RigidWorld

Manim-physics’ Space and SpaceScene. RigidMotion::new(bodies, gravity, seconds) runs rapier once at 60 steps a second, in the video’s constructor. The same bodies give the same motion every time (enhanced-determinism). A Body is Body::circle, Body::rect, Body::polygon (the convex hull of its points) or Body::wall(a, b, thickness), which is fixed. It is set up with velocity, spin, angle, fixed, restitution, friction, density and color. poses(t) gives every body’s Pose (x, y, and an angle that counts whole turns). RigidWorld draws the bodies, filled and outlined, with a radius on circles that shows them turning. Its draw closure gets a BodyView (index, center in pixels, rotation in degrees for SVG rotate(), pixels per unit) and returns its own drawing, or None to keep the default. Rapier adds about 2 MB to an editor bridge built with physics. Gallery scene: RigidWorld.

RigidWorld 4 sPlayUnmuteCopy render command

use fframes_kit::prelude::*;

struct Video {
    world: RigidMotion,
}

impl Video {
    fn new() -> Self {
        let bodies = vec![
            Body::wall((-6.0, -3.0), (6.0, -3.0), 0.3),
            Body::circle(-2.0, 2.0, 0.4).velocity(1.5, 0.0).restitution(0.8),
            Body::rect(1.0, 1.0, 1.0, 0.6).angle(0.4),
        ];
        Self {
            world: RigidMotion::new(bodies, (0.0, -9.81), 5.0),
        }
    }

    fn figure<'a>(&'a self, ui: &mut Ui<'a, '_, '_>) -> Svgr<'a> {
        ui.show(RigidWorld {
            motion: Some(&self.world),
            ..ui.defaults()
        })
    }
}

API

Components are plain structs. Set the fields you need and fill the rest with ..ui.defaults(): the defaults below come from the current theme (theme. values are fields of Theme).

RigidWorld

Field	Type	Default	Description
motion	Option<&RigidMotion>	None	The simulated bodies to draw, built once in the video’s constructor; None draws nothing.
delay	f32	0.0	Seconds after the local start before the simulation starts to play.
time_scale	f32	1.0	Speed of the motion over local time; 2 runs twice as fast, 1 is real time.
draw	Option<DrawBody>	None	Draws a body in your own way: a closure given its BodyView that returns the picture, or None to leave it to the default shape.
fill_color	Color	theme.colors.accent	Fill of a body that has no colour of its own.
fixed_color	Color	theme.colors.muted	Fill of fixed bodies such as walls.
stroke_color	Color	theme.colors.text	Colour of the outline, and of the radius that shows a circle turning.
stroke_width	f32	theme.stroke.thin	Outline width in pixels.
enter	Option<FadeIn>	None	Fade in at the start; None for none.
exit	Option<FadeOut>	None	Fade out before the end; None for none.

Feature physics · Source