Surface Mesh

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From version 4.0.0, surface mesh export has been extended and renamed for clarity.
The old option addMaterialIds has been replaced with addInterfaces.
Additional options control how multiple materials and level sets are combined.

Overview

Use the domain member function saveSurfaceMesh or getSurfaceMesh to export the triangulated surface of a geometry.
The function can output either:

• the topmost surface (default), or
• all material interfaces when addInterfaces is enabled.

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API

Get the surface mesh

SmartPointer<viennals::Mesh<NumericType>>
getSurfaceMesh(bool addInterfaces = false,
               double wrappingLayerEpsilon = 0.01,
               bool boolMaterials = false) const;

• addInterfaces — include all internal material interfaces (not only top surface).
• wrappingLayerEpsilon — small offset used to generate interface wrapping layers (default: 0.01).
• boolMaterials — perform Boolean subtraction between successive level sets.

Save the surface mesh

void saveSurfaceMesh(std::string fileName,
                     bool addInterfaces = true,
                     double wrappingLayerEpsilon = 0.01,
                     bool boolMaterials = false) const;

Writes the resulting triangulated mesh to a .vtp file including optional material and metadata information.

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Example usage

C++

auto domain = ps::SmartPointer<ps::Domain<double, 3>>::New();
// ... create geometry in domain ...

// Save top-level surface only
domain->saveSurfaceMesh("surface.vtp", false);

// Save all material interfaces
domain->saveSurfaceMesh("interfaces.vtp", true);

// Save with additional Boolean-based material separation
domain->saveSurfaceMesh("interfaces_bool.vtp", true, 0.01, true);

Python

import viennaps as vps

domain = vps.Domain()
# ... create geometry in domain ...

# Save top surface only
domain.saveSurfaceMesh(fileName="surface.vtp", addInterfaces=False)

# Save all material interfaces
domain.saveSurfaceMesh(fileName="interfaces.vtp", addInterfaces=True)

# Save with Boolean material separation
domain.saveSurfaceMesh(fileName="interfaces_bool.vtp",
                       addInterfaces=True,
                       wrappingLayerEpsilon=0.01,
                       boolMaterials=True)

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Returned mesh

When using getSurfaceMesh(), the returned object is a viennals::Mesh that can be further processed or visualized:

auto mesh = domain->getSurfaceMesh(true);
viennals::VTKWriter<double> writer(mesh, "mesh.vtp");
writer.apply();

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Behavior summary

Option	Description	Default
addInterfaces	Export all material interfaces instead of only the top surface	true
wrappingLayerEpsilon	Distance offset for interface wrapping	0.01
boolMaterials	Apply Boolean subtraction to separate overlapping level sets	false

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Notes

• All exported meshes are in VTK (.vtp) format.
• The mesh includes material IDs and metadata when a MaterialMap is present in the domain.
• Use getSurfaceMesh() for programmatic access or saveSurfaceMesh() for direct file output.