Donut Breakup Simulation
This project was created for my Simulations 1 exam in the Soft Body category. The main inspiration came from The Crunch Studio's The Snatch, a Houdini simulation where a baguette is twisted until it tears apart.
My main goal was to create a convincing ripping effect for the donut and push the level of detail as far as I could. To make the rip feel more impactful, I also added a chocolate filling simulated with Vellum Grains that bursts out as the donut tears apart.
A big part of the project was figuring out which simulation settings gave the best result. To speed up this process, I built a TOP network that generated wedges for different parameters I wanted to test. The system automatically simulated each variation, rendered preview videos, and combined them into comparison montages, allowing me to review hundreds of iterations and quickly spot the versions I liked most.
The final result is a soft body donut simulation with detailed tearing, dynamic filling interaction, and a workflow that taught me a lot about Houdini's procedural tools and simulation pipeline.
The final render of the project. The first half focuses on the Vellum Grain tearing, while the second half showcases the donut's soft body falling on the plate.
One of the many montages my TOP system created. I let the system run overnight, and by the time I woke up, 200–300 iterations had been simulated, captured, and compiled into a montage. This particular montage was made for the Vellum Grain part.
Another comparison montage, this time focused on how the donut behaves when it lands. I wanted it to feel soft and alive, without becoming too stiff or overly squishy.
The goal here was to see what impact the paramaters of the donut's soft body simulation had on the chocolate filling, which was done with vellum grain. The softer the donut got, the more explosive the chocolate flies out of the donut on impact!
The entire node tree in Houdini. From prepping the geo for the simulations to meshing the output of the simulations to usable geometry!
The TOP network I used for creating the montages of the wedges.
The reference in question. All the credit goes to The Crunch Studio!