entagma

VEX 101 - An Honest Foreword

A word of warning and a basic explanation of what programming means.

Useful Links:

Matt Estela's cgwiki:

http://www.tokeru.com/cgwiki/?title=Houdini

Juraj Tomori's VEX Tutorial:

https://github.com/jtomori/vex_tutorial

Family Tree of Programming Languages:

VEX 101 - What's In This Course?

The (very) rough plan for VEX 101 is this:

General Topics:

- Learning programming/scripting fundamentals (vs. learning a programming language)

- Learning to help yourself (where to look up VEX'ing questions) 

VEX Topics:

- Learning VEX itself:

- Accessing Data

- Data Types

- Variables

- Conditionals

- Loops

- Arrays

- Functions

Misc. Other Topics:

- Basic math (bits of trigonometry etc. tha...

Volumes 101 - Something New

As we feel there is a huge need for an introductory course into VEX, we're halting the volumes course. If you feel there are (volume) topics that still need to be covered, please let us know in the comments! We might publish an addendum to the course if we feel the need, but for now we'd like to focus on bringing you an introduction to VEX as soon as possible. 

Volumes 101 - Art Directing Velocity Volumes

While editing last week's tutorial we realized that the central technique we're employing belongs to a whole group of neat tricks that we often use in produiction as they make for relatively compact yet powerful setups. We're talking about shaping a velocity volume to your liking.

Using a small bunch of tricks you can procedurally drive the direction of your vector fields and thus manipulate particles, sims and geometry to form any shape you can come up with.

Volumes 101 - "Dissolving" Geometry

As promised here's the technique we used to create the volume for last week's tutorial. It's a setup we find ourselves using quite frequently in commercial projects, especially when it comes to still renderings. Creating a velocity volume to drive your advection makes the behaviour and look of your volume extremely adaptable and art directable. Which comes in very handy when you're trying to meet a client's feedback :)

Volumes 101 - Volume Displacement Shader

EDIT: Reuploaded the scene file, forgot to attach one piece of geo.

Admittedly this is a deep first dive into shading volumes using Mantra and Houdini's mat-context. However we wanted to get this out of our system as we received quite a few messages asking how to achieve this effect.

It was popularized by the incredibly talented Lee Griggs (http://leegriggs.com/abstract-render) using Arnold.

H...

Volumes 101 - Juliabulb Using Volume Procedurals

What else can you create with volume procedurals? In this one we take a look at the archetypical example of what's possible with procedurals: We create a three dimensional Juliabulb fractal (Yes, you've all seen the Mandelbulb, but c'mon - this is a Juliabulb!)

As  a bonus we also threw in an openCL wrangle to generate the same fractal. 

Volumes 101 - Volume Procedural Basics

There is one brilliant thing that makes me use Mantra for special projects involving highly detailed volumes: Volume Procedurals. They allow you to evaluate a piece of VEX at render time and thus (efficiently) generate extremely high resolution volumes without the memory footprint those volumes would usually have. Hooray to Volume Procedurals!

This is an intro to the baasics you need to know to use  volume procedurals. We'll build on these basics in the coming week :)

Volumes 101 - Multistate Cellular Automata in OpenCl

"Yeah! More OpenCL!" (Most probably nobody. Ever.) Nevertheless - this one is a good exercise in writing your own OpenCl kernels. This time we'll build a cellular automaton. But not just the usual game-of-life types but a full blown multistate automaton. Have fun :)

Sources:

Softology Blog:

https://softologyblog.wordpress.com/2012/05/14/3d-cellular-automata/ 

Volumes 101 - Reaction Diffusion in OpenCL

Yes... Admittedly we implemented reaction diffusion already using only SOPs (and a tiny bit of VOPs). However this implementation was a bit limited and to offer the full scope of what reaction diffusion equations offer, we'll reimplement the setup - this time using OpenCL.

This will result in two things: First - a ten to fiftyfold increase in speed (depending on your hardware and setup parameters) and second - in us learning a bit more OpenCL.

Make sure to have a look at our previ...

Render Setup: Fakebroidery

Here it is - including a woven background and secondary strands in the yarns: Our Embroidery render setup.

Set up to render using Redshift.

In order to render properly you'll need to download the "Barcelona Rooftops" HDR from http://www.hdrlabs.com/sibl/archive.html

Full Res Artwork: Fakebroidery

Here in its UHD glory. Rendered in Redshift.

Volumes 101 - Custom Kernels in OpenCL

Admittedly this is as arcane as it gets in our course on volumes. Admittedly this is also the fastest (execution wise) it's gonna get. We'll have a look at writing and edge detection kernel using OpenCL. We'll be able to run our code not only on our CPU but (given the right graphics card) also on our GPU, thus speeding up the computation by orders of magnitude.

