David Marcus Santoyo
Legacy Portfolio c. 2005

EFX / Animation

Fluids RealFlow 4

Here is a sample of water pouring into a glass using RealFlow4 piped

into Houdini

Dynamics - DOPs in Houdini / Global Illunination GI

Here is sample of using Dynamic Operators in Houdini (DOPs) in conjunction with using Houdini's Physically Based Rendering (PBR) or Global Illumination. In this scene DOPs are used to create the shattering effect of the glass. Ambient Occlusion one of the techniques of Global Illumination is used in the surrounding areas.

Static/Plasma Ball

This Image was created using Houdini 9.1. I created the static electric tendrils from scratch are made into a "Houdini Digital Asset". The asset can then be attached to another instance of the asset, and so on. The asset can be attached at any position and then animated on the UV space of the previous bolt asset. This is a work in progress and I am ultimately trying to get the fluidity of plasma as well as a the unpredictability of the electric bolt. These abilities are built into the EFX rig / Digital Asset. All of the shaders are generic. The effect was enhanced in Houdini's compositor.

PARTICLES

The idea for the 3 helical "beams" of paint coming from the "Ray Paint Gun" was all mine.
I was given the responsibility for Research and Development on the EFX Rig for this shot.
I tried using Houdini Particles (POPs) & Forces in a number of different configurations and even developed a Dynamic Operators (DOPs) version of the EFX Rig for the shot. The main problem was the "scale" of the "World" that was chosen for the film, which was in very large units
( instead of a normally reduced scale ) and for a reason that I can't remember we couldn't reduce the scale for the shot. This caused the particles to become less controllable. In the final rig control was gained by passing the static helical particles through a deformer and then hand animating the deformations, this was done deftly by the EFX Animator that I was assisting. Also worth mentioning is the method used to "paint" the Red, Yellow, and Blue beams into a painting; I used Houdini's Attribute Transfer Surface Operator (SOPs) to transfer the final particle's hit position color to the particle by running the particle simulation and caching the color. The simulation was run a second time, and the cached color was transfered to the painting thusly.

SMOKE
This next series of images is an example of the Volumetric smoke used for the "Time Machine which the main characters travel through time with. I was responsible for optimizing the render times. This was done both in Houdini & Maya. Houdini Particles were used for the animation, then were translated to Maya, where Disney developed its Volumetric Shader. Note how much the volume is dialed down in the final Shake composited images.

Frame 9

Frame 16

The Same Frames in the final composited images :

Frame 9 again (the now black smoke and added vapor trails)

Frame 16 again

FLUIDS (more)

There were many scenes where Real Flow Meshes needed to be cleaned up in Houdini, using the Cookie Operator (SOPs) or Soft Peak / Peak Operators (SOPs). Below are two example of the type of Real Flow fluids, that I worked on, which required this. Also in the PBJ shot below
I used Houdini's Paint SOP to paint in appropriate peanut butter and jelly where Real Flow got a bit untidy.

Radioactive Material

Peanut Butter and Jelly (PBJ)

FIRE
Here is a sample of an older Fire Shader done in Houdini. This was done as a modified/adaption to the "Fire Vop" (Vex Operator) that comes in Houdini. It is a 3-D fire as opposed to 2-D fire done with sprites on particles. The geometry is particle / metaballs converted to polygons. The trick in the shader is to use the dot product of the "Camera Eye Vector" and the "Geometry Normal Vector" which give the effect of transparency near the central core of the geometry.

Hosted by Yahoo!

David Marcus Santoyo Legacy Portfolio c. 2005

EFX / Animation

David Marcus Santoyo
Legacy Portfolio c. 2005