Dash VTK⑥(VTK dynamic streamlines)

VTK dynamic streamlines

Dash VTKを使って、バイク走行中の風力イメージを表示してみます。

下記URLからbike.vtpファイルtunnel.vtuファイルをダウンロードし、ソースコードと同じフォルダに格納します。

データセット - https://github.com/plotly/dash-vtk/tree/master/demos/usage-vtk-cfd/data

下記のソースコードでは、PyVista/VTKを使用してデータセットを読み込み、Dash VTKを使用して 3D Web ビューで表示しています。

風力イメージを調整するためのコントローラも設定しています。

[ソースコード]

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import os
import random

import dash
import dash_bootstrap_components as dbc
import dash_html_components as html
import dash_core_components as dcc

from dash.dependencies import Input, Output, State

import dash_vtk
from dash_vtk.utils import to_mesh_state, preset_as_options

import vtk

random.seed(42)

# -----------------------------------------------------------------------------
# VTK Pipeline
# -----------------------------------------------------------------------------
class Viz:
def __init__(self, data_directory):
self.color_range = [0, 1]
bike_filename = "bike.vtp"
tunnel_filename = "tunnel.vtu"

# Seeds settings
self.resolution = 10
self.point1 = [-0.4, 0, 0.05]
self.point2 = [-0.4, 0, 1.5]

# VTK Pipeline setup
bikeReader = vtk.vtkXMLPolyDataReader()
bikeReader.SetFileName(bike_filename)
bikeReader.Update()
self.bike_mesh = to_mesh_state(bikeReader.GetOutput())

tunnelReader = vtk.vtkXMLUnstructuredGridReader()
tunnelReader.SetFileName(tunnel_filename)
tunnelReader.Update()

self.lineSeed = vtk.vtkLineSource()
self.lineSeed.SetPoint1(*self.point1)
self.lineSeed.SetPoint2(*self.point2)
self.lineSeed.SetResolution(self.resolution)

streamTracer = vtk.vtkStreamTracer()
streamTracer.SetInputConnection(tunnelReader.GetOutputPort())
streamTracer.SetSourceConnection(self.lineSeed.GetOutputPort())
streamTracer.SetIntegrationDirectionToForward()
streamTracer.SetIntegratorTypeToRungeKutta45()
streamTracer.SetMaximumPropagation(3)
streamTracer.SetIntegrationStepUnit(2)
streamTracer.SetInitialIntegrationStep(0.2)
streamTracer.SetMinimumIntegrationStep(0.01)
streamTracer.SetMaximumIntegrationStep(0.5)
streamTracer.SetMaximumError(0.000001)
streamTracer.SetMaximumNumberOfSteps(2000)
streamTracer.SetTerminalSpeed(0.00000000001)

self.tubeFilter = vtk.vtkTubeFilter()
self.tubeFilter.SetInputConnection(streamTracer.GetOutputPort())
self.tubeFilter.SetRadius(0.01)
self.tubeFilter.SetNumberOfSides(6)
self.tubeFilter.CappingOn()
self.tubeFilter.Update()

def updateSeedPoints(self, p1_y, p2_y, resolution):
self.point1[1] = p1_y
self.point2[1] = p2_y
self.resolution = resolution

self.lineSeed.SetPoint1(*self.point1)
self.lineSeed.SetPoint2(*self.point2)
self.lineSeed.SetResolution(resolution)

def getTubesMesh(self, color_by_field_name):
self.tubeFilter.Update()
ds = self.tubeFilter.GetOutput()
mesh_state = to_mesh_state(ds, color_by_field_name)
self.color_range = mesh_state["field"]["dataRange"]
return mesh_state

def getBikeMesh(self):
return self.bike_mesh

def getColorRange(self):
return self.color_range

def getSeedState(self):
return {
"point1": self.point1,
"point2": self.point2,
"resolution": self.resolution,
}

# -----------------------------------------------------------------------------
# GUI setup
# -----------------------------------------------------------------------------
app = dash.Dash(__name__, external_stylesheets=[dbc.themes.BOOTSTRAP])
server = app.server
viz = Viz(os.path.join(os.path.dirname(__file__), "data"))

