18. Targeted: Trame

18.1. Introduction

Trame, is Python framework to build applications with interactive scientific visualization that can be driven from a Web browser. Those applications can leverage a VTK and/or ParaView backend for large data processing and rendering along with many other Python libraries.

The trame website provide many examples showcasing VTK or ParaView. - https://kitware.github.io/trame/

18.2. Running a trame application

ParaView 5.13+ now support a --venv /path/to/venv that let you extend ParaView python with your own virtual-environment and therefore libraries. While this option is very powerful, they are a couple caveats that needs your attention.

1. The venv needs to be created with the same version as ParaView is using. For example, ParaView 5.13 is using ParaView 3.10, which means the venv needs to be created with a Python 3.10.*.

2. The venv can not provide different version of the Python libraries that are already available within ParaView (i.e. numpy, pandas).

18.2.1. Virtual Environment creation

python3.10 -m venv .venv
source .venv/bin/activate
pip install -U pip
pip install trame trame-vtk trame-vuetify # Add anything more you plan to use

18.2.2. Running a script locally

If you create a pv_cone.py file with the following content.

r"""
Installation requirements:
    pip install trame trame-vuetify trame-vtk
"""

from trame.app import get_server
from trame.decorators import TrameApp, change
from trame.widgets import vuetify3 as v3, paraview as pv_widgets
from trame.ui.vuetify3 import SinglePageLayout

from paraview import simple

# -----------------------------------------------------------------------------

@TrameApp()
class ConeApp:
    def __init__(self, server=None):
        self.server = get_server(server, client_type="vue3")

        self.cone = simple.Cone()
        self.representation = simple.Show(self.cone)
        self.view = simple.Render()

        self.state.trame__title = "ParaView - Cone"
        self.ui = self._build_ui()

    @property
    def state(self):
        return self.server.state

    @property
    def ctrl(self):
        return self.server.controller

    @change("resolution")
    def on_resolution_change(self, resolution, **_):
        self.cone.Resolution = resolution
        self.ctrl.view_update()

    def reset_resolution(self):
        self.state.resolution = 6

    def _build_ui(self):
        with SinglePageLayout(self.server, full_height=True) as layout:
            layout.icon.click = self.ctrl.view_reset_camera
            layout.title.set_text("ParaView - Cone")

            with layout.toolbar:
                v3.VSpacer()
                v3.VSlider(
                    v_model=("resolution", 6),
                    min=3,
                    max=60,
                    step=1,
                    hide_details=True,
                    dense=True,
                    style="max-width: 300px",
                )
                v3.VDivider(vertical=True, classes="mx-2")
                with v3.VBtn(icon=True, click=self.reset_resolution):
                    v3.VIcon("mdi-undo-variant")

            with layout.content:
                with v3.VContainer(fluid=True, classes="pa-0 fill-height"):
                    html_view = pv_widgets.VtkRemoteView(self.view, interactive_ratio=1)
                    self.ctrl.view_reset_camera = html_view.reset_camera
                    self.ctrl.view_update = html_view.update

            return layout

# -----------------------------------------------------------------------------

def main(**kwargs):
    app = ConeApp()
    app.server.start(**kwargs)

# -----------------------------------------------------------------------------

if __name__ == "__main__":
    main()

You can run it by doing the following

pvpython --venv .venv ./pv_cone.py

18.2.3. Running a packaged application

Assuming that application is available in your virtual environment, you can run the following

# vtk.js example
pvpython --venv .venv -m trame.app.demo

# ParaView example
pvpython --venv .venv -m trame.app.pv_demo