Houdini Environmental FX:
week1: Basics of Houdini
We started with fundamentals of Houdini for visual effects. It covers the procedural workflow, node-based system, basic modeling, simple simulations, and an understanding of how Houdini is used in VFX pipelines for films, games, and commercials.
First we setup our own workspace , and rename it on our name for future use.
then we created a box with a geo node
we center it
and we bevel
test:
UVunwraped for Dominos
curves
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Integer: integers for whole numbers without decimals, such as counts, IDs, and frame numbers.
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Float: floats for decimal values to control precision, such as speed, size, gravity, and intensity in VFX.
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Vector: vectors to define direction and position, such as movement, velocity, and forces.
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Boolean: boolean values (on/off) to control conditions like enabling or disabling nodes or effects.
a powerful node that lets users write custom code (using the VEX language) to create, read, and manipulate attributes (like color, position, scale) directly on geometry, running over points, primitives, vertices, or details for high-performance procedural operations, effectively acting as a versatile shortcut to complex attribute tasks. It’s a low-level tool for expert users, replacing older, more specific nodes like Point Wrangle, offering greater flexibility and speed for complex attribute modifications.
week 2: Particles
We understand how we create, control, and modify particles using nodes to produce effects such as sparks, smoke, dust, and magic effects commonly used in VFX.
DOP Network (Dynamics Operator Network):
In this module, we use a DOP Network to create and control particle simulations. We learn how we simulate dynamic behavior such as movement, forces, collisions, and interactions, which are essential for realistic VFX effects.
week
Particles and Attributes: The Foundation of Houdini
Simulation Fundamentals: Initial Conditions, Solvers, and Vectors
Controlling Particle Behavior: Gravity, Friction, and Bouncing
Particles and Attributes: The Foundation of Houdini
Particles in Houdini are fundamental building blocks for creating dynamic simulations like smoke, fire, dust, and fluid effects. Attributes are data attached to particles (such as position, velocity, color, or custom properties) that control their behavior and appearance. Understanding attributes is essential because they allow you to manipulate particle properties procedurally, giving you precise control over simulations.
Simulation Fundamentals: Initial Conditions, Solvers, and Vectors
Simulations in Houdini rely on initial conditions (starting positions, velocities, and forces) and solvers (algorithms that calculate how particles or objects evolve over time). Vectors represent directional data like velocity or force, which influence how particles move. Mastering these fundamentals ensures realistic and stable simulations for effects like explosions, fluids, and rigid bodies.
Controlling Particle Behavior: Gravity, Friction, and Bouncing
Particles respond to physical forces such as gravity, friction, and collisions. Gravity pulls particles downward, friction slows them when interacting with surfaces, and bounce determines how they react upon impact. By adjusting these parameters, you can create natural or stylized motion for particles in environments, making effects like falling debris or bouncing sparks look believable.
Particles Emit from Geometry and Solvers
Velocity Inheritance and Attribute Calculations
Leveraging Streams and Conditions for Particle Control
Particles Emit from Geometry and Solvers
In Houdini, particles can be generated (emitted) from geometry surfaces, points, or volumes. This allows you to create effects like sparks from a surface or smoke from a volume. Solvers then calculate how these particles behave over time, applying forces, collisions, and other dynamics to make the simulation realistic.
Velocity Inheritance and Attribute Calculations
When particles are emitted from moving geometry, they can inherit velocity from the source object. This means if the geometry is moving fast, the particles will start with that motion, creating natural-looking trails or bursts. Attribute calculations let you modify properties like speed, direction, or color procedurally, giving you fine control over particle behavior.
Leveraging Streams and Conditions for Particle Control
Streams in Houdini are subsets of particles grouped by conditions (e.g., age, speed, or custom attributes). By using streams, you can apply different forces or behaviors to specific groups of particles. For example, you might make older particles fade out while newer ones accelerate, creating dynamic and visually appealing effects.
