Unit length = 1m
Unit mass = 1kg

vex functions

geo
Assemble
Connectadjacentpieces
Peak
Creep

Network editor

A dotted line means that it's referencing a certain node (so for example, no extra particles will be added(check with the middle mouse))

Object = Object type nodes in an Object type folder. These Object nodes allow you to build transform constraint hierarchies. Geometry type Object nodes contain SOP nodes that construct and modify geometry that inherits any transforms at the object level.

SOPs = Surface OPerators or geometry nodes that are inside an object folder. These are used to construct and modify geometry. Any kind of geometry from polygons to volumes.

DOPs = Dynamic OPerators or simulation/solver nodes that are used to construct simulations. Simulations read in geometry from SOPs and pass this data into the DOP solvers.

SHOP = SHading Operators are materials that represent a shader to apply to geometry. Some are hard-coded with vex and others are folders that you can dive in to and modify the VOPs inside.

VOPs = Vector OPerators inside VOP network nodes are used for everything from building shaders to modifying geometry, volumes, pixels, and more.

VEX = Vector Expression Language. The code language used to write shaders. VOPs are wrappers around VEX code snippets.

CVEX = Context agnostic Vector Expression Language. This has replaced all the VEX specific contexts throughout Houdini. It is a generalized language that uses the same environment and functions anywhere inside Houdini.

COPs = Composite OPerators in composite type folders. Used in image compositing operations.

ROPs = Render OPerators in side ROP Output directories that are used to create render output dependency graphs for automating output of any type of data and for triggering external processes like rendering. Commonly used to generate sequences of geometry, simulation data and trigger Render tasks that generate sequences of images to disk.

CHOPs = CHannel OPerators used to create and modify any type of raw channel data from motion to audio and everything in between. Most users safely ignore the CHOP context, and so can you, for now. Put it on the “get to it later” list when learning Houdini. But definitely keep it on the list.

Operator Type Library (or Houdini Digital Asset library)

First, download ImageMagick
In C:\Users\flori\Documents\houdini20.0\houdini.env file, add

PDG_IMAGEMAGIC = "C:\Program Files\ImageMagick-7.1.1-Q16-HDRI\magick.exe"
PDG_FFMPEG =  "C:\Program Files\ImageMagick-7.1.1-Q16-HDRI\ffmpeg.exe"

Houdini shelf tool for fast theme switch TextToMtlX

centroid(surface_node, type)
detail(surface_node, attrib_name, attrib_index)

Remove Points by ID

if (rand(@id*ch('seed'))>chf('ratio'))
{
removepoint(0,@ptnum);
}

Create vector based on relative location from point 2nd input

vector a = point(0, "P", @ptnum);
vector b = point(1, "P", 0);
@v = (a-b);
@v *= chf("mult");

Point normals outward

vector a = set(0,0,0);
@N = normalize(a + @P);

Change particle size in LOP's
In Primitive, select “All Geometry Primitives”
Also tick on “Run on Elements of Array Attributes”

@widths = ch("pscale_mult");

Houdini School
Theory accelerated
Particles
Rohan Dalvi

VEX-snippets
JoyOfVex
VEX for artists

CG Wiki
Houdini Resources
The Vault Manual
Applied Houdini
HoudiniSimon
Nick Taylor
Houdini Blueprints
Convert hipnc to hip files
Getting Started With Houdini
Nitzan Tregerman
Jake Rice Blog
TOPs
Blooming flowers
Simulate Paint Smearing
Unwrapping
Pixelfondue
Konstantin Magnus
Andreas Kjær-Jensen
Creating an CGI Crystal

Creating Lightning with VEX

Labs project Dryad Biomes Terrain Handbook Procedural Rocks Integrating a Road into a Heightfield Project Pegasus Procedural racetrack tool

Intro to Houdini Volumes, Clouds, and Volume VOPs

Spiral skinning
Rig fur dude with KineFX
Apex rig
Generating folder structures
Process Multiple Objects with TOPS
2D animation
Animating Characters

How not to suck at Python

richlord
superphotoreal.gumroad
Examples of Neural Networks built with VEX

What I Found

SOP Quicktips

COP Quicktips
Crystal Fluorite in Houdini 20.5
How to Create Organic Textures

Product Proceduralization
TOPs Masterclass

Solar Eclipse
MultiShot Workflows
Intro to Solaris

John Kunz UI Customizations for Houdini 19

Files in the packages folder

{
    "env": [
        {
            "HOUDINI_USER_PREF_DIR": "P:/Houdini__HVER__"
        },
        {
            "HSITE": "P:/Houdini"
        },
        {
            "HOUDINI_DESK_PATH": "P:/Houdini/desktop"
        },
    ]
}

First, download ImageMagick
In C:\Users\flori\Documents\houdini20.0\houdini.env file, add

{
    "env": [
        {
            "PDG_IMAGEMAGIC": "C:\Program Files\ImageMagick-7.1.1-Q16-HDRI\magick.exe"
        },
        {   
            "PDG_FFMPEG": "C:\Program Files\ImageMagick-7.1.1-Q16-HDRI\ffmpeg.exe"
        },
    ]
}            

Houdini.env $HOME Houdini Environment Setup Houdini Setup HSITE

Megascans Karma USD