Essential Houdini — Part 2

This is a two part series on core fundamentals of procedural content creation in Houdini.
Please be sure to read Part 1 first.

When learning Houdini for asset creation, or learning any other procedural system for artistic purposes, a frequent advice is — to “rewire” your brain. This is especially mentioned when coming from other 3D packages like Maya or 3ds Max.
This part explains what “rewiring” means.

Generally speaking, traditional or digital art is created from outside in. Artists start with big shapes/block outs/Silhouettes and then work there way in to define details, patterns, features etc…
This is partly due to how human visual system works. We see silhouettes, shapes before inner details. And also because that’s how an artist can define cohesive vision before diving into nitty-gritty parts.

On the other hand, software systems are generally created inside out. Meaning, components or Lego blocks are identified and coded which have plugs to fit with other components.
The reason for this approach is to promote reuse of components, distribution of tasks and realistic tracking of work being done. Just to note that even with this approach there is a high level vision initially laid out by system architect.

Houdini provides systematic ways to approach artistic creation.

For example, let’s say that you want to model a chair.

Instead of straightforward building it using polygon tools, you break it down in parts like legs, arms, seat and back-support — each part having its own specification and controls. When combined, they give you a chair.
Similarly if it was a building, it can be broken down into entrance, windows, outer walls, main facade and more…

Now, this looks like an overly complicated process to build just a model.
That’s because it is. Then why do it?

Approaching asset creation this way allows two major benefits (among few others) as opposed to diving in and creating one unique piece.

Variations
Once you have setup the system correctly, there is possibility of creating many different variations of the same asset type.

Iterations
As we build the asset in terms of Lego blocks, adding more details/features to existing system is possible while keeping all the previous systems functional.
Just a note here that, fast iterations are possible as long as you don’t try to make fundamental changes to the asset. I mean, extending chair system to output a sofa or even a seesaw works but not if its being morphed into bike.

I have tried to present and advocate procedural way of defining and creating assets in theses posts and I hope its somewhat clear.
Now for actually learning Houdini, Go Procedural has many good tutorials to get started.