Seed point volume

Seed point volume#

A seed point volume is a volume zone defined by one or more interior seed points rather than by enclosing surfaces. The mesher runs a flood fill from the seed point(s) to identify the region they sit in and meshes it as a separate zone. This is convenient for cavities bounded by many baffles, where listing every enclosing surface would be impractical.

Available Options#

Option

Description

Applicable

Name

Identifier for the seed point volume

always

Seed point

Interior point(s) that flood-fill to define the zone

always

Axes

Two orthogonal vectors defining principal directions

always

Detailed Descriptions#

Name#

Identifier for the seed point volume entity.

  • Required

Note: The volume zone name in the solver matches the seed point volume name.

Seed point#

The interior point(s) used to identify the volume zone. Add a point with the + button; each point is entered as X, Y, Z coordinates with a length unit. Use the eye icon to toggle its visibility in the 3D scene and the trash icon to remove it.

  • Required

  • Units: Length

Notes:

  • Place each seed point inside the region you want meshed as its own zone

  • The number of seed points allowed per volume depends on the surface mesher:

    • With the Geometry AI surface mesher, a single seed point volume may carry several seed points, which the flood fill merges into one zone (useful when baffles split a region into several compartments)

    • With snappy, each seed point volume must carry exactly one seed point

  • With snappy, avoid placing a seed point on round (integer) coordinates, which can cause the snappyHexMesh utility to fail

Axes#

Two orthogonal vectors defining the principal directions for the volume.

  • Optional

  • Default: Not specified

Notes:

  • Required when using the volume with porous media models that have directional (anisotropic) properties

  • The two axes must be orthogonal (perpendicular) to each other

  • The third axis is automatically computed to complete the right-handed coordinate system

Important

Seed point volumes require the Geometry AI surface mesher or snappy; they are not supported with the beta surface mesher or the legacy mesher. With the Geometry AI workflow, a setup using seed point volumes is restricted to a single custom zones container that holds only seed point volumes (it cannot be combined with enclosing-surface custom volumes, nor with a second custom zones container). The snappy workflow has no such restriction.

See also

  • For the underlying meshing behaviour (flood fill, per-mesher seed-count rules, and the Geometry AI single-zone limitation), see the Volume Mesher user guide.

  • Seed point volumes are turned into mesh zones through a Custom zones configuration.

🐍 Python Example Usage

See also

SeedpointVolume

import flow360 as fl

# A single internal fluid zone identified by one seed point
fluid = fl.SeedpointVolume(
    name="fluid",
    point_in_mesh=[(0.234, 0.18172, 2.1324) * fl.u.m],
)

# A zone carrying several seed points (Geometry AI flood-fills them into one zone)
radiator = fl.SeedpointVolume(
    name="radiator",
    point_in_mesh=[
        (2040.53452, -405.234, 395.34243) * fl.u.mm,
        (2040.53452, 405.234, 395.34243) * fl.u.mm,
    ],
)
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