Week 3: Wall and ball Destructions
Rigid Body Dynamics: Simulating Objects with Shape and Structure
Configuring Rigid Body Properties: Density, Bounce, and Naming
Fracturing Geometry: Voronoi Patterns and Recursive Breaks
Rigid Body Dynamics: Simulating Objects with Shape and Structure
Rigid Body Dynamics in Houdini is used to simulate solid objects that maintain their shape during motion and collisions. This is essential for creating realistic physical interactions like falling debris, collapsing buildings, or bouncing objects. The solver calculates how these objects move and interact based on forces, collisions, and constraints.
Configuring Rigid Body Properties: Density, Bounce, and Naming
Each rigid body has physical properties that influence its behavior:
- Density affects mass and how objects respond to forces.
- Bounce determines how much energy is retained after collisions (elasticity).
- Naming is important for organizing simulations, especially when working with multiple objects or constraints. Proper naming ensures clean workflows and easy referencing in networks.
Fracturing Geometry: Voronoi Patterns and Recursive Breaks
Fracturing is the process of breaking geometry into smaller pieces for destruction effects. Houdini uses Voronoi patterns to create natural-looking cracks and fragments. Recursive breaks allow multiple levels of fracturing, making destruction more detailed and realistic (e.g., a wall breaking into large chunks, then those chunks breaking into smaller debris).
Rigid Body Simulation and Constraints
Fracturing and Constraint Propagation
Controlling Constraint Behavior with VEX Snippets
Houdini Code Lecture Overview
Optimizing Rigid Body Simulations
Generating Realistic Debris and Dust Effects
Optimizing Rigid Body Simulations
Rigid body simulations can become computationally heavy when dealing with large numbers of objects or complex interactions. Optimization involves techniques like:
- Reducing collision complexity (using proxy geometry or convex hulls).
- Adjusting substeps and solver accuracy for stability without unnecessary overhead.
- Caching simulations to avoid recalculating frames. These methods ensure faster simulations while maintaining realistic physical behavior.
Generating Realistic Debris and Dust Effects
Debris and dust add secondary detail to destruction simulations, making them look more believable. Houdini uses particle systems and instancing to create small fragments and dust clouds triggered by collisions or fractures. Techniques include:
- Using particle emitters tied to fracture events for debris.
- Adding volumetric smoke or dust particles for atmospheric realism.
- Controlling size, randomness, and timing to match the main destruction effect. This enhances visual complexity and realism in VFX scenes.
Week 4
we also created a dibris to simulate even further.
Debris Simulation Techniques
Optimizing Debris Simulation
Integrating Debris with Particle Effects
Debris Simulation Techniques:
We learn different techniques to create debris using rigid bodies and particles. We understand how we break objects, apply forces, and control motion to achieve realistic debris behavior in VFX simulations.
Optimizing Debris Simulation:
We learn how we optimize debris simulations by managing piece counts, simplifying geometry, and adjusting simulation settings to improve performance without losing visual quality.
Integrating Debris with Particle Effects:
We learn how we integrate debris simulations with particle effects such as dust, sparks, and smoke to enhance realism and create visually convincing destruction scenes.
week5
Voxels and Volumetric Pixels
Density, Temperature, and Velocity Fields
Pyro Simulation with Sparse Solver
Voxels and Volumetric Pixels:
We learn about voxels, also known as volumetric pixels, which are used to represent 3D data such as smoke and fire in Houdini. We understand how volumetric data is stored and visualized in VFX simulations.
Density, Temperature, and Velocity Fields:
We learn how density, temperature, and velocity fields control the behavior of smoke and fire. We use these fields to shape movement, intensity, and realism in pyro simulations.
Pyro Simulation with Sparse Solver:
We learn how to create and control fire and smoke simulations using the Pyro Sparse Solver, which allows us to simulate large-scale effects efficiently with optimized memory and performance.
Pyro Solver Techniques and Optimization
Controlling Flame Shape and Smoke Behavior
Leveraging Presets and Configurations for Pyro Effect
Rendering Smoke and Fire Simulations
Optimizing Simulation Data for Efficient Rendering
Leveraging Solaris and USD for Flexible Lighting and Rendering
Rendering Smoke and Fire Simulations:
We learn how we render smoke and fire simulations by applying shaders, lighting, and render settings to achieve realistic volumetric effects for VFX shots.
