week 1 Refresh on Houdini 3/10/25

Things to know about Houdini:

The default grid Unit measurement in Houdini = 1 meter

String = A name. Data that the computer stores with nothing but a name attached to the set data

Integer = Whole numbers (5, -10, 67)

Float = Numbers with decimal points (0.54, 43.43, -3.22)

Character = Represents a single letter, digit or symbol (A, 1, !)

Boolean = True or False, Yes or No. Anything that has two outcomes/choices

Vector – measured point in space. Tell us how much and where?

There is multiple layers/Networks in Houdini. A lot of the work is done in the obj network.

Setting up in Houdini

The first thing I did in the first week of environmental FX was setting the layout. Making sure the menus were suited to me and the work I would do in future lessons.

The new layout had the geometry spreadsheet located below the scene view. Also the parameter box is split in to 2 so I can view different nodes at the same time.

Creating a Boundary for the surface in Houdini:

The box has gone through the grid plane because we increased the transform values.

We can prevent the box from falling through the grid plane with a Matchsize node.

By changing the Justify Y to minimum the box will now sit on top of the grid.

Domino

Added a box node with dimensions for a domino shape. The poly bevel node below it gave the dominoes smooth edging.

The unwrap node gave the shape some UV’s.

Null to refer to the Domino later on.

Used a curve node to draw points round in a domino shape where they can fall on to each other.

Resample node to create points on the curve for more dominoes to be placed later on.

Copying the dominoes to the points on the line

Week 2 10/10/25

Particles

This lesson we focused on Houdini’s particle system.

A trail node makes motion trails. Generates trails for points in the input geometry.

A dopnet is “Dynamic Operators”. This is used for building networks to create simulations. Simulating how object react, how forces are applied and the emission of particles. This node takes in data such as mass, gravity, velocity, size and simulates the scene using the inputted data.

Withing the Popnet is a network where nodes for simulating particle effects can set up.

The popsource us responsible for spawning particles. Controlling the production of the particles, birth rate, Velocity and more.

Popwind does exactly what it sounds like. Which is that it adds wind physics to the particles in the network.

A popstream isolates a specific group of particles and can set bounding boxes for the particles.

In this case if a particle had a higher position than 3 the popstream would set a bounding box to the particles.

Above is the particles lifting off in the scene view

popwwrangle is where command prompts or code can be written in.

This code changes the velocity based on the particles number.

A poplocation emits particles in all directions. It can control the life of particles and give particles an id.

popobject allows for particles to interact with other object. Changing behaviours of simulations for the particles.

Controls the generation and manipulation of particles. Updating particles according to their velocities and forces.

As you can see the particles have a set velocity causing the particles to shoot up before dying individually after 3 seconds ion the air. The gravity in this simulation is set to 0, allowing the particles to fly up without any forces pulling it down.

With the Gravity I can make weird movements in the particles making it zigzag before it lifts off. As well as making it crash down causing it to bounce a bit on the ground plane.