Curve

The curve module provides a variety of easing and interpolation functions. Pass any of these to Entity.animate_* calls to control acceleration, bounce, elastic effects, and more.

Functions

Function	Signature	Description
`linear`	`linear(t)`	No easing, constant speed.
`in_sine`	`in_sine(t)`	Accelerating from zero velocity.
`out_sine`	`out_sine(t)`	Decelerating to zero velocity.
`in_out_sine`	`in_out_sine(t)`	Accelerate then decelerate.
`in_quad`	`in_quad(t)`	Quadratic easing in.
`out_quad`	`out_quad(t)`	Quadratic easing out.
`in_out_quad`	`in_out_quad(t)`	Quadratic easing in then out.
`in_cubic`	`in_cubic(t)`	Cubic easing in.
`out_cubic`	`out_cubic(t)`	Cubic easing out.
`in_out_cubic`	`in_out_cubic(t)`	Cubic easing in then out.
`in_quart`	`in_quart(t)`	Quartic easing in.
`out_quart`	`out_quart(t)`	Quartic easing out.
`in_out_quart`	`in_out_quart(t)`	Quartic easing in then out.
`in_quint`	`in_quint(t)`	Quintic easing in.
`out_quint`	`out_quint(t)`	Quintic easing out.
`in_out_quint`	`in_out_quint(t)`	Quintic easing in then out.
`in_expo`	`in_expo(t)`	Exponential easing in.
`out_expo`	`out_expo(t)`	Exponential easing out.
`in_out_expo`	`in_out_expo(t)`	Exponential easing in then out.
`in_circ`	`in_circ(t)`	Circular easing in.
`out_circ`	`out_circ(t)`	Circular easing out.
`in_out_circ`	`in_out_circ(t)`	Circular easing in then out.
`in_back`	`in_back(t, magnitude=1.70158)`	Overshooting cubic easing in.
`out_back`	`out_back(t, magnitude=1.70158)`	Overshooting cubic easing out.
`in_out_back`	`in_out_back(t, magnitude=1.70158)`	Overshooting cubic easing in then out.
`in_elastic`	`in_elastic(t, magnitude=0.7)`	Elastic bounce-in effect.
`out_elastic`	`out_elastic(t, magnitude=0.7)`	Elastic bounce-out effect.
`in_out_elastic`	`in_out_elastic(t, magnitude=0.65)`	Elastic bounce-in then out.
`out_bounce`	`out_bounce(t)`	Bounce out.
`in_bounce`	`in_bounce(t)`	Bounce in.
`in_out_bounce`	`in_out_bounce(t)`	Bounce in then out.
`zero`	`zero(t)`	Always returns 0.
`one`	`one(t)`	Always returns 1.
`combine`	`combine(curve_a, curve_b, split_at)`	Run `curve_a` until `split_at`, then `curve_b`.
`reverse`	`reverse(curve_function)`	Invert a curve’s progress.
`<e>_boomerang`	e.g. `in_quad_boomerang(t)`	Play `in_quad` then reverse it.

Example

from ursina import *
from ursina.curve import combine, reverse, linear, in_expo

app = Ursina()
camera.orthographic = True
camera.fov = 16
window.color = color.black

# Render custom curve
custom = combine(linear, reverse(in_expo), 0.25)
curve_line = Entity(
    model=Mesh(
        vertices=[Vec3(i/31, custom(i/31), 0) for i in range(32)],
        mode='line', thickness=2
    ),
    color=color.light_gray
)
Text(parent=curve_line, text='custom_curve', scale=8, color=color.gray, y=-0.1)

# Example usage in animation
e = Entity(model='cube')
e.animate_y(2, duration=1, curve=in_expo)

app.run()