Houdini 18.5 Destruction

Introduction to Material Based Destruction Getting Started

Loading the source scene and exploring it.

On this page

About this tutorial

This tutorial will introduce you to the basics of Houdini’s Rigid Body Material Based Destruction workflow using the RBD Bullet Solver SOP. It assumes at least a beginner’s understanding of Houdini. Topics covered will be:

  • Preparing geo for destruction

  • Using the RBD Material Fracture SOPs

  • Bringing in a custom hitting object

  • Organizing your network for best workflow

  • Tweaking constraint and material properties

  • Creating intra-material constraints

  • Using multiple constraint types

  • Configuring glass for rendering

  • Debugging and tweaking simulations

Before you begin

This is a guided tutorial. This means a lot of tedious button pressing has been automated, so you can concentrate on setting properties and values that make a difference.

Note

You can only do this tutorial from inside Houdini. You must display this page from a running Houdini session, just as you would load example files from the help docs.

To start, press the Load button below to load the required Houdini Digital Asset into your scene. The HDA contains a node that has buttons, which will create nodes a few at a time for you. At any time you can build the finished network in its entirety to see how it is supposed to work.

After you've finished this tutorial, it would be a good idea to start again, and try to do it by yourself from scratch with only the text in this page to guide you. If you want, you can run two Houdini sessions side-by-side (and copy and paste nodes from one to the other) to help you through it.

At the end of this tutorial, you should have a simulation that looks something like the animated gif above. However, it’s important to note that your simulation may not be identical, due to various reasons:

  • Minor changes to parameter values can have large changes to a simulation.

  • Software updates between when this tutorial was written and when you do the tutorial might introduce changes to behaviors.

  • Rendering with motion blur can introduce changes to your simulation.

Tip

Remember to save your scene file frequently as you work. For example, rbd_tutorial_step1.hip.

Note

Any value in the Houdini parameter interface that’s in BOLD is not the default value. To return to default values, right-click the parameter or folder and choose Revert to Defaults.


BEGIN

Load Digital Asset and Explore

Load the digital asset by pressing the Load button above. This will create a new digital asset for you called RBD Material Fracture Tutorial. The parameter pane will show buttons that are grayed out.

Note

The Load button will only open the file if you are running a help browser from inside Houdini.

Double-click the rbd_mf_tutorial1 node to dive inside, and you will see a node network that looks like this.

Double-click the wall object, (or select it and press Enter) to dive inside to the SOP level. Here you will see the finished node network. If you turn the display flag on the last SOP in the chain (rbdbulletsolver1) and press in the playbar, you will see the wall get destroyed by the hitter object.

Note

It will take a few minutes for the various RBD "materials" (glass, wood, and drywall) and constraints to be built before the scene will begin playback.

The Wall Asset

Inside the wall object you will see a Subnetwork SOP called wall1. Double-click this SOP to dive inside.

This wall is built simply so that we have some light-weight objects to work with. Here are a few things to keep in mind when building geometry for destruction:

  • Do not allow the geometry to intersect.

  • All geo should be “manifold” (meaning “water tight” or without holes). This is why there are numerous Polyfill SOPs in this network. If there are openings in the geometry, this node will fill them, (this often happens after boolean operations). If there are no openings, it will simply do nothing.

  • Each type of material is grouped. You will see how useful this is later.

To get out of this SOP and back up one level, press U or click the level up in the network editor path above the network view.

Next Steps

See Introduction to Material Based Destruction Tutorial for the step by step tutorial.

Destruction

RBD Material Fracturing

Next steps

Guided Tutorial: Introduction to Material Based Destruction

  • Getting Started

    Loading the source scene and exploring it.

  • Tutorial

    Step by step introduction to material based destruction.