Flooding Stairs
Title: Flooding Stairs
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Programs: Houdini
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Modeled: Semi-Procedural Houdini
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SIM: Houdini
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Lighting: Houdini
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Texture: Houdini
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Rendering: Mantra
Description:
An exploration into Houdini 18 FLIP fluids, in order to replicate a real-life reference as closely as possible.
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As of (3/27/20) is the reference video, animation, still frame render, flipbooks, and Houdini breakdowns.
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Render
Animation
Particle Tank Prep
Reference
Original Video found at:
https://twitter.com/jbguild/status/985877422884220928
FLIP Tests
Particle Tank Prep
Flip tank settings
Particle Tank Prep
Unwanted particles are grouped by the collision volume and then blasted. This is done to make the SIM more efficient, as well as prevent particles being born inside collision geometry.
Bounding object to ensure particles don't fall out of sim area.
Particle Source
A VDB, Surface Distance Field is created from the stairs, transformed and then intersected using VDB Combine to scatter points inside.
Particle Source
Particles are scattered inside the volume. Afterward, their position is moved using various noise functions.
Particle Source
Any points moved inside the stairs are grouped and deleted.
Particle Source
Noise functions and various ramps are used to remove points at semi-random locations. As well as create a velocity vector.
Particle Source Top
The same process is repeated for the top source.
Particle Source Top Animated
Collision
Collision geometry
FLIP Forces
All forces
FLIP Forces
A box is created to define a region, while a mountain node is animated to create an undulating shape. Points are scattered inside the box, and then point vop is used to remove points and create velocity vector.
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Finally the points are rasterized using volume rasterize attribute.
FLIP Forces
Ground force
FLIP Forces
Middle Stair Force
FLIP Forces
Top Stair Force
FLIP Forces
Edge Sink Force
FLIP SIM
FLIP SIM Network
FLIP SIM Settings
All settings for FLIP SIM
FLIP SIM Flipbook
File Version: 133
Core Fluid Mesh
What the Core FLIP fluid looks like after being passed through a Particle Fluid Surface node
White Water Prep
The compressed fluid cache is passed to the White Water Source node to generate the needed volume.
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The fluid compress created issues where part of the volume was packed below the surface of the stairs. When passed to the whitewater sim particles would jump from below the stair plane.
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This was fixed by using the stairs as a second whitewater source and vdb combine (Subtract) from the fluid cache.
White Water Prep
White Water Prep: Emission
White Water Prep: Curvature
White Water Prep: Acceleration
White Water Prep: Vorticity
White Water Prep: Extra Volumes
White Water SIM
POP Drag and POP Wind are used to break up the evenness of the SIM. It was found out that the new "Clump Density" controls in the Foam tab is needed to be either turned off or set to much higher neighborhood values to allow fine detail to persist.
White Water SIM
Settings
White Water SIM
Settings
White Water Flipbook
White Water Render Prep
Group separation and volume creation
Fluid Core Shader
Fluid Volume Shader
Foam Shader
White Water Shader
Spray Shader
Railing Shader
Sign Shader
Signpost Shader
Stairs Shader
Ticket Machine Shader
Wall Shader
Wall Moulding Shader
