example_nurbs_surface Program

Uses

  • program~~example_nurbs_surface~~UsesGraph program~example_nurbs_surface example_nurbs_surface module~forcad forcad program~example_nurbs_surface->module~forcad module~forcad_nurbs_curve forcad_nurbs_curve module~forcad->module~forcad_nurbs_curve module~forcad_nurbs_surface forcad_nurbs_surface module~forcad->module~forcad_nurbs_surface module~forcad_nurbs_volume forcad_nurbs_volume module~forcad->module~forcad_nurbs_volume module~forcad_utils forcad_utils module~forcad->module~forcad_utils module~forcad_nurbs_curve->module~forcad_utils module~forcad_nurbs_surface->module~forcad_utils module~forcad_nurbs_volume->module~forcad_utils stdlib_quadrature stdlib_quadrature module~forcad_utils->stdlib_quadrature

This program demonstrates the usage of a NURBS surface object to create, and finalize a NURBS surface. It sets up control points and weights, generates the surface, and exports the control points and the surface to VTK files at various stages.

Define control points for the NURBS surface

Define weights for the control points

Set control points and weights for the NURBS surface object

Deallocate local arrays

Export initial control points to a VTK file

Generate the NURBS surface with a resolution of 30x30

Export the generated surface to a VTK file

Show the control geometry and geometry using PyVista

Finalize the NURBS surface object


Calls

program~~example_nurbs_surface~~CallsGraph program~example_nurbs_surface example_nurbs_surface none~set~3 nurbs_surface%set program~example_nurbs_surface->none~set~3 proc~create~3 nurbs_surface%create program~example_nurbs_surface->proc~create~3 proc~export_xc~3 nurbs_surface%export_Xc program~example_nurbs_surface->proc~export_xc~3 proc~export_xg~3 nurbs_surface%export_Xg program~example_nurbs_surface->proc~export_xg~3 proc~finalize~3 nurbs_surface%finalize program~example_nurbs_surface->proc~finalize~3 proc~generate_xc~3 generate_Xc program~example_nurbs_surface->proc~generate_xc~3 proc~show~3 nurbs_surface%show program~example_nurbs_surface->proc~show~3 proc~set1~3 nurbs_surface%set1 none~set~3->proc~set1~3 proc~set2~3 nurbs_surface%set2 none~set~3->proc~set2~3 proc~set3~3 nurbs_surface%set3 none~set~3->proc~set3~3 proc~set4~3 nurbs_surface%set4 none~set~3->proc~set4~3 interface~compute_xg~3 compute_Xg proc~create~3->interface~compute_xg~3 interface~ndgrid ndgrid proc~create~3->interface~ndgrid proc~is_rational~3 nurbs_surface%is_rational proc~create~3->proc~is_rational~3 proc~cmp_elem_xc_vis~3 nurbs_surface%cmp_elem_Xc_vis proc~export_xc~3->proc~cmp_elem_xc_vis~3 proc~cmp_elem_xg_vis~3 nurbs_surface%cmp_elem_Xg_vis proc~export_xg~3->proc~cmp_elem_xg_vis~3 proc~ndgrid2 ndgrid2 interface~ndgrid->proc~ndgrid2 proc~ndgrid3 ndgrid3 interface~ndgrid->proc~ndgrid3 interface~elemconn_c0 elemConn_C0 proc~cmp_elem_xc_vis~3->interface~elemconn_c0 proc~cmp_elem_xg_vis~3->interface~elemconn_c0 proc~cmp_degree~3 nurbs_surface%cmp_degree proc~set1~3->proc~cmp_degree~3 proc~cmp_nc~3 nurbs_surface%cmp_nc proc~set1~3->proc~cmp_nc~3 proc~set2~3->proc~cmp_nc~3 proc~compute_knot_vector compute_knot_vector proc~set2~3->proc~compute_knot_vector proc~set3~3->proc~cmp_degree~3 proc~cmp_elemconn_c0_l cmp_elemConn_C0_L interface~elemconn_c0->proc~cmp_elemconn_c0_l proc~cmp_elemconn_c0_s cmp_elemConn_C0_S interface~elemconn_c0->proc~cmp_elemconn_c0_s proc~cmp_elemconn_c0_v cmp_elemConn_C0_V interface~elemconn_c0->proc~cmp_elemconn_c0_v proc~get_multiplicity~3 nurbs_surface%get_multiplicity proc~cmp_degree~3->proc~get_multiplicity~3 interface~compute_multiplicity compute_multiplicity proc~cmp_nc~3->interface~compute_multiplicity proc~repelem repelem proc~compute_knot_vector->proc~repelem proc~compute_multiplicity1 compute_multiplicity1 interface~compute_multiplicity->proc~compute_multiplicity1 proc~compute_multiplicity2 compute_multiplicity2 interface~compute_multiplicity->proc~compute_multiplicity2 proc~get_multiplicity~3->interface~compute_multiplicity

