blender-addons/ant_landscape/eroder.py
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2023-06-15 16:54:05 +10:00

614 lines
24 KiB
Python

# SPDX-FileCopyrightText: 2017-2022 Blender Foundation
#
# SPDX-License-Identifier: GPL-2.0-or-later
from time import time
import unittest
import sys
import os
from random import random as rand, shuffle
import numpy as np
numexpr_available = False
def getmemsize():
return 0.0
def getptime():
return time()
class Grid:
def __init__(self, size=10, dtype=np.single):
self.center = np.zeros([size, size], dtype)
self.water = None
self.sediment = None
self.scour = None
self.flowrate = None
self.sedimentpct = None
self.sedimentpct = None
self.capacity = None
self.avalanced = None
self.minx = None
self.miny = None
self.maxx = None
self.maxy = None
self.zscale = 1
self.maxrss = 0.0
self.sequence = [0, 1, 2, 3]
self.watermax = 1.0
self.flowratemax = 1.0
self.scourmax = 1.0
self.sedmax = 1.0
self.scourmin = 1.0
def init_water_and_sediment(self):
if self.water is None:
self.water = np.zeros(self.center.shape, dtype=np.single)
if self.sediment is None:
self.sediment = np.zeros(self.center.shape, dtype=np.single)
if self.scour is None:
self.scour = np.zeros(self.center.shape, dtype=np.single)
if self.flowrate is None:
self.flowrate = np.zeros(self.center.shape, dtype=np.single)
if self.sedimentpct is None:
self.sedimentpct = np.zeros(self.center.shape, dtype=np.single)
if self.capacity is None:
self.capacity = np.zeros(self.center.shape, dtype=np.single)
if self.avalanced is None:
self.avalanced = np.zeros(self.center.shape, dtype=np.single)
def __str__(self):
return ''.join(self.__str_iter__(fmt="%.3f"))
def __str_iter__(self, fmt):
for row in self.center[::]:
values = []
for v in row:
values.append(fmt % v)
yield ' '.join(values) + '\n'
@staticmethod
def fromFile(filename):
if filename == '-':
filename = sys.stdin
g = Grid()
g.center = np.loadtxt(filename, np.single)
return g
def toFile(self, filename, fmt="%.3f"):
if filename == '-':
filename = sys.stdout.fileno()
with open(filename, "w") as f:
for line in self.__str_iter__(fmt):
f.write(line)
def raw(self, format="%.3f"):
fstr = format + " " + format + " " + format + " "
a = self.center / self.zscale
minx = 0.0 if self.minx is None else self.minx
miny = 0.0 if self.miny is None else self.miny
maxx = 1.0 if self.maxx is None else self.maxx
maxy = 1.0 if self.maxy is None else self.maxy
dx = (maxx - minx) / (a.shape[0] - 1)
dy = (maxy - miny) / (a.shape[1] - 1)
for row in range(a.shape[0] - 1):
row0 = miny + row * dy
row1 = row0 + dy
for col in range(a.shape[1] - 1):
col0 = minx + col * dx
col1 = col0 + dx
yield (fstr % (row0, col0, a[row][col]) +
fstr % (row0, col1, a[row][col + 1]) +
fstr % (row1, col0, a[row + 1][col]) + "\n")
yield (fstr % (row0, col1, a[row][col + 1]) +
fstr % (row1, col0, a[row + 1][col]) +
fstr % (row1, col1, a[row + 1][col + 1]) + "\n")
def toRaw(self, filename, infomap=None):
with open(filename if type(filename) == str else sys.stdout.fileno(), "w") as f:
f.writelines(self.raw())
if infomap:
with open(os.path.splitext(filename)[0] + ".inf" if type(filename) == str else sys.stdout.fileno(), "w") as f:
f.writelines("\n".join("%-15s: %s" % t for t in sorted(infomap.items())))
@staticmethod
def fromRaw(filename):
"""initialize a grid from a Blender .raw file.