# -----------------------------------------------------------------------------
# 3D Viz
# -----------------------------------------------------------------------------
vtk_view = dash_vtk.View(
id="vtk-view",
children=[
dash_vtk.GeometryRepresentation(
id="bike-rep",
children=[
dash_vtk.Mesh(
id="bike",
state=viz.getBikeMesh(),
)
],
),
dash_vtk.GeometryRepresentation(
id="tubes-rep",
colorMapPreset="erdc_rainbow_bright",
colorDataRange=viz.getColorRange(),
children=[
dash_vtk.Mesh(
id="tubes-mesh",
state=viz.getTubesMesh("p"),
)
],
),
dash_vtk.GeometryRepresentation(
id="seed-rep",
property={
"color": [0.8, 0, 0],
"representation": 0,
"pointSize": 8,
},
children=[
dash_vtk.Algorithm(
id="seed-line",
vtkClass="vtkLineSource",
state=viz.getSeedState(),
)
],
),
],
)

# -----------------------------------------------------------------------------
# Control UI
# -----------------------------------------------------------------------------
high = 0.6
low = -0.55

controls = [
dbc.Card(
[
dbc.CardHeader("Seeds"),
dbc.CardBody(
[
html.P("Line seed position (from bottom):"),
dcc.Slider(
id="point-1",
min=low,
max=high,
step=0.05,
value=0,
marks={low: str(low), high: str(high)},
),
html.Br(),
html.P("Line seed position (from top):"),
dcc.Slider(
id="point-2",
min=low,
max=high,
step=0.05,
value=0,
marks={low: str(low), high: str(high)},
),
html.Br(),
html.P("Line resolution:"),
dcc.Slider(
id="seed-resolution",
min=5,
max=50,
step=1,
value=10,
marks={5: "5", 50: "50"},
),
]
),
]
),
html.Br(),
dbc.Card(
[
dbc.CardHeader("Color By"),
dbc.CardBody(
[
html.P("Field name"),
dcc.Dropdown(
id="color-by",
options=[
{"label": "p", "value": "p"},
{"label": "Rotation", "value": "Rotation"},
{"label": "U", "value": "U"},
{"label": "Vorticity", "value": "Vorticity"},
{"label": "k", "value": "k"},
],
value="p",
),
html.Br(),
html.P("Color Preset"),
dcc.Dropdown(
id="preset",
options=preset_as_options,
value="erdc_rainbow_bright",
),
]
),
]
),
]

# -----------------------------------------------------------------------------
# App UI
# -----------------------------------------------------------------------------
app.layout = dbc.Container(
fluid=True,
style={"marginTop": "15px", "height": "calc(100vh - 30px)"},
children=[
dbc.Row(
[
dbc.Col(width=4, children=controls),
dbc.Col(
width=8,
children=[
html.Div(vtk_view, style={"height": "100%", "width": "100%"})
],
),
],
style={"height": "100%"},
),
],
)

# -----------------------------------------------------------------------------
# Handle controls
# -----------------------------------------------------------------------------
@app.callback(
[
Output("seed-line", "state"),
Output("tubes-mesh", "state"),
Output("tubes-rep", "colorDataRange"),
Output("tubes-rep", "colorMapPreset"),
Output("vtk-view", "triggerRender"),
],
[
Input("point-1", "drag_value"),
Input("point-2", "drag_value"),
Input("point-1", "value"),
Input("point-2", "value"),
Input("seed-resolution", "value"),
Input("color-by", "value"),
Input("preset", "value"),
],
)
def update_seeds(y1_drag, y2_drag, y1, y2, resolution, colorByField, presetName):
triggered = dash.callback_context.triggered

if triggered and "drag_value" in triggered[0]["prop_id"]:
viz.updateSeedPoints(y1_drag, y2_drag, resolution)
return [
viz.getSeedState(),
dash.no_update,
dash.no_update,
dash.no_update,
random.random(), # trigger a render
]

viz.updateSeedPoints(y1, y2, resolution)
return [
viz.getSeedState(),
viz.getTubesMesh(colorByField),
viz.getColorRange(),
presetName,
random.random(), # trigger a render
]
# -----------------------------------------------------------------------------
if __name__ == "__main__":
app.run_server(debug=True)

[ブラウザで表示]

バイク走行中の風力イメージを表示できました。

各コントローラを使って風力イメージの表示を調整したり、ドラッグすることにより角度を変えて表示することが可能です。