VFX Animation | Angel Digital Sketchbook

We covered the basics of Houdini, focusing on moving objects around, scaling, and rotating them. We also got familiar with the interface and learned how to split the Houdini workspace for easier access and manipulation of tools.

I started by creating a Geo node at the OBJ level, renamed it, and dove inside. Inside, I placed a Box node and adjusted its dimensions in the parameters to represent the cheese. Next, I added a Color node to give the box some color.

To distribute points across the surface of the box, I used a Scatter node. Then, I created a Sphere node and tweaked its dimensions if necessary. Using a Copy to Points node, I connected the spheres to the scattered points on the box surface.

To randomize the size of the spheres, I added an Attribute Randomize node, targeting the Pscale attribute. Finally, I brought in a Boolean node, set it to subtract mode, and used it to cut out the randomized spheres from the box, creating the cheese holes.

Then we hade a fun with puzzles, we also make an Ice cube

Week 2: Rigid Body (RBD) and Domino effect

I attached an RBD Bullet Solver node to handle the collisions. Initially, the dominos were falling without any collisions, so I added an Attribute Delete node to remove the velocity attribute, ensuring the objects wouldn’t move until they were collided with. Then, I created a Box to act as the colliding object and connected it to the RBD Bullet Solver node to interact with the dominos.

WEEK 3: Ducks on Water

I used an Attribute Blur node to smooth the curves of the water surface, ensuring a natural flow. Next, I added a Normal node to properly orient the duck model so it sits correctly on the water surface, following the curves as it animates. To hold the duck in a stable position, I used a TimeShift node with the $FF expression to lock it at frame 1, creating a Rest Point Lattice.

I then added a Scatter node to distribute points across the water surface and used an Attribute Randomize node to vary the sizes of the ducks by targeting the Pscale attribute. With a Point Deform node, I connected the scattered points, the TimeShift rest point (to keep the duck stable), and the water surface (referenced via an Object Merge node).

Finally, I brought in the duck model as an FBX file, adjusted its orientation with a Transform node as needed, and used a Copy to Points node to place the ducks on the scattered points across the water surface.

Lego + rendering setup

Week 4 – VellumCloth

Houdini’s cloth simulation uses the Vellum solver, which is based on Position-Based Dynamics (PBD). This solver is efficient, flexible, and allows for real-time tweaking of properties like stretch, bend, and tear. You can use it for everything from clothing on animated characters to flags, curtains, and even soft body effects.

Key Nodes for Cloth Simulation

Vellum Cloth: Converts geometry into a cloth object with constraints.
Vellum Solver: Simulates the cloth dynamics and handles interactions with forces and collisions.
Remesh: Increases mesh resolution for finer simulation details.
Vellum Constraints: Adjusts properties like stretch, bend, or tearing resistance.
POP Force/POP Wind: Adds environmental effects like wind or turbulence.