OffScreenRendering

Description¶

This example renders a scene directly to a file without displaying a window. You must turn on VTK_OPENGL_HAS_OSMESA in the VTK advanced build configuration.

Other languages

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Question

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Code¶

OffScreenRendering.py

#!/usr/bin/env python3

# noinspection PyUnresolvedReferences
import vtkmodules.vtkRenderingOpenGL2
from vtkmodules.vtkCommonColor import vtkNamedColors
from vtkmodules.vtkFiltersSources import vtkSphereSource
from vtkmodules.vtkIOImage import vtkPNGWriter
from vtkmodules.vtkRenderingCore import (
    vtkActor,
    vtkGraphicsFactory,
    vtkPolyDataMapper,
    vtkRenderer,
    vtkRenderWindow,
    vtkWindowToImageFilter
)


def main():
    colors = vtkNamedColors()

    # Setup off-screen rendering.
    graphics_factory = vtkGraphicsFactory(off_screen_only_mode=True, use_mesa_classes=True)

    # Create a sphere
    sphere_source = vtkSphereSource()

    # Create a mapper and actor.
    mapper = vtkPolyDataMapper()
    sphere_source >> mapper

    actor = vtkActor(mapper=mapper)
    actor.property.color = colors.GetColor3d('White')

    # A renderer and render window.
    renderer = vtkRenderer(background=colors.GetColor3d('SlateGray'))
    render_window = vtkRenderWindow(off_screen_rendering=True)
    render_window.AddRenderer(renderer)

    # Add the actor to the scene.
    renderer.AddActor(actor)

    render_window.Render()

    window_to_image_filter = vtkWindowToImageFilter(input=render_window)
    window_to_image_filter.update()

    writer = vtkPNGWriter()
    writer.SetFileName('screenshot.png')
    window_to_image_filter >> writer
    writer.Write()


if __name__ == '__main__':
    main()