An interactive, GPU-accelerated particle field. Particles rest on a drifting grid of "home" positions, lift into a glowing ring around the pointer, orbit it with a wave distortion, and burst outward on click. When the pointer is idle the ring wanders on its own.

Rendering uses Win2D (CanvasAnimatedControl), created when the control loads and disposed when it unloads.

Quick start

<dev:Antigravity Height="480" />

<dev:Antigravity
    Height="480"
    ColorMode="Conic"
    ParticleCount="1500"
    ParticleShape="Capsule"
    MagnetRadius="170"
    RingRadius="120" />

Field.ParticleShape = AntigravityParticleShape.Sphere;
Field.ColorMode = AntigravityColorMode.Radial;
Field.Replay();

The control fills its parent. Give it a Height (or place it in a star-sized row) so it has something to draw into.

Interaction

Input	Effect
Move pointer	Ring follows the pointer
Hold pointer down	Ring contracts and the orbit speeds up
Release pointer	Particles near the ring burst outward (requires ClickBurst)
Pointer idle for 2 s	Ring drifts on its own (requires AutoAnimate)

Set IsInteractive="False" to ignore the pointer entirely.

Properties

Particles

Property	Type	Default	Description
ParticleCount	int	1200	Number of particles. Clamped to 0–5000. Changing it at runtime adds or removes particles without restarting.
ParticleSize	double	0.9	Base particle size multiplier. Minimum 0.05.
ParticleShape	AntigravityParticleShape	Capsule	Shape drawn for each particle.
ParticleVariance	double	1	Strength of the per-particle size pulse. Clamped to 0–1.
PulseSpeed	double	3	Speed of the size pulse.
DepthFactor	double	1	How strongly the fake depth changes particle size and opacity. 0 flattens the field.
Ambient	double	0.25	Opacity of particles outside the ring. Particles inside the ring are fully opaque. Clamped to 0–1.

Ring and motion

Property	Type	Default	Description
MagnetRadius	double	170	Distance from the pointer within which particles are pulled into the ring. Minimum 1.
RingRadius	double	120	Radius of the ring. Minimum 0.
FieldStrength	double	10	How tightly particles hug the ring. Lower values spread them into a thicker band.
LerpSpeed	double	0.05	How quickly the ring follows its target and how stiffly particles spring. Clamped to 0.005–1. The particle spring stiffness is capped at 0.5 for stability.
RotationSpeed	double	0	Orbit speed of the ring in radians per second. Negative values reverse the direction.
WaveSpeed	double	0.4	Speed of the wave distortion on the ring.
WaveAmplitude	double	1	Strength of the wave distortion.
WaveCount	int	3	Number of waves around the ring.

Color

Property	Type	Default	Description
Palette	Brush	theme resource AntigravityPaletteBrush	Colors used for the particles. See Palette.
ColorMode	AntigravityColorMode	Conic	How colors are assigned.
ColorSpeed	double	0.05	Speed at which the Conic palette rotates.

Behavior

Property	Type	Default	Description
AutoAnimate	bool	true	Moves the ring automatically when the pointer is idle or absent.
IsInteractive	bool	true	Enables pointer tracking.
ClickBurst	bool	true	Enables the press-and-release burst.
Intro	bool	true	Particles rise into place when the field is built.
IsPaused	bool	false	Pauses updates and rendering. The control also pauses automatically while Visibility is Collapsed.

Methods

Method	Description
Replay()	Rebuilds the particle field and replays the intro.

Enums

AntigravityParticleShape

Capsule, Sphere, Box, Tetrahedron

Capsule particles stretch along their direction of travel. The other shapes spin.

AntigravityColorMode

Value	Description
Conic	Color follows the angle around the ring and rotates over time. The palette wraps back to its first color.
Radial	Color follows the distance from the ring.
Random	Each particle keeps a fixed random position on the palette.

Palette

Palette accepts any GradientBrush or SolidColorBrush. Gradient stops are sorted by offset and sampled into a 256-entry lookup table.

<dev:Antigravity>
    <dev:Antigravity.Palette>
        <LinearGradientBrush>
            <GradientStop Offset="0" Color="#00C2FF" />
            <GradientStop Offset="0.5" Color="#7A5CFF" />
            <GradientStop Offset="1" Color="#FF5C9D" />
        </LinearGradientBrush>
    </dev:Antigravity.Palette>
</dev:Antigravity>

• If Palette is null, the control's Foreground is used.
• Stop alpha is ignored. Opacity is controlled by Ambient and DepthFactor.
• Brushes that are neither gradient nor solid (acrylic, image) fall back to white.
• Changes to a SolidColorBrush.Color, or to the Color or Offset of an existing gradient stop, update the control live. Adding or removing stops on a live brush is not detected; assign a new brush to Palette instead.
• The default palette is defined per theme (Default, Light, HighContrast) by the AntigravityPaletteBrush resource.

Customizing the default palette

Override the resource in your app resources:

<ResourceDictionary.ThemeDictionaries>
    <ResourceDictionary x:Key="Default">
        <LinearGradientBrush x:Key="AntigravityPaletteBrush" StartPoint="0,0" EndPoint="1,0">
            <GradientStop Offset="0" Color="#00C2FF" />
            <GradientStop Offset="1" Color="#FF5C9D" />
        </LinearGradientBrush>
    </ResourceDictionary>
</ResourceDictionary.ThemeDictionaries>

Performance notes

• Cost scales with ParticleCount. A few thousand particles is fine on most hardware; the cap is 5000.
• Tetrahedron draws three filled geometries per particle and is the most expensive shape.
• Set IsPaused="True" when the field is off-screen but still visible in the tree, for example behind another page in a Frame cache.

Lifecycle

The canvas is created on Loaded and disposed on Unloaded. Navigating away and back rebuilds the field, so the intro plays again. Set Intro="False" to start with the particles already in place.

Demo

you can run demo and see this feature.