Particle Trace (Streamline/Pathline) usage

Utilize EnSight Particle Trace (aka Streamline/Pathline) to visualize a vector through the domain. Create Streamline, animate, allow for dynamic change.

Start an EnSight session

Launch and connect to an instance of EnSight. This example uses a local EnSight installation.

from ansys.pyensight.core import LocalLauncher

session = LocalLauncher().start()
# Setup shortcuts for long winded calls.
eocore = session.ensight.objs.core
eonums = session.ensight.objs.enums
eoutil = session.ensight.utils

Load a dataset

Load Shuttle data included in the EnSight installation and render

xyz_file = f"{session.cei_home}/ensight{session.cei_suffix}/data/plot3d/shuttle.xyz"
q_file = f"{session.cei_home}/ensight{session.cei_suffix}/data/plot3d/shuttle.q"
session.load_data(
    data_file=xyz_file,
    result_file=q_file,
    file_format="PLOT3D",
    representation="3D_feature_2D_full",
)
session.show("image", width=800, height=600)

The PLOT3D reader only reads the volume by default. Now, extract a

particular IJK range for the surface of the shuttle

---

session.ensight.data_partbuild.begin()
session.ensight.case.select("Case 1")
session.ensight.data_partbuild.data_type("structured")
session.ensight.data_partbuild.group("OFF")
session.ensight.data_partbuild.select_begin(1)
session.ensight.data_partbuild.domain("all")
session.ensight.data_partbuild.noderange_i(1, 53)
session.ensight.data_partbuild.noderange_j(1, 63)
session.ensight.data_partbuild.noderange_k(1, 1)
session.ensight.data_partbuild.nodestep(1, 1, 1)
session.ensight.data_partbuild.nodedelta(0, 0, 0)
session.ensight.data_partbuild.description("Shuttle")
session.ensight.data_partbuild.create()
session.ensight.part.select_byname_begin("(CASE:Case 1)Shuttle")
session.ensight.case.select("Case 1")
session.ensight.data_partbuild.end()

Setup the View

Set View, Turn on Symmetry, turn off visibility of flow domain.

session.ensight.view_transf.rotate(-109.084335, -1.64276719, 0)
session.ensight.view_transf.rotate(-2.38553524, 115.462845, 0)
session.ensight.view_transf.zoom(0.489253074)
session.ensight.view_transf.look_at(2.4110589, 0.567389309, 0.241451085)
session.ensight.view_transf.look_from(2.4110589, 0.567389309, 5.69335651)

session.ensight.part.select_all()
session.ensight.part.modify_begin()
session.ensight.part.symmetry_type("mirror")
session.ensight.part.symmetry_mirror_y("ON")
session.ensight.part.modify_end()

session.ensight.part.select_begin(1)
session.ensight.part.modify_begin()
session.ensight.part.visible("OFF")
session.ensight.part.modify_end()

Create a Particle Trace using the Line Tool Specification

Using the 3D parts as the parent, with the line tool as the emission type “Momentum” as the vector, and 50 points alone the line as emitter locations.

pt1 = [0.1245, 0.064366, -0.03438]
pt2 = [1.0018, 0.399756, -0.03258]
parent_parts = eoutil.parts.select_parts_by_dimension(3)
npts = 50  # number of emitters
vector_var = eocore.VARIABLES["Momentum"][0]  # Vector variable to use
strpart = eoutil.parts.create_particle_trace_from_line(
    "Streamline",
    vector_var,
    point1=pt1,
    point2=pt2,
    num_points=npts,
    source_parts=parent_parts,
    direction="+/-",
)
session.show("image", width=800, height=600)

Change Visual Attributes

Modify the attributes of the Streamline for visual clarity

strpart.REPRESENTATION = eonums.TRACE_TUBE
strpart.WIDTHSCALEFACTOR = 0.012
strpart.COLORBYPALETTE = "Momentum"
session.show("image", width=800, height=600)

Animate the Streamlines

Turn OFF the streamlines (to see the animate under) Turn ON the animate streamlines. Change to Sphere representation, size, and adjust speed and length.

strpart.VISIBLE = False
strpart.ANIMATE = True
eocore.HEADTYPE = eonums.ATRACE_HEAD_SPHERE
eocore.HEADSCALE = 0.03
eocore.PARTICLETIME = 2.0
eocore.DELTATIME = 0.065
eocore.MULTIPLEPULSES = True
session.show("image", width=800, height=600)

Close the session

# sphinx_gallery_thumbnail_path = '_static/03_ptrace_2.png'
session.close()