Roger Beltrán - FX Reel 2024

MAGICAL FIRE SHOT

Made in Houdini FX, rendered in Karma XPU and composed in Nuke.

The goal of this project was to create an anime-like fire effect. For this I used a character and animate it with Mixamo and then simulate the cloth with Vellum. For the main fire effect, I used a custom particle simulation to guide a Pyro simulation, from which I'll end up using the velocity field to advect the final particles. For the enviornment I created a fire background with Pyro to create some depth. Finally I added some embers with a particle simulation and a procedural ember model.

Vellum Cloth Simulation

Magical Fire Particles Process

To create the effect that the particles are driven to the sides of the character, I used the technique of creating two points to where the particles have to go. Then, inside the pop simulation, in a Geometry VOP, i subtracted the position of the destination points with the current position of the particles to set the velocity. And then to give it a curved effect I created lines from the destination points to the center of the character. And then using the nearpointrs function drive the velocity towards those lines.

Composition in Nuke

I use a few techniques such as Chromatic Aberration, Glow for the main effect, and Distortion for the heat effect to create this final render.

T-REX ATTACK SHOT

Made in Houdini FX, rendered in Karma and Composed in Nuke.

The goal of this project was to create a Ridigbody Simulation of the building and the street, and also to create new tools in Houdini to ease the work and improve the workflow of the RBD Simulation of the different materials of the builing.

Custom tools for RBD workflow

The first task was to create this eight tools to improve the workflow of all the project. This tools are helped me to automate all the techniques that would repeat though all the work.

Preparing the RBD Simulation

For the actual simulation of the building, fist of all I had to separate all the different materials of the building to properly fracture them as they should. For this building the materials were: cement, concrete, ceramic, plaster, wood and glass.

After the fracture I faced the challenge of custom clusters. In this shot I wanted that the Dinosaur took out a piece of the building with the mouth. For that I had to configure a way to create the cluster exactly where I wanted. I modified the cluster constraint that I did to add a cluster origin from a certain point that I connected.

Finally for the setup of each material, i setted up the constrains. Using the custom tools, I could choose the constraint type and the exact geometry I wanted to affect. For example, this is the tree for the cement setup using the tools:

In this case I configured a Cone Twist constraint, a general GLue constraint and a harder Glue Constraint by element to connect the walls with the border of the window. Also, I broke the constraints usign the clusters mentioned before.

Simulating the main pieces

I did separate the heavy elements and the softer ones (like the wood and the glass), so I could simulate the heavy parts first and drive the overall simulation where I wanted faster. This way I used the RBD Solver tool that I created before to simulate all 4 heavy materials first at once. This is the DOP Network setup:

TO make the simulation exactly as I wanted I did a few tests beforehand to define all the weights and constraints. I used TOPs and Wedges to make different variations.

And these are the results of the simulations of the main heavier pieces, and the lighter ones:

Dust and Debri

From the already simulated pieces, I emitted particles advecting the velocity of the pieces. This particles can separate in two groups: the small debri and the big debri. Depending of the velocity and the size of each piece a lot of particles are emitted. The bigger ones will render as rocks, and the other ones will the used to create a Pyro smoke simulation which will the the Dust.

Render and Composition

I did render the whole scene in Karma. I imported all the different elements and render the separately to composite them better in Nuke. Then, there I gave the overall look of hard constrast, simulating a black and white old movie.

DR. STRANGE PORTAL SHOT

Made in Houdini FX, rendered in Mantra and composed in Nuke.

The goal of this project was to recreate the effect of the Dr. Strange opening portal. I use a few particles simulations and a few pyro simulations. I did all the modelling and shading of the enviroment in Houdini. 

Creating the main shape of the portal

The key of this effect is the base shape of the portal. I has to have good weigth, and good feeling. For this I created a circle and the modify it with some noises and some VOPs to give it a good feeling. Then from this I animated it and scatter it with a mask to emit the particles from where I wanted. I did a few variations to render them separately. With the trail node and the use of the id of each particle I could strech each particle so they are a little line exactly as I wanted. This is the node tree of some of the simulations:

Adding smoke to the effect

For more reliability IO added three layers of smoke. Two of them are driven by the velocity of the rotation of the portal. I used negative disturbance in one layer to drive the smoke to the center of the portal creating a vortex effect. Also I added an ambient smoke that dissipates when the portal opens for further integration with the scene.

Modelling the scene

Rendering all variations and compositing them

Finally I rendered all sparks variations separately so I could composite them with a lot more control.

Thanks for watching!!