currently supports just rectangular grids of all triangles
"""
g = Grid.fromFile(filename)
# we assume tris and an axis aligned grid
g.center = np.reshape(g.center, (-1, 3))
g._sort()
return g
def _sort(self, expfact):
# keep unique vertices only by creating a set and sort first on x then on y coordinate
# using rather slow python sort but couldn't wrap my head around np.lexsort
verts = sorted(list({tuple(t) for t in self.center[::]}))
x = set(c[0] for c in verts)
y = set(c[1] for c in verts)
nx = len(x)
ny = len(y)
self.minx = min(x)
self.maxx = max(x)
self.miny = min(y)
self.maxy = max(y)
xscale = (self.maxx - self.minx) / (nx - 1)
yscale = (self.maxy - self.miny) / (ny - 1)
# note: a purely flat plane cannot be scaled
if (yscale != 0.0) and (abs(xscale / yscale) - 1.0 > 1e-3):
raise ValueError("Mesh spacing not square %d x %d %.4f x %4.f" % (nx, ny, xscale, yscale))
self.zscale = 1.0
if abs(yscale) > 1e-6:
self.zscale = 1.0 / yscale
# keep just the z-values and null any offset
# we might catch a reshape error that will occur if nx*ny != # of vertices
# (if we are not dealing with a heightfield but with a mesh with duplicate
# x,y coords, like an axis aligned cube
self.center = np.array([c[2] for c in verts], dtype=np.single).reshape(nx, ny)
self.center = (self.center - np.amin(self.center)) * self.zscale
if self.rainmap is not None:
rmscale = np.max(self.center)
self.rainmap = expfact + (1 - expfact) * (self.center / rmscale)
@staticmethod
def fromBlenderMesh(me, vg, expfact):
g = Grid()
g.center = np.asarray(list(tuple(v.co) for v in me.vertices), dtype=np.single)
g.rainmap = None
if vg is not None:
for v in me.vertices:
vg.add([v.index], 0.0, 'ADD')
g.rainmap = np.asarray(list((v.co[0], v.co[1], vg.weight(v.index)) for v in me.vertices), dtype=np.single)
g._sort(expfact)
return g
def setrainmap(self, rainmap):
self.rainmap = rainmap
def _verts(self, surface):
a = surface / self.zscale
minx = 0.0 if self.minx is None else self.minx
miny = 0.0 if self.miny is None else self.miny
maxx = 1.0 if self.maxx is None else self.maxx
maxy = 1.0 if self.maxy is None else self.maxy
dx = (maxx - minx) / (a.shape[0] - 1)
dy = (maxy - miny) / (a.shape[1] - 1)
for row in range(a.shape[0]):
row0 = miny + row * dy
for col in range(a.shape[1]):
col0 = minx + col * dx
yield (row0, col0, a[row][col])
def _faces(self):
nrow, ncol = self.center.shape
for row in range(nrow - 1):
for col in range(ncol - 1):
vi = row * ncol + col
yield (vi, vi + ncol, vi + 1)
yield (vi + 1, vi + ncol, vi + ncol + 1)
def toBlenderMesh(self, me):
# pass me as argument so that we don't need to import bpy and create a dependency
# the docs state that from_pydata takes iterators as arguments but it will
# fail with generators because it does len(arg)
me.from_pydata(list(self._verts(self.center)), [], list(self._faces()))
def toWaterMesh(self, me):
# pass me as argument so that we don't need to import bpy and create a dependency
# the docs state that from_pydata takes iterators as arguments but it will
# fail with generators because it does len(arg)
me.from_pydata(list(self._verts(self.water)), [], list(self._faces()))
def peak(self, value=1):
nx, ny = self.center.shape
self.center[int(nx / 2), int(ny / 2)] += value
