# http://pyrocko.org - GPLv3
#
# The Pyrocko Developers, 21st Century
# ---|P------/S----------~Lg----------
'''
Topography tile data model.
'''
import math
import numpy as num
import scipy.signal
from pyrocko.orthodrome import positive_region
km = 1e3
class OutOfBounds(Exception):
pass
[docs]class Tile(object):
'''
2D array of data values which are regularly gridded in lon/lat.
'''
def __init__(self, xmin, ymin, dx, dy, data):
self.xmin = float(xmin)
self.ymin = float(ymin)
self.dx = float(dx)
self.dy = float(dy)
self.data = data
self._set_maxes()
def _set_maxes(self):
self.ny, self.nx = self.data.shape
self.xmax = self.xmin + (self.nx-1) * self.dx
self.ymax = self.ymin + (self.ny-1) * self.dy
def x(self):
return self.xmin + num.arange(self.nx) * self.dx
def y(self):
return self.ymin + num.arange(self.ny) * self.dy
def decimate(self, ndeci):
assert ndeci % 2 == 0
kernel = num.ones((ndeci+1, ndeci+1))
kernel /= num.sum(kernel)
data = scipy.signal.convolve2d(
self.data.astype(float), kernel, mode='valid')
self.data = data[::ndeci, ::ndeci].astype(self.data.dtype)
self.xmin += ndeci/2
self.ymin += ndeci/2
self.dx *= ndeci
self.dy *= ndeci
self._set_maxes()
def yextend_with_repeat(self, ymin, ymax):
assert ymax >= self.ymax
assert ymin <= self.ymin
nlo = int(round((self.ymin - ymin) / self.dy))
nhi = int(round((ymax - self.ymax) / self.dy))
nx, ny = self.nx, self.ny
data = num.zeros((ny+nlo+nhi, nx), dtype=self.data.dtype)
data[:nlo, :] = self.data[nlo, :]
data[nlo:nlo+ny, :] = self.data
data[nlo+ny:, :] = self.data[-1, :]
self.ymin = ymin
self.data = data
self._set_maxes()
def get(self, x, y):
ix = int(round((x - self.xmin) / self.dx))
iy = int(round((y - self.ymin) / self.dy))
if 0 <= ix < self.nx and 0 <= iy < self.ny:
return self.data[iy, ix]
else:
raise OutOfBounds()
[docs] @classmethod
def from_grd(cls, path):
'''Load from GMT .grd'''
from pyrocko.plot import gmtpy
lon, lat, z = gmtpy.loadgrd(path)
return cls(lon[0], lat[0], lon[1] - lon[0], lat[1] - lat[0], z)
def multiple_of(x, dx, eps=1e-5):
return abs(int(round(x / dx))*dx - x) < dx * eps
def combine(tiles, region=None):
if not tiles:
return None
dx = tiles[0].dx
dy = tiles[0].dy
dtype = tiles[0].data.dtype
assert all(t.dx == dx for t in tiles)
assert all(t.dy == dy for t in tiles)
assert all(t.data.dtype == dtype for t in tiles)
assert all(multiple_of(t.xmin, dx) for t in tiles)
assert all(multiple_of(t.ymin, dy) for t in tiles)
if region is None:
xmin = min(t.xmin for t in tiles)
xmax = max(t.xmax for t in tiles)
ymin = min(t.ymin for t in tiles)
ymax = max(t.ymax for t in tiles)
else:
xmin, xmax, ymin, ymax = positive_region(region)
if not multiple_of(xmin, dx):
xmin = math.floor(xmin / dx) * dx
if not multiple_of(xmax, dx):
xmax = math.ceil(xmax / dx) * dx
if not multiple_of(ymin, dy):
ymin = math.floor(ymin / dy) * dy
if not multiple_of(ymax, dy):
ymax = math.ceil(ymax / dy) * dy
nx = int(round((xmax - xmin) / dx)) + 1
ny = int(round((ymax - ymin) / dy)) + 1
data = num.zeros((ny, nx), dtype=dtype)
data[:, :] = 0
for t in tiles:
for txmin in (t.xmin, t.xmin + 360.):
ix = int(round((txmin - xmin) / dx))
iy = int(round((t.ymin - ymin) / dy))
ixlo = max(ix, 0)
ixhi = min(ix+t.nx, nx)
iylo = max(iy, 0)
iyhi = min(iy+t.ny, ny)
jxlo = ixlo-ix
jxhi = jxlo + max(0, ixhi - ixlo)
jylo = iylo-iy
jyhi = jylo + max(0, iyhi - iylo)
if iyhi > iylo and ixhi > ixlo:
data[iylo:iyhi, ixlo:ixhi] = t.data[jylo:jyhi, jxlo:jxhi]
if not num.any(num.isfinite(data)):
return None
return Tile(xmin, ymin, dx, dy, data)
[docs]def tile_export(tle, path, format='stl', exaggeration=3., socket_scale=1.,
scale=100):
'''Export DEM to 3D printable formats'''
import trimesh
from pyrocko import geometry
from pyrocko.cake import earthradius
x = tle.x()
x = x - x.min()
y = tle.y()
y = y - y.min()
data = tle.data * exaggeration
vertices, faces = geometry.topo_to_mesh(
y, x, data, earthradius)
vertices[:, 0] -= vertices[:, 0].min()
nlat = y.size
nlon = x.size
socket_level = -vertices[:, 0].max() * socket_scale
nvertices = vertices.shape[0]
south_indices = num.arange(0, nlon)
north_indices = num.arange(nvertices - nlon, nvertices)
east_indices = num.arange(0, nlat) * nlon
west_indices = num.arange(0, nlat) * nlon + nlon - 1
north_indices = north_indices[::-1]
east_indices = east_indices[::-1]
socket_bottom_faces = []
for border_indices in [north_indices, east_indices,
south_indices, west_indices]:
nvertices = vertices.shape[0]
nfaces = border_indices.size - 1
socket_vertices = vertices[border_indices.astype(int)].copy()
socket_vertices[:, 0] = socket_level
socket_faces = num.empty((nfaces, 4), dtype=int)
for iface in range(nfaces):
socket_faces[iface, 0] = iface + nvertices
socket_faces[iface, 1] = iface + nvertices + 1
socket_faces[iface, 2] = border_indices[iface+1]
socket_faces[iface, 3] = border_indices[iface]
vertices = num.vstack((vertices, socket_vertices))
faces = num.vstack((faces, socket_faces))
socket_bottom_faces.append(vertices.shape[0] - nfaces)
faces = num.vstack((faces, socket_bottom_faces[::-1]))
mesh = trimesh.Trimesh(
vertices, faces)
mesh.fix_normals()
mesh.fill_holes()
mesh.apply_scale(scale)
with open(path, 'wb') as f:
mesh.export(f, file_type=format)
return mesh
