mind is that Houdini also has voxel fluids, and the ability to combine them with particles, which realflow4 does not have (but Realflow5 will). Houdini does offer a few things that realflow doesn't though, like distributed sims, which probably help a lot if you have a renderfarm (can't test this with the apprentice version however).

..My 2 cents…

P.S. Naiad is the one to look out for though… Not sure the release date, otherwise I'd say just learn this for fluids… http://www.fxguide.com/article606.html [fxguide.com]