Variables

Type Attributes Name Initial
real(kind=rk), allocatable :: Wc(:)

Arrays for control points and weights
real(kind=rk), allocatable :: Xc(:,:)

Arrays for control points and weights
type(nurbs_surface) :: nurbs

Declare a NURBS surface object

Functions

function generate_Xc(num_rows, num_cols, peak_height) result(control_points)

Arguments

Type IntentOptional Attributes Name
integer, intent(in) :: num_rows
integer, intent(in) :: num_cols
real(kind=rk), intent(in) :: peak_height

Return Value real(kind=rk), allocatable, (:,:)


Source Code

program example_nurbs_surface

    use forcad, only: rk, nurbs_surface

    implicit none
    type(nurbs_surface) :: nurbs             !! Declare a NURBS surface object
    real(rk), allocatable :: Xc(:,:), Wc(:)  !! Arrays for control points and weights

    !-----------------------------------------------------------------------------
    ! Setting up the NURBS surface
    !-----------------------------------------------------------------------------

    !> Define control points for the NURBS surface
    Xc = generate_Xc(10, 10, 1.5_rk)

    !> Define weights for the control points
    allocate(Wc(size(Xc,1)), source=1.0_rk)

    !> Set control points and weights for the NURBS surface object
    call nurbs%set([10,10],Xc,Wc)

    !> Deallocate local arrays
    deallocate(Xc, Wc)

    !> Export initial control points to a VTK file
    call nurbs%export_Xc('vtk/demo_surface_Xc.vtk')

    !-----------------------------------------------------------------------------
    ! Creating the NURBS surface
    !-----------------------------------------------------------------------------

    !> Generate the NURBS surface with a resolution of 30x30
    call nurbs%create(res1=30, res2=30)

    !> Export the generated surface to a VTK file
    call nurbs%export_Xg('vtk/demo_surface_Xg.vtk')

    !-----------------------------------------------------------------------------
    ! Visualization using PyVista
    ! Note: PyVista is required for visualization. Install it using `pip install pyvista`
    !-----------------------------------------------------------------------------

    !> Show the control geometry and geometry using PyVista
    call nurbs%show('vtk/demo_surface_Xc.vtk','vtk/demo_surface_Xg.vtk')

    !-----------------------------------------------------------------------------
    ! Finalizing
    !-----------------------------------------------------------------------------

    !> Finalize the NURBS surface object
    call nurbs%finalize()

contains

    !-----------------------------------------------------------------------------
    function generate_Xc(num_rows, num_cols, peak_height) result(control_points)
        integer, intent(in) :: num_rows, num_cols
        real(rk), intent(in) :: peak_height
        real(rk), allocatable :: control_points(:,:)
        integer :: i, j
        real(rk) :: x_spacing, y_spacing, x_offset, y_offset
        x_spacing = 1.0_rk / real(num_cols - 1, rk)
        y_spacing = 1.0_rk / real(num_rows - 1, rk)
        x_offset = -0.5_rk
        y_offset = -0.5_rk
        allocate(control_points(num_rows * num_cols, 3))
        do i = 1, num_rows
            do j = 1, num_cols
                control_points((i - 1) * num_cols + j, 1) = x_offset + real(j - 1, rk) * x_spacing