Rotation animation

Animated visualization of grid rotation

Introduction

Grids can be rotated around the origin.

Some more info on rotations is in example rotated_grids.py.

In this example, an animation is created where the grid rotates around the origin. The grid is centered around zero and rotated a little more every frame. Since hexagonal grids have a six-fold symmetry, we only have to animate from 0-60 and loop it. It will look like a continuous rotation. Every frame, a new grid is created that is centered around 0,0 and rotated two degrees more than the previous frame.

Once Loop Reflect

import matplotlib.pyplot as plt
import numpy
from matplotlib.animation import FuncAnimation

from gridkit import HexGrid
from gridkit.doc_utils import plot_polygons

# Initialize
grid = HexGrid(size=1, rotation=0).anchor([0, 0])
center_id = grid.cell_at_point([0, 0])
ids = grid.neighbours(center_id, depth=4)
distance = numpy.linalg.norm(grid.centroid(ids) - grid.centroid(center_id), axis=1)


def update_frame(rotation):
    ax.clear()
    ax.scatter(0, 0)
    grid.rotation = rotation
    geoms = grid.to_shapely(ids, as_multipolygon=True)
    im = plot_polygons(geoms.geoms, colors=distance, fill=True, ax=ax)
    ax.set_title(f"Rotation: {rotation} degrees")
    ax.set_xlim(-5, 5)
    ax.set_ylim(-5, 5)
    ax.set_axis_off()


# Create animation
fig, ax = plt.subplots()
ax.set_aspect("equal")
anim = FuncAnimation(
    fig, update_frame, frames=range(0, 60, 2), repeat=True, interval=50
)
plt.show()