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Particles Part 07 - On POP Streams And How DOPs Work

Again it's time for some theory. We successfully used streams with the Plant Growth videos, but today I will dive deeper into how what streams are, and how exactly they work. We'll dissect some inbuilt nodes to understand how the opstreamname() expression figures out on which particle groups the nodes should operate. To understand all of this I'll give you an overview of how DOPs work, what the different connection types mean and in which order things are executed. Because POPs really are not...

Vellum 101 - Activating Grains

This is what happens when we travel: Grainy Mantra rendering for the intro, weird audio and a screencap that is mostly working. Nevertheless this is a quick and easy one: How to activate grains using an animated Group-SOP.

Particels Part 06 - The Curve Force Twister

This time we focus on a classic in particle simulation, a twister effect. This is an excellent opportunity to have a close look at the CurveForcePOP and all of its settings. The setup is quite straight forward. Not much VEX nor other custom code, but inbuilt standard nodes and mainly Hcript expressions. Nonetheless this tutorial teaches you a very important thing: To create interesting looking FX you'll need to add variance, variance, variance! We'll add quite a bit of it to all different asp...

Freebie: Redshift Thinfilm Shader

We recently had to create a physically based thinfilm shader in Redshift. This is the result. It's a slightly simplified version of this OSL shader from gamedev.net, implemented using purely Redshift nodes: gamedev.net/articles/programming/graphics/thin-film-interference-for-computer-graphics-r2962

Vellum 101 - Tearing A Bag Of Grains

Short quick video today - still working through your questions regarding Vellum. Today we'll set up an example combining tearing cloth and grains. The setup is pretty straightforward, just the simulation times are a bit steeper due to increased substeps. But I guess that's the fun :)

Particles Part 05 / 02 - Plant Growth With POPReplicate

Here comes part two of our ecosystem setup. This time we'll add branches to the growing stems from part 1. We investigate the use of the POP replicate further, discuss the differences between its two input ports and deal with inherited attributes. Finally we attach leaves to the newly created branches to finish the setup off. This is basically a typical real world example of a particle setup. After watching the tutorial you might want to extend the concept with more influences on plant growth...

Vellum 101 - Looping A Simulation

Instagram videos, trade show installations or video game menus all need this; Looping background animations. Pretty straightforward when you're animating the traditional way - just keyframes and curves. However it can get tricky when you try looping a simulation.

In this video we'll walk you through the steps necessary to build a very basic looping vellum cloth animation and a slightly more advanced one.

Particles Part 05 / 01 - Plant Growth With POPReplicate

Today we'll talk about a very important DOP. The POPReplicate. We'll create a particle system that generates procedural geometry. For this we have to create trailing particles that follow their parents locations. And we want to make the plants branch. For both we need to replicate particles.  In this first half of the Part05 tutorial we'll create the main stems and put leaves on them. You'll learn about inheriting attributes and POP streams while working on the setup. The second half of ...

Vellum 101 - Peeling Off

Recently we had to build a setup to peel off a piece of geo from an underlying mesh. It turned out more straightforward than we originally anticipated.

Here's how we did it.

Particles Part 04 - Tubular Flow With Vector Fields

After looking at particle theory we now understand that we can drive particles by altering their velocity instead of using forces. This video shows you how to use VDB vector volumes to store a velocity field and then use this to make the particles move. Filling a volume with vectors once, is a lot more efficient than doing the calculations for each particle in every frame. Plus, it's easier to visualize whats going on.

The tube splines are attached. You might have to relink them in the ...

Vellum 101 - Crushing A Can

Ever felt so frustrated you needed to vent? By crushing an innocent can?

Look no further: In this tutorial we'll go through the steps necessary to use plastic deformation in Vellum to crush a virtual beverage can. No real aluminum was hurt in this setup.

Vellum 101 - Balloon Popping

Often requested, seldom answered: How do you pop a balloon in Vellum?

In this tutorial we'll go through the steps necessary to disable pressure constraints if weld constraints in your simulation break. Useful not only but also for setting up a simulation of a bursting ballooon or bubble.

Particles Part 03 - The Principle Of Particle Simulation

After two episodes with practical examples it's time for some theory. In this episode I'll show you how a POP solver does force and velocity integration to simulate the particles. Equipped with this knowledge we build a custom POP solver with wrangles and show that it creates the exactly same results as the inbuilt POP solver. Although I know that theory lessons probably aren't the most populart ones I hope you enjoy this one anyways. As the setups will get more complicated later in the cours...

Vellum 101 - Stiffness Dropoff

Vellum 101 - Voronoi Cloth Bags

One of our very first setups we tried pulling off in Houdini.

In this tutorial we'll go over how to set up a bunch of connected voronoi cell shaped cloth bags that are held in place by a couple of strings.

Particles Part 02 - Conform To Surface

Same base object - brand new effect. Today we'll make particles conform to the underlying surface by using the double cross product. This is a standard technique for creating a surface constraint. In this video you'll learn how to pull off this effect and why wiring nodes inside DOPs can be different than elsewhere. We import reference geo to DOPs and use VOPs to build our custom constraints tool. So more particles it is - enjoy.