Optimizing Simulation Data for Efficient Rendering:
We learn how we optimize simulation data by reducing volume resolution, caching efficiently, and adjusting render settings to achieve faster render times without compromising visual quality.
Leveraging Solaris for Flexible Lighting and Rendering:
We learn how we use Solaris and USD workflows to manage scenes, apply lighting, and render VFX efficiently, allowing for better flexibility and integration in production pipelines.
week:
Vellum Cloth Simulation for Character Clothing
Procedural Clothing Creation Using Curves and Patches
Optimizing Cloth Simulation for Realistic Draping and Folds
Vellum Cloth Simulation for Character Clothing:
We learn how we use Vellum to simulate cloth for character clothing. We understand cloth constraints, collisions, and motion to create realistic fabric behavior for VFX shots.
Procedural Clothing Creation Using Curves and Patches:
We learn how we create procedural clothing using curves and patches, allowing us to generate flexible and editable garments suitable for simulation and iteration.
Optimizing Cloth Simulation for Realistic Draping and Folds
We learn how we optimize cloth simulations by adjusting constraints, resolution, and solver settings to achieve natural draping, folds, and believable cloth movement.
test with velum cloths :
week
Simulating Particle Dynamics in Houdini
Controlling Particle Behavior with Streams and Attributes
Simulating Particle Dynamics in Houdini:
We learn how we simulate particle dynamics in Houdini by using forces, emitters, and solvers to create natural motion for VFX effects such as sparks, dust, and energy.
Controlling Particle Behavior with Streams and Attributes:
We learn how we control particle behavior using particle streams and attributes. We modify attributes like velocity, life, size, and color to shape particle motion and appearance.
Visualizing Particle Trails and Geometry:
We learn how we visualize particles by generating trails and geometry, allowing us to enhance motion clarity and convert particles into renderable VFX elements
Fluid Implicit Particles: Combining Volumes and Particles
Controlling Fluid Behavior with Viscosity and Velocity
Fluid Implicit Particles: Combining Volumes and Particles:
We learn how Fluid Implicit Particles (FLIP) combine particles and volumes to simulate realistic liquid behavior, allowing us to create detailed and stable fluid simulations in Houdini.
Controlling Fluid Behavior with Viscosity and Velocity:
We learn how we control fluid behavior by adjusting viscosity and velocity parameters to create different liquid types such as water, mud, or honey in VFX simulations.
Optimizing Fluid Surfacing for Detailed Splashes:
We learn how we optimize fluid surfacing by refining particle resolution, surface settings, and meshing controls to achieve clean, detailed splashes and efficient rendering.
week
Fluid Implicit Particles: Combining Volumes and Particles
Controlling Fluid Behavior with Viscosity and Velocity
Fluid Implicit Particles: Combining Volumes and Particles:
We learn how FLIP (Fluid Implicit Particles) uses both particles and volumes to create stable and realistic liquid simulations such as water splashes and flowing fluids in VFX.
Controlling Fluid Behavior with Viscosity and Velocity:
We learn how we control fluid motion by adjusting viscosity and velocity to simulate different liquid types, from fast-moving water to thick fluids like mud or syrup.
Optimizing Fluid Surfacing for Detailed Splashes:
We learn how we optimize fluid meshing and surfacing settings to produce clean, detailed splashes while maintaining efficient simulation and rendering performance.
Grains Simulate Sand, Dust, and Snow
Vellum Grains Offer More Control Over Constraints
Grains Simulate Sand, Dust, and Snow:
We learn how we use grain simulations to create natural effects such as sand, dust, and snow, commonly used in VFX for environmental and destruction scenes.
Vellum Grains Offer More Control Over Constraints:
We learn how Vellum grains provide greater control over constraints like stiffness, friction, and cohesion to achieve realistic granular behavior.
Attributes and Ramps Customize Clumping and Breaking:
We learn how we use attributes and ramps to control clumping, breaking, and variation in grain simulations, allowing for more detailed and artistic control.
