animated_hillshade.py

from functools import partial

import datashader as ds
import numpy as np
from datashader.colors import Elevation
from datashader.transfer_functions import shade, stack

from xrspatial import bump, generate_terrain, hillshade, mean

W = 600
H = 400

cvs = ds.Canvas(plot_width=W, plot_height=H,
                x_range=(-20e6, 20e6),
                y_range=(-20e6, 20e6))

terrain = generate_terrain(canvas=cvs)


def heights(locations, src, src_range, height=20):
    num_bumps = locations.shape[0]
    out = np.zeros(num_bumps, dtype=np.uint16)
    for r in range(0, num_bumps):
        loc = locations[r]
        x = loc[0]
        y = loc[1]
        val = src[y, x]
        if val >= src_range[0] and val < src_range[1]:
            out[r] = height
    return out


T = 300000  # Number of trees to add per call
src = terrain.data
trees = bump(W, H, count=T, height_func=partial(heights, src=src,
             src_range=(1000, 1300), height=5))
trees += bump(W, H, count=T//2, height_func=partial(
        heights, src=src, src_range=(1300, 1700), height=20))
trees += bump(W, H, count=T//3, height_func=partial(
        heights, src=src, src_range=(1700, 2000), height=5))

tree_colorize = trees.copy()
tree_colorize.data[tree_colorize.data == 0] = np.nan

LAND_CONSTANT = 50.0

water = terrain.copy()
water.data = np.where(water.data > 0, LAND_CONSTANT, 0)
water = mean(water, passes=50, excludes=[LAND_CONSTANT])
water.data[water.data == LAND_CONSTANT] = np.nan


def create_map(azimuth):

    global cvs
    global terrain
    global water
    global trees

    img = stack(shade(terrain, cmap=Elevation, how='linear'),
                shade(water, cmap=['aqua', 'white']),
                shade(hillshade(terrain + trees, azimuth=azimuth),
                      cmap=['black', 'white'], how='linear', alpha=128),
                shade(tree_colorize, cmap='limegreen', how='linear')
                )

    print('image created')

    return img.to_pil()


def create_map2():

    global cvs
    global terrain
    global water
    global trees

    img = stack(shade(terrain, cmap=['black', 'white'], how='linear'))

    yield img.to_pil()

    img = stack(shade(terrain, cmap=Elevation, how='linear'))

    yield img.to_pil()

    img = stack(shade(terrain, cmap=Elevation, how='linear'),
                shade(hillshade(terrain, azimuth=210),
                      cmap=['black', 'white'], how='linear', alpha=128),
                )

    yield img.to_pil()

    img = stack(shade(terrain, cmap=Elevation, how='linear'),
                shade(water, cmap=['aqua', 'white']),
                shade(hillshade(terrain, azimuth=210),
                      cmap=['black', 'white'], how='linear', alpha=128),
                )

    yield img.to_pil()

    img = stack(shade(terrain, cmap=Elevation, how='linear'),
                shade(water, cmap=['aqua', 'white']),
                shade(hillshade(terrain + trees, azimuth=210),
                      cmap=['black', 'white'], how='linear', alpha=128),
                shade(tree_colorize, cmap='limegreen', how='linear')
                )

    yield img.to_pil()
    yield img.to_pil()
    yield img.to_pil()
    yield img.to_pil()


def gif1():

    images = []

    for i in np.linspace(0, 360, 6):
        images.append(create_map(int(i)))

    images[0].save('animated_hillshade.gif',
                   save_all=True, append_images=images[1:],
                   optimize=False, duration=5000, loop=0)


def gif2():

    images = list(create_map2())

    images[0].save('composite_map.gif',
                   save_all=True, append_images=images[1:],
                   optimize=False, duration=1000, loop=0)


gif2()