Shot 1B Render Preview
It's been a bit longer than I would have liked since the last WIP for Judgement Day, but I've been a busy boy! Most of my time has been spent on prepping the FX and animation for this shot. This shot alone is almost as long as my second animation that I released, Teabag Tower!
Creating a TV Screen
Something I want to showcase is how to create a convincing TV screen in 3D. It's a lot easier than you'd think!
Mapping a traditional video onto a plane is a good start for creating this effect, but a staple of screens are the LEDs behind each picture! I've used a pretty simple repeatable LED texture (seen below), tiling it across the screen.
Then I overlay the LED texture on top of the video I'm bringing in. This creates the blocky screen effect that can be seen at the start of the shot as the camera zooms out.
String Physics
Something that I don't have to do often but enjoy are string physics! This is for the string that's attached to the ceiling fan inside of the living room. Creating the effect required a technique that I haven't used in a LONG time.
Let's break it down! To start, I created a single edge. This edge was then subdivided and then skinned with a "skin" modifier. This modifier takes an edge and envelopes in geometry. It can be useful for creating object like trees, but in this case I'm using it for a string.
I then run the string through a cloth simulation with the top vertex pinned so it simulates in place. Using animated wind and turbulence forces, I create an impulse that causes the string to act as if it were in an earthquake.
Now the fun part: attaching the little handle on the bottom of the fan string. This method involves copying the rotation and location information from a vertex group. Below is the constraint setup for the handle. When assigning the vertex group on the string, make sure that only the bottom vertex is influencing the rotation and location.
RBDs in Houdini
This shot also called for some RBD (rigid body dynamics) simulations for when the blast wave hits the house.
The first simulation that I worked on for this shot was the glass explosion. This explosion would only be visible from the side, but it's still an element I wanted to practice work on. Below is the node tree for the entire setup.
The first step of doing a simulation like this is fracturing. This is done using points scattered either within a volume or on a surface. In this case, I'm scattering the points on a surface.
These points are then used in a "voronoi fracture" node to finalize the fracture.
Adding the velocity is pretty simple. Before fracturing, I create a custom velocity vector in VEX, shown below.
After running it through a RBD bullet solver, you get the result shown above!
Vellum in Houdini
This shot also required some velum (cloth) simulations. I ended up using vellum not only for the curtains, but also for the power-lines! The setup for the curtains is below. All you really need is to make sure you have a pin group and set that inside of the cloth constraint.
Additionally, vellum was a good solution for the power-lines outside of the house. It's a similar method to the curtains, but I'm using 2 additional constraints.
Along with the standard cloth sim, I'm using a "strut" constraint. This essentially links each point to its neighbor, creating an internal rigid structure that preserves volume.
Exterior Dust
The last of the simulation work I did for this shot was for the dust outside for the fractured ground.
Sourcing for this effect was a bit unorthodox, but it worked quite well. To begin sourcing, I used a "mask by ambient occlusion" node to create a mask where the cracks in the ground were.
This mask when then used to narrow down the geometry for sourcing.
The workflow for the rest of the simulation remains largely unchanged otherwise.