def shelf(self, value=1):
nx, ny = self.center.shape
self.center[:nx / 2] += value
def mesa(self, value=1):
nx, ny = self.center.shape
self.center[nx / 4:3 * nx / 4, ny / 4:3 * ny / 4] += value
def random(self, value=1):
self.center += np.random.random_sample(self.center.shape) * value
def neighborgrid(self):
self.up = np.roll(self.center, -1, 0)
self.down = np.roll(self.center, 1, 0)
self.left = np.roll(self.center, -1, 1)
self.right = np.roll(self.center, 1, 1)
def zeroedge(self, quantity=None):
c = self.center if quantity is None else quantity
c[0, :] = 0
c[-1, :] = 0
c[:, 0] = 0
c[:, -1] = 0
def diffuse(self, Kd, IterDiffuse, numexpr):
self.zeroedge()
c = self.center[1:-1, 1:-1]
up = self.center[:-2, 1:-1]
down = self.center[2:, 1:-1]
left = self.center[1:-1, :-2]
right = self.center[1:-1, 2:]
if(numexpr and numexpr_available):
self.center[1:-1, 1:-1] = ne.evaluate('c + Kd * (up + down + left + right - 4.0 * c)')
else:
self.center[1:-1, 1:-1] = c + (Kd / IterDiffuse) * (up + down + left + right - 4.0 * c)
self.maxrss = max(getmemsize(), self.maxrss)
return self.center
def avalanche(self, delta, iterava, prob, numexpr):
self.zeroedge()
c = self.center[1:-1, 1:-1]
up = self.center[:-2, 1:-1]
down = self.center[2:, 1:-1]
left = self.center[1:-1, :-2]
right = self.center[1:-1, 2:]
where = np.where
if(numexpr and numexpr_available):
self.center[1:-1, 1:-1] = ne.evaluate('c + where((up -c) > delta ,(up -c -delta)/2, 0) \
+ where((down -c) > delta ,(down -c -delta)/2, 0) \
+ where((left -c) > delta ,(left -c -delta)/2, 0) \
+ where((right-c) > delta ,(right-c -delta)/2, 0) \
+ where((up -c) < -delta,(up -c +delta)/2, 0) \
+ where((down -c) < -delta,(down -c +delta)/2, 0) \
+ where((left -c) < -delta,(left -c +delta)/2, 0) \
+ where((right-c) < -delta,(right-c +delta)/2, 0)')
else:
sa = (
# incoming
where((up - c) > delta, (up - c - delta) / 2, 0)
+ where((down - c) > delta, (down - c - delta) / 2, 0)
+ where((left - c) > delta, (left - c - delta) / 2, 0)
+ where((right - c) > delta, (right - c - delta) / 2, 0)
# outgoing
+ where((up - c) < -delta, (up - c + delta) / 2, 0)
+ where((down - c) < -delta, (down - c + delta) / 2, 0)
+ where((left - c) < -delta, (left - c + delta) / 2, 0)
+ where((right - c) < -delta, (right - c + delta) / 2, 0)
)
randarray = np.random.randint(0, 100, sa.shape) * 0.01
sa = where(randarray < prob, sa, 0)
self.avalanced[1:-1, 1:-1] = self.avalanced[1:-1, 1:-1] + sa / iterava
self.center[1:-1, 1:-1] = c + sa / iterava
self.maxrss = max(getmemsize(), self.maxrss)
return self.center
def rain(self, amount=1, variance=0, userainmap=False):
self.water += (1.0 - np.random.random(self.water.shape) * variance) * \
(amount if ((self.rainmap is None) or (not userainmap)) else self.rainmap * amount)
def spring(self, amount, px, py, radius):
# px, py and radius are all fractions
nx, ny = self.center.shape
rx = max(int(nx * radius), 1)
ry = max(int(ny * radius), 1)
px = int(nx * px)
py = int(ny * py)
self.water[px - rx:px + rx + 1, py - ry:py + ry + 1] += amount
def river(self, Kc, Ks, Kdep, Ka, Kev, numexpr):
zeros = np.zeros
where = np.where
min = np.minimum
max = np.maximum
abs = np.absolute
arctan = np.arctan
sin = np.sin
