Geometry Creation

Before running any process, you must define the simulation domain and the initial geometry.

The Domain

The ps.Domain class holds the level set data representing your geometry. It requires a grid resolution (gridDelta) and physical extents.

import viennaps as ps
ps.setDimension(2)

# 2D domain: grid spacing 0.5, width 50
domain = ps.Domain(gridDelta=0.5, xExtent=50.0)

For 3D simulations:

ps.setDimension(3)

# 3D domain: grid spacing 0.5, xExtent 50, yExtent 50
domain_3d = ps.Domain(gridDelta=0.5, xExtent=50.0, yExtent=50.0)

Boundary Conditions

You can also specify boundary conditions (periodic, reflective, or infinite):

# Periodic boundaries in x, infinite in vertical direction
domain = ps.Domain(
    gridDelta=0.5,
    xExtent=50.0,
    boundary=ps.BoundaryType.PERIODIC_BOUNDARY
)

Geometric Primitives

ViennaPS provides helper classes to create common initial shapes. These modify the ps.Domain in place.

MakePlane

Creates a flat surface at a specific height, filling everything below with the given material.

# Create a Silicon substrate filling everything below y=0
ps.MakePlane(domain, height=0.0, material=ps.Material.Si).apply()

MakeTrench

Creates a trench structure in a substrate.

ps.MakeTrench(
    domain=domain,
    trenchWidth=20.0,
    trenchDepth=15.0,
    maskHeight=5.0,       # Height of the mask layer above the surface
    trenchTaperAngle=0.0  # Vertical sidewalls (degrees)
).apply()

MakeHole

For 3D simulations, creates a cylindrical or tapered hole.

ps.setDimension(3)
domain_3d = ps.Domain(gridDelta=0.5, xExtent=50.0, yExtent=50.0)

ps.MakeHole(
    domain=domain_3d,
    holeRadius=10.0,
    holeDepth=0.0,        # 0 = mask only (no pre-etched hole)
    maskHeight=5.0
).apply()

Saving Results

You can save the geometry at any point to visualize it.

• saveSurfaceMesh("filename"): Saves the surface mesh as .vtp (efficient for visualization).
• saveVolumeMesh("filename"): Saves the full volume mesh as .vtu (includes material info in bulk).

domain.saveSurfaceMesh("my_geometry")  # Creates my_geometry.vtp
domain.saveVolumeMesh("my_geometry")   # Creates my_geometry_volume.vtu

The file extension is added automatically. Material IDs are stored under the "MaterialIds" label in exported meshes.