A lot of interesting fluid dynamics come from reactions between different types of fluids. Here I show a straightforward and flexible way to set up FLIP sims to accomplish these kinds of reactions – which can include foaming / dissolving, hardening / thickening, expansion, etc.

Glue constraints in bullet are great – they’re fast and cheap – but by default they only break from impacts. Here’s a relatively straightforward way to break glue with arbitrary forces, including fields. Nothing overly complex, so it should be ok for all levels!

In this tutorial I look at a few ways to use fiber properties in the FEM solver to generate procedural motion. First, I cover a noise-driven approach to generating organic churning motion, and cover a bit about hybrid objects and wrinkly skin in FEM. Next, I show how you can use periodic functions and dynamic target constraints to generate inch-worm style locomotion. Finally, I show how you can set up a tentacle system that flexes towards an arbitrary animated target. Fairly straightforward setups throughout – should be ok for all levels!

New tutorial is now live. In this one, I cover a couple approaches to RBD-like fracturing simulations in FLIP. In the first version, I build the sim entirely in FLIP, using per-particle viscosity to emulate pieces. In the second version, I use a standard bullet RBD sim to drive a secondary FLIP sim. Along the way we cover a few other topics, including a quick look at dual rest uvs for texturing fluids. Enjoy!

Just posted another tutorial on how to set up a simulation with Pyro and FLIP solvers interacting. I cover a version where fuel and temperature are sourced from FLIP, while the pyro solver feeds back to consume and advect the FLIP sim, but the general approach can be easily adapted to a variety of different use cases.

Intermediate level. Assumes familiarity with VEX, SOP solvers in DOPs (see here for a refresher!), and some very basic familiarity with FLIP and Pyro in DOPs.

I hope you find it useful and/or interesting, and please comment or drop me a line if you’ve got any questions, ideas for improvements, or any tutorial requests! I’d also love to see anything you make using the setup!

Hip of the workflow (zipped because .hip files aren’t allowed by wordpress):

I’ve had a number of people ask me about this effect, and it’s something people seem to like a lot, so I’ve decided to put together a tutorial and an annotated hip breaking down how it works. The tutorial walks through the ‘standard’ version of the effect, from scratch, then I briefly discuss a few variations – which are also included in the hip!

Beginner/Intermediate level. Assumes basic familiarity with Houdini and VEX, but otherwise nothing wildly complicated!

I hope you find it useful and/or interesting, and please comment or drop me a line if you’ve got any questions, ideas for improvements, or any tutorial requests!

Annotated hip of the workflow (zipped because .hip files aren’t allowed by wordpress):

By popular request, I’ve just put together a tutorial on dynamic fracturing in Houdini. This is a long one (about 2hrs!) and heavy on the VEX and solver logic, but I’ve tried to make sure every step is shown and explained so you can build the whole thing from scratch with enough detail to improvise.

Intermediate/Advanced level. Assumes basic familiarity with Houdini, fracturing workflows, DOPs, and VEX.

As always, I hope you find it useful, and please comment or drop me a line if you’ve got any questions, ideas for improvements, or with any tutorial requests you might have!

I’ve also uploaded an annotated hip of the workflow so you can dig in at your own speed. (Note: zipped because .hip files aren’t allowed by wordpress)