Volumes 101 - Kernels: Sharpening A Smoke Sim

Edit: As pointed out by Daryl in the comments (thanks, man!) I had a typo in the VEX code. Fixed & uploaded as volkernel_VEX_03_render.hip

This one deals with a rather important concept that is one of the basic building blocks of computer graphics: kernels. Admittedly this is pretty low-level stuff (as in "very basic operations" not as in "very stupid") and can be a bit tedious to grasp at times. ...

Bonus Setup: Frozen Sphere

EDIT: Added Houdini 19 compatible .hipnc file.

While preparing our current tutorial on how to simulate the growth of a snowflake, we received a question on how to create a freezing bubble. Good timing! Turns out that you can modify the snowflake setup to allow for some frosty ice crystals to form on a sphere. Attached you'll find this setup, ready to be rendered using Redshift.

P.S.: To render the final image you'll need to download the "Winter Forest" HDR from 2017-12-04 12:23:11 +0000 UTC View Post

Render Setup: Snowflake

You'll need to download the "Winter Forest" HDR from http://www.hdrlabs.com/sibl/archive.html

Set up for rendering in Redshift.

Here it is (250mb .zip): https://www.dropbox.com/s/dlo95i4rf2wioea/Snowflake_Render_Setup.zip?dl=1

Full Res Artwork: Snow Crystal Growth

Here it is in it's UHD (aka 4K) glory!

Full Res Artwork: Procedural Modeling Of Water Droplets

A fresh and juicy looking pumpkin in 4K glory.

Here's the free tutorial video: https://vimeo.com/243574191

Full Res Artwork: Dual Sculptures

The coral like structures of the extruded dual graph in 4K.

Dual Sculptures

Hi Patrons, today we present our first video of the new "Patreon Special" series. These are singleton quick tips that are  accessible starting with the "Render Swag" tier.

Using the dual graph of a triangle mesh and some mesh splitting by areas of similar curvature, Manuel guides you through the process of creating beautiful remeshings. A basic Redshift3D rendering setup is explained as well.

The setup uses the "Barcelona Rooftop" HDR that you can download for free from: 2017-11-27 08:04:09 +0000 UTC View Post

Volumes 101 - Point Advection

As a quick interlude before we're gonna dive into the ins and outs of wrangling volumes in VEX and OpenCL, here's some relaxation for our eyes: Building abstract line art using point advection.

Volumes 101: Adding Colliders To Our Solver

In the final video of our volume growth setup we'll add collision geometry to our solver in order to be able to further art direct where our growth is happening. I promise this is the last video for this particular setup. I feel we now have conquered most of Houdinin's VDB/SDF functionality and can move on to other neat volumetric setups :)

For rendering the visual used in our videos you'll need the Hamarikyu Bridge B HDR from 2017-11-17 07:37:15 +0000 UTC View Post

Volumes 101: Adding Forces To Our Solver

Adding forces into our solver helps us to create more intricate detail while being able to direct our growth according to the values of a vector field.

Render Setup: Quilling

For rendering this you'll also have to download the "Hamarikyu Bridge B" HDR from HDRLabs' sIBL archive: http://www.hdrlabs.com/sibl/archive.html

Here's the free tutorial video: https://vimeo.com/241376188

Full Res Artwork: Quilling

Two renderings this time. Still in their 4k-glory.

Here's the free tutorial video: https://vimeo.com/241376188

Volumes 101: Curvature Driven Growth

Let's combine our curvature measurements with volume advection to form the base of a rather versatile setup for organic (and sometimes a bit disgusting looking) growth.

Render Setup: Live Rendering Heightfields in RS

Here's the render setup for the japanese landscape in Redshift 3D. The file uses textures from https://www.textures.com/

The full tutorial can be found here: http://www.entagma.com/live-rendering-of-heightfields-in-rs/

Full Res Artwork: Live Rendering Heightfields in RS

The japanese landscape in 4K

The full tutorial an be found here: http://www.entagma.com/live-rendering-of-heightfields-in-rs/

Volumes 101: Curvature

Again a short intro to a very useful tool: Curvature. It will allow us to get an idea of the actual shape of our volume. This will form the base of another very versatile setup we'll be building and refining in the next tutorials.

Render Setup: Yarnworks

All set up in Redshift and ready to render at the press of a button.

To complete this setup you'll need to download the "Barcelona Rooftops" HDR fromm HDRLabs: http://www.hdrlabs.com/sibl/archive.html

The full tutorial: https://vimeo.com/237317079