Sam Brimlow

I wanted to take another go at recursive growth in Houdini, but this time, instead of generating points, I used masks to control where the growth happens.

The Idea

I wanted to see if I could control growth in a more organic way by using masks rather than just generating points. The idea was simple: use a mask to determine where growth could occur, allowing new branches to appear in specific areas while keeping other parts static. By adjusting the mask over time, I could steer the growth and create a more natural-looking expansion.

The Process

Instead of spawning new points, I used attribute masks to tell Houdini where the structure should grow. The setup was pretty straightforward:

• Start with a base shape – Something simple to build from.
• Use a mask to define active growth zones – I used a procedural noise function to control which areas would expand.
• Let the geometry grow based on the mask – Higher mask values meant more growth, shaping the form over time.
• Refine and tweak – By continuously adjusting the mask, I could guide the shape’s expansion in a way that felt organic and unpredictable.

The Outcome

This approach gave me a lot of control over how the structure evolved, and the results were pretty interesting. It was a little closer to a plant/coral look than my previous attempt, and the fluid-like quality felt really organic. Seeing how the mask influenced the shape in real-time was super satisfying, and with some tweaking, I might be able to create something that more closely resembles corals and aquatic plant life.