Attached you'll find the file I created while recording t...

Vellum 101 - Locomotion Using Fiber Constraints

Ah! The classic FEM setup: Weirdly moving, crawling softbody creatures that make you shiver in slight disgust. Good news: It can be done in Vellum too! Same level of disgust but faster simulation times. Fibre constraint galore!

In this tutorial we'll build an organically moving worm like creature using H17.5's new Vellum fiber constraint.

EDIT: Updated the scene file to work in H18 too. Solidconform doesn't properly promote attributes in H18.348, so it needs to go in before settin...

VEX101- Implementing A Paper: Hidden Point Removal

Time for a small add-on to our VEX101! I've been commuting quite a bit this year and when you find yourself sitting in an express train it can get boring. Luckily Jake Rice pointed me to a few papers, one of which was this one:

 http://webee.technion.ac.il/Sites/People/cgm/Computer-Graphics-Multimedia/Publica...

Vellum 101 - Blend Shapes

Ever had that moment when you stumble upon a node you for some reason missed until now? Exactly what happened to me when I saw the Vellum Rest Blend node. It's rather useful if you want intricate control over the shape of your Vellum simulation, however you are limited to meshes with the same topology. Nevertheless a fun and useful node.

In this tutorial we'll go over how to set up a sequence of blend shapes which we use in Vellum to drive the appearance of our simulation.

Particles Part 01 Addendum - Shading in RS

Here's a walk-through of the Part 01 particle scenes render setup. It's done in RS but a Mantra setup would look quite similar. This video explains how to genereate geometry for the particles on rendertime and how to setup shaders for the particles and the objects. All the materials are driven by the color values set on SOP level. 

The HDR I used can be downloaded here: http://www.hdrlabs.com/sibl/archive....

Particles Part 01 - Paint Removal

Hi folks. This video marks the start of a new course on Entagmas Patreon. Particles! Particles are versatile and visually interesting and Houdini is capable of handling tons of them. At the same time they are the easiest of all the DOP categories and well suited to dive into the world of DOPs. Starting with this video Manuel will give you advice on how to control particles and forces and of course about the inner workings of the POP solver. We'll pull off some pretty neat effects.

T...

Vellum 101 - New In Houdini 17.5: Per Point Friction

Yay! Houdini 17.5 has been released and while everyone is trying out PDG, we're focusing on the newest addition that's been brought to Vellum in this version: Per point friction. This allows us to control how sticky/slippery a given point in our simulation is.

In this tutorial we'll build a basic per point friction setup which allows us to reveal a logo (or any B/W image) by dumping grains on a plane.

Vellum 101 - Force Directed Graph

Force directed graphs are a popular way of visualizing the relationships within a given set of data. While the term might sound intimidating, the idea behind it is quite straightforward: For each connection between data points just span a rubber band between the points and let the resulting system of springs converge to a rest position. The resulting arrangement is a very intuitive visualization of the data's relationships.

In this tutorial we'll build a simple Vellum based f...

Vellum 101 - Connecting Wires

Admittedly I craved for a bit more VEX coding and I found rebuilding Manu's old "Connecting the Yarns" setup in Vellum to be exactly the right dose of coding I needed :)

In this tutorial we'll use VEX to dynamically create additional constraints which pull together individual wires while simulating.

Vellum 101 - Inflating Ballons Into A Shape

Another really popular question regarding Vellum: How do you inflate geometry so it fits inside an arbitrary geometry? Admitted - this can look neat and has a wealth of applications in motion design, so let's just do it!

In this tutorial we'll build a Vellum balloon setup that gets inflated to fill the shape of a letter.

Vellum 101 - Soft Constraining Grains & Soft Bodies

EDIT: Updated/Added Scene File For H19

Weirdly enough we've been receiving quite a few questions regarding soft constraining Vellum objects in the past days, so why not answer them in a short quicktip.

In this video we'll go over setting up soft constraints for animating vellum grains and soft bodies.

Vellum 101 - Twisted Wires

Again one of those posts where I lost the inspirational link. If anyone kows which festival opener I'm referring to (saw it on Behance) - please comment.

Apart from that pretty straightforward tutorial today: Setting up wires with different restlengths and then twisting them. Enjoy :)

Vellum 101 - Pills (Rigid Bodies & Grains)

Someone (sorry, my poor brain can't remember exactly who) asked if it'd be possible to combine bullet dynamics and Vellum. While we so far only found unsatisfactory solutions for this problem, there is another way of simulating basic rigid bodies in Vellum.

In this tutorial we'll set up a workaround rigid body solution in Vellum and have it interact with grains.

Vellum 101 - Swirly Cloth (Vellum + POP Attract)

In this one we'll have a look at how to use a POP Force like The Pop Attract and Pop Axis Force to direct where our simulation is moving.

Vellum 101 - Shrinkwrapping

Flavio asked how to attract vellum cloth to a piece of geometry - a setup we too need quite often. Not only can you use it to wrap virtual goods in packing paper, it also makes for some nice shrink wrapping!

In this quicktip we'll set up custom forces in our vellum solver using a bit of VEX.