Creating Models from Primitives¶

cavsim3d provides built-in parametric primitives for common waveguide and cavity shapes. These are useful for quick prototyping, benchmarking, and validation against analytical solutions.

Available Primitives¶

Primitive	Class	Key Parameters
Rectangular Waveguide	RectangularWaveguide	a (width), L (length), b (height)
Circular Waveguide	CircularWaveguide	radius, length
Box Cavity	Box	dimensions, port_faces

1. Rectangular Waveguide¶

A rectangular waveguide with width $a$, height $b$ (defaults to $a/2$), and length $L$. Ports are automatically assigned at each end.

In [ ]:

from cavsim3d.geometry.primitives import RectangularWaveguide

# Create a rectangular waveguide: 100mm wide, 200mm long
rwg = RectangularWaveguide(a=0.1, L=0.2)
rwg.print_info()
rwg.show('geometry')

from cavsim3d.geometry.primitives import RectangularWaveguide # Create a rectangular waveguide: 100mm wide, 200mm long rwg = RectangularWaveguide(a=0.1, L=0.2) rwg.print_info() rwg.show('geometry')

In [ ]:

# Generate mesh and visualise
rwg.generate_mesh(maxh=0.02)
rwg.show('mesh')

# Generate mesh and visualise rwg.generate_mesh(maxh=0.02) rwg.show('mesh')

2. Circular Waveguide¶

A circular waveguide defined by its radius and length.

In [ ]:

from cavsim3d.geometry.primitives import CircularWaveguide

# Create a circular waveguide: 50mm radius, 200mm long
cwg = CircularWaveguide(radius=0.05, length=0.2)
cwg.print_info()
cwg.show('geometry')

from cavsim3d.geometry.primitives import CircularWaveguide # Create a circular waveguide: 50mm radius, 200mm long cwg = CircularWaveguide(radius=0.05, length=0.2) cwg.print_info() cwg.show('geometry')

In [ ]:

cwg.generate_mesh(maxh=0.02)
cwg.show('mesh')

cwg.generate_mesh(maxh=0.02) cwg.show('mesh')

3. Box Cavity¶

A general box-shaped cavity where you can specify which faces serve as ports.

In [ ]:

from cavsim3d.geometry.primitives import Box

# Create a box cavity: 100mm x 50mm x 200mm with ports on z-faces
box = Box(dimensions=(0.1, 0.05, 0.2), port_faces=('Min(Z)', 'Max(Z)'))
box.print_info()
box.show('geometry')

from cavsim3d.geometry.primitives import Box # Create a box cavity: 100mm x 50mm x 200mm with ports on z-faces box = Box(dimensions=(0.1, 0.05, 0.2), port_faces=('Min(Z)', 'Max(Z)')) box.print_info() box.show('geometry')

In [ ]:

box.generate_mesh(maxh=0.02)
box.show('mesh')

box.generate_mesh(maxh=0.02) box.show('mesh')

4. Building an Assembly from Primitives¶

Primitives can be combined into assemblies for multi-component analysis.

In [ ]:

from cavsim3d.core.em_project import EMProject

proj = EMProject(name='primitive_assembly', base_dir='./simulations', new=True)
assembly = proj.create_assembly(main_axis='Z')

# Build an assembly from two rectangular waveguide sections
rwg1 = RectangularWaveguide(a=0.1, L=0.2)
rwg2 = RectangularWaveguide(a=0.1, L=0.2)

assembly.add("section1", rwg1)
assembly.add("section2", rwg2, after="section1")

assembly.build()
assembly.generate_mesh(maxh=0.02)
assembly.show('geometry')

from cavsim3d.core.em_project import EMProject proj = EMProject(name='primitive_assembly', base_dir='./simulations', new=True) assembly = proj.create_assembly(main_axis='Z') # Build an assembly from two rectangular waveguide sections rwg1 = RectangularWaveguide(a=0.1, L=0.2) rwg2 = RectangularWaveguide(a=0.1, L=0.2) assembly.add("section1", rwg1) assembly.add("section2", rwg2, after="section1") assembly.build() assembly.generate_mesh(maxh=0.02) assembly.show('geometry')

Summary¶

In this tutorial we:

1. Created rectangular and circular waveguides from parametric primitives
2. Created a box cavity with custom port faces
3. Visualised geometry and meshes for each primitive
4. Combined primitives into an assembly

Next: See Creating Geometry from the Project Object for a streamlined workflow.