I Spy

Original Status

Final

Project proposal

Modeled props & Adjusted the existing animation

Reference

Balloon Simulation

I used the Vellum solver to create the balloon pop simulation and added collisions for the falling pieces. However, this approach did not allow the torn pieces to interact properly with other colliders.

I modeled and refined additional props in Houdini—particularly those involved in the simulations—and positioned them in relation to the existing scene elements.

I set the pivot point for the ones that need to be animated and key framed them accordingly.

The objective of this project is to enhance the scene by incorporating additional simulations and placing more models to occupy the empty spaces. This work was initially developed for my VSFX350 course as part of both a complex scene and an animation project. While the course requirements were met, the project remained unfinished, and I am continuing to refine it beyond the class.

Sand Simulation

Friction: 0.2
Dynamic Friction: 1
Attraction Weight: 0.1

Friction: 0.2
Dynamic Friction: 1
Attraction Weight: 0.5

Friction: 0.2
Dynamic Friction: 1
Attraction Weight: 1

To address this, I revised the setup to manage both the simulation and collision handling entirely within a single SOP network. I also adjusted the mesh structure slightly to achieve smoother collision results.

I created the sand simulation using two SOP-level setups: one for generating the sand shape before it falls, and another for the actual simulation, where the sand collides with a dustpan and cone while falling into the box.

I manually adjusted the gravity force and velocity damping values to refine the simulation and better replicate the physical characteristics of sand.

Substeps: 5

Substeps: 6

Substeps: 8

After several tests with different parameter values, the final version was set as follows.

Friction: 1
Dynamic Friction: 0.5
Attraction Weight: 0.2
Substeps: 6
Static Threshold: 3
Dynamic Scale: 0.5

Houdini 19.5.640 | Redshift | Render time: 3 mins/frame

For the sand inside the basket, I applied the same approach. The original basket mesh had unsuitable collision geometry, which prevented it from recognizing the hollow interior. To resolve this, I remodeled the basket and simulated the sand using the Vellum solver. Since this sand was intended to remain static, I rendered a single frame and kept it visible throughout the entire sequence.