Transcript Digital Fashion Seminar

Computer Animation
Particle Collision
Lecture #4
Oh-young Song
Sejong University
During Simulation…
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Snapshots
During Simulation…
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■
Snapshots
Curved trajectories
treated as
piecewise linear
During Simulation…
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■
■
Snapshots
Curved trajectories
treated as
piecewise linear
Constant
throughout the
frame
During Simulation…
■
■
Snapshots
Things can happen
in-between
snapshots
During Simulation…
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■
Snapshots
Things mostly
happen in-between
snapshots
Collision!
Bouncing off the Wall
Point-plane collisions
■ Adding it to particle simulator!
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Collision Detection
■ Collision Response
■ Contact
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Collision Detection
Signed Distance
Velocity Components
■
Normal & Tangential
Collision Response
Collision Response
Damping factor = 0.8
If penalty method…
Contact
■
Contact Condition
Contact Force
Do we’ve done it all?
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■
Yes, in case of particles…
But there are many collision
algorithms for rigid bodies.
● Search Sphere bounding volume, OBB,
AABB, k-DOP, GJK, …
Caution!
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Tunneling
Caution!
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Tunneling
Caution!
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Tunneling
Caution!
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Tunneling
Caution!
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Fast-moving particles
tunnel more easily
How can we solve this?
Caution!
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Fast-moving particles
tunnel more easily
Restriction Speed/Time?
A Solution
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Swept Particle
A Solution
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Swept Particle
Next…
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Implicit Method