Creating Digital Assets in Houdini
Packaging Houdini Setups as Reusable Tools
Creating Digital Assets in Houdini:
We learn how we create Houdini Digital Assets (HDAs) to turn node networks into reusable tools for VFX workflows.
Packaging Houdini Setups as Reusable Tools:
We learn how we package complex Houdini setups into clean, reusable assets that improve efficiency and consistency in production.
Customizing the Interface and Behavior of Digital Assets:
We learn how we customize the interface and behavior of digital assets by exposing parameters, organizing controls, and defining asset functionality.
Final Project Explanation – Gargoyle Destruction Shot (Houdini / Karma)
Project Overview
For this project, I created a cinematic shot of a stone gargoyle statue undergoing structural damage and destruction in a dramatic, atmospheric environment.
The project was developed in Houdini, using Solaris and Karma for lighting and rendering.
The focus of the work was on FX simulation, look development, lighting, camera movement, and render optimisation, while working under realistic technical constraints.
Cinematic Direction & Destruction Control
In addition to the technical simulation, I approached the destruction from a cinematic director’s perspective rather than allowing the building to collapse randomly.
Key creative decisions included:
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Controlling where and when destruction occurs, rather than using uniform breakage
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Directing debris to support the camera framing and silhouette
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Preserving important visual areas of the gargoyle to maintain readability
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Allowing certain sections to break earlier while others remain intact for dramatic timing
This approach allowed the destruction to:
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Feel intentional and story-driven
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Support the camera movement and composition
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Enhance scale and impact rather than overwhelm the shot
By treating the destruction as a directed cinematic event, the final result prioritises visual storytelling over pure physical accuracy.
Geometry & Simulation
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The gargoyle statue was imported as geometry and prepared for RBD destruction.
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The destruction was simulated using Houdini’s rigid body tools and exported using an OUT_RBD_SIM node.
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The simulation was tested and refined to maintain readable break patterns and believable scale.
Challenges & Fixes:
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Initial simulations were heavy and slow to iterate.
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Geometry density and solver settings were adjusted to balance detail and performance.
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Proper caching and output management were used to stabilise playback and rendering.
Materials & Shading
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The gargoyle uses a stone material developed to appear heavy, aged, and weathered.
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Early versions were overly reflective and produced unwanted sparkle.
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This was fixed by:
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Increasing surface roughness
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Reducing specular intensity
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Adjusting the material response to light to better match the stone
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The final material reads clearly as matte stone and supports the dramatic lighting.
Lighting & Atmosphere
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A moody blue-to-red lighting contrast was used to create depth and silhouette.
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Volumetric fog was introduced to enhance scale and atmosphere.
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Lighting was carefully balanced so the statue remained readable even in low-light conditions.
Camera & Cinematography
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A slow camera pan was added to introduce movement and cinematic flow.
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Camera framing was adjusted to emphasise the gargoyle’s scale and presence.
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Depth of field and motion blur were tested and evaluated for realism.
Rain (Design Decision)
A rain simulation was created and tested during development.
However, due to the high render cost of combining rain, volumetric fog, motion blur, and destruction at final resolution, the rain was removed from the final render to ensure stability, clarity, and completion before the deadline.
This decision reflects a real-world production choice, prioritising:
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Visual clarity
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Render reliability
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Successful final delivery
Rendering & Optimization
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Rendered using Karma
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Resolution and sampling were optimised for performance
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Heavy features such as caustics were avoided
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EXR image sequences were used for stable output
These optimisations allowed the final sequence to be completed within time constraints.
Final Outcome
The final shot communicates:
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The scale and weight of the gargoyle
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Controlled destruction
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A cinematic atmosphere and lighting style
The project demonstrates:
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Understanding of Houdini FX workflows
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Technical problem solving
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Artistic decision-making under constraints
Self-Reflection
This project emphasised the importance of balancing ambition with practicality.
Testing, optimisation, and creative compromise were essential to completing the work successfully.
With additional time, future improvements could include:
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Reintroducing rain with optimised passes
Final Note
This submission represents both my technical development and creative intent during the project.
*note (please change the quality to full hd or 4k before you watch it )