center = (slice(1, -1, None), slice(1, -1, None))
up = (slice(None, -2, None), slice(1, -1, None))
down = (slice(2, None, None), slice(1, -1, None))
left = (slice(1, -1, None), slice(None, -2, None))
right = (slice(1, -1, None), slice(2, None, None))
water = self.water
rock = self.center
sediment = self.sediment
height = rock + water
# !! this gives a runtime warning for division by zero
verysmallnumber = 0.0000000001
water += verysmallnumber
sc = where(water > verysmallnumber, sediment / water, 0)
sdw = zeros(water[center].shape)
svdw = zeros(water[center].shape)
sds = zeros(water[center].shape)
angle = zeros(water[center].shape)
for d in (up, down, left, right):
if(numexpr and numexpr_available):
hdd = height[d]
hcc = height[center]
dw = ne.evaluate('hdd-hcc')
inflow = ne.evaluate('dw > 0')
wdd = water[d]
wcc = water[center]
# nested where() represent min() and max()
dw = ne.evaluate('where(inflow, where(wdd<dw, wdd, dw), where(-wcc>dw, -wcc, dw))/4.0')
sdw = ne.evaluate('sdw + dw')
scd = sc[d]
scc = sc[center]
rockd = rock[d]
rockc = rock[center]
sds = ne.evaluate('sds + dw * where(inflow, scd, scc)')
svdw = ne.evaluate('svdw + abs(dw)')
angle = ne.evaluate('angle + arctan(abs(rockd-rockc))')
else:
dw = (height[d] - height[center])
inflow = dw > 0
dw = where(inflow, min(water[d], dw), max(-water[center], dw)) / 4.0
sdw = sdw + dw
sds = sds + dw * where(inflow, sc[d], sc[center])
svdw = svdw + abs(dw)
angle = angle + np.arctan(abs(rock[d] - rock[center]))
if numexpr and numexpr_available:
wcc = water[center]
scc = sediment[center]
rcc = rock[center]
water[center] = ne.evaluate('wcc + sdw')
sediment[center] = ne.evaluate('scc + sds')
sc = ne.evaluate('where(wcc>0, scc/wcc, 2000*Kc)')
fKc = ne.evaluate('Kc*sin(Ka*angle)*svdw')
ds = ne.evaluate('where(sc > fKc, -Kd * scc, Ks * svdw)')
rock[center] = ne.evaluate('rcc - ds')
# there isn't really a bottom to the rock but negative values look ugly
rock[center] = ne.evaluate('where(rcc<0,0,rcc)')
sediment[center] = ne.evaluate('scc + ds')
else:
wcc = water[center]
scc = sediment[center]
rcc = rock[center]
water[center] = wcc * (1 - Kev) + sdw
sediment[center] = scc + sds
sc = where(wcc > 0, scc / wcc, 2 * Kc)
fKc = Kc * svdw
ds = where(fKc > sc, (fKc - sc) * Ks, (fKc - sc) * Kdep) * wcc
self.flowrate[center] = svdw
self.scour[center] = ds
self.sedimentpct[center] = sc
self.capacity[center] = fKc
sediment[center] = scc + ds + sds
def flow(self, Kc, Ks, Kz, Ka, numexpr):
zeros = np.zeros
where = np.where
min = np.minimum
max = np.maximum
abs = np.absolute
arctan = np.arctan
sin = np.sin
center = (slice(1, -1, None), slice(1, -1, None))
rock = self.center
ds = self.scour[center]
rcc = rock[center]
rock[center] = rcc - ds * Kz
# there isn't really a bottom to the rock but negative values look ugly
rock[center] = where(rcc < 0, 0, rcc)
def rivergeneration(
self,
rainamount,
rainvariance,
userainmap,
Kc,
Ks,
Kdep,
Ka,
Kev,
Kspring,
Kspringx,
Kspringy,
Kspringr,
numexpr,
):
self.init_water_and_sediment()
self.rain(rainamount, rainvariance, userainmap)
self.zeroedge(self.water)
self.zeroedge(self.sediment)
self.river(Kc, Ks, Kdep, Ka, Kev, numexpr)
self.watermax = np.max(self.water)
def fluvial_erosion(
self,
rainamount,
rainvariance,
userainmap,
Kc,
Ks,
Kdep,
Ka,
Kspring,
Kspringx,
Kspringy,
Kspringr,
numexpr,
):
self.flow(Kc, Ks, Kdep, Ka, numexpr)
self.flowratemax = np.max(self.flowrate)
self.scourmax = np.max(self.scour)
self.scourmin = np.min(self.scour)
self.sedmax = np.max(self.sediment)
def analyze(self):
self.neighborgrid()
# just looking at up and left to avoid needless double calculations
slopes = np.concatenate((np.abs(self.left - self.center), np.abs(self.up - self.center)))
return '\n'.join(["%-15s: %.3f" % t for t in [
('height average', np.average(self.center)),
('height median', np.median(self.center)),
('height max', np.max(self.center)),
('height min', np.min(self.center)),
('height std', np.std(self.center)),
('slope average', np.average(slopes)),
('slope median', np.median(slopes)),
('slope max', np.max(slopes)),
('slope min', np.min(slopes)),
('slope std', np.std(slopes))
]])
class TestGrid(unittest.TestCase):
def test_diffuse(self):
g = Grid(5)
g.peak(1)
self.assertEqual(g.center[2, 2], 1.0)
g.diffuse(0.1, numexpr=False)
for n in [(2, 1), (2, 3), (1, 2), (3, 2)]:
self.assertAlmostEqual(g.center[n], 0.1)
self.assertAlmostEqual(g.center[2, 2], 0.6)
def test_diffuse_numexpr(self):
g = Grid(5)
g.peak(1)
g.diffuse(0.1, numexpr=False)
h = Grid(5)
h.peak(1)
h.diffuse(0.1, numexpr=True)
self.assertEqual(list(g.center.flat), list(h.center.flat))
def test_avalanche_numexpr(self):
g = Grid(5)
g.peak(1)
g.avalanche(0.1, numexpr=False)
h = Grid(5)
h.peak(1)
h.avalanche(0.1, numexpr=True)
print(g)
print(h)
np.testing.assert_almost_equal(g.center, h.center)
if __name__ == "__main__":
import argparse
parser = argparse.ArgumentParser(description='Erode a terrain while assuming zero boundary conditions.')
parser.add_argument('-I', dest='iterations', type=int, default=1, help='the number of iterations')
parser.add_argument('-Kd', dest='Kd', type=float, default=0.01, help='Diffusion constant')
parser.add_argument('-Kh', dest='Kh', type=float, default=6, help='Maximum stable cliff height')
parser.add_argument('-Kp', dest='Kp', type=float, default=0.1, help='Avalanche probability for unstable cliffs')
parser.add_argument('-Kr', dest='Kr', type=float, default=0.1, help='Average amount of rain per iteration')
parser.add_argument('-Kspring', dest='Kspring', type=float, default=0.0,
help='Average amount of wellwater per iteration')
parser.add_argument('-Kspringx', dest='Kspringx', type=float, default=0.5, help='relative x position of spring')
parser.add_argument('-Kspringy', dest='Kspringy', type=float, default=0.5, help='relative y position of spring')
parser.add_argument('-Kspringr', dest='Kspringr', type=float, default=0.02, help='radius of spring')
parser.add_argument('-Kdep', dest='Kdep', type=float, default=0.1, help='Sediment deposition constant')
parser.add_argument('-Ks', dest='Ks', type=float, default=0.1, help='Soil softness constant')
parser.add_argument('-Kc', dest='Kc', type=float, default=1.0, help='Sediment capacity')
parser.add_argument('-Ka', dest='Ka', type=float, default=2.0, help='Slope dependency of erosion')
parser.add_argument(
'-ri',
action='store_true',
dest='rawin',
default=False,
help='use Blender raw format for input')
parser.add_argument(
'-ro',
action='store_true',
dest='rawout',
default=False,
help='use Blender raw format for output')
parser.add_argument('-i', action='store_true', dest='useinputfile', default=False,
help='use an inputfile (instead of just a synthesized grid)')
parser.add_argument(
'-t',
action='store_true',
dest='timingonly',
default=False,
help='do not write anything to an output file')
parser.add_argument('-infile', type=str, default="-", help='input filename')
parser.add_argument('-outfile', type=str, default="-", help='output filename')
parser.add_argument('-Gn', dest='gridsize', type=int, default=20, help='Gridsize (always square)')
parser.add_argument('-Gp', dest='gridpeak', type=float, default=0, help='Add peak with given height')
parser.add_argument('-Gs', dest='gridshelf', type=float, default=0, help='Add shelve with given height')
parser.add_argument('-Gm', dest='gridmesa', type=float, default=0, help='Add mesa with given height')
parser.add_argument('-Gr', dest='gridrandom', type=float, default=0,
help='Add random values between 0 and given value')
parser.add_argument('-m', dest='threads', type=int, default=1, help='number of threads to use')
parser.add_argument('-u', action='store_true', dest='unittest', default=False, help='perform unittests')
parser.add_argument('-a', action='store_true', dest='analyze', default=False,
help='show some statistics of input and output meshes')
parser.add_argument('-d', action='store_true', dest='dump', default=False,
help='show sediment and water meshes at end of run')
parser.add_argument('-n', action='store_true', dest='usenumexpr', default=False, help='use numexpr optimizations')
args = parser.parse_args()
print("\nInput arguments:")
print("\n".join("%-15s: %s" % t for t in sorted(vars(args).items())), file=sys.stderr)
if args.unittest:
unittest.main(argv=[sys.argv[0]])
sys.exit(0)
if args.useinputfile:
if args.rawin:
grid = Grid.fromRaw(args.infile)
else:
grid = Grid.fromFile(args.infile)
else:
grid = Grid(args.gridsize)
if args.gridpeak > 0:
grid.peak(args.gridpeak)
if args.gridmesa > 0:
grid.mesa(args.gridmesa)
if args.gridshelf > 0:
grid.shelf(args.gridshelf)
if args.gridrandom > 0:
grid.random(args.gridrandom)
if args.analyze:
print('\nstatistics of the input grid:\n\n', grid.analyze(), file=sys.stderr, sep='')
t = getptime()
for g in range(args.iterations):
if args.Kd > 0:
grid.diffuse(args.Kd, args.usenumexpr)
if args.Kh > 0 and args.Kp > rand():
grid.avalanche(args.Kh, args.usenumexpr)
if args.Kr > 0 or args.Kspring > 0:
grid.fluvial_erosion(
args.Kr,
args.Kc,
args.Ks,
args.Kdep,
args.Ka,
args.Kspring,
args.Kspringx,
args.Kspringy,
args.Kspringr,
args.usenumexpr,
)
t = getptime() - t
print("\nElapsed time: %.1f seconds, max memory %.1f Mb.\n" % (t, grid.maxrss), file=sys.stderr)
if args.analyze:
print('\nstatistics of the output grid:\n\n', grid.analyze(), file=sys.stderr, sep='')
if not args.timingonly:
if args.rawout:
grid.toRaw(args.outfile, vars(args))
else:
grid.toFile(args.outfile)
if args.dump:
print("sediment\n", np.array_str(grid.sediment, precision=3), file=sys.stderr)
print("water\n", np.array_str(grid.water, precision=3), file=sys.stderr)
print("sediment concentration\n", np.array_str(grid.sediment / grid.water, precision=3), file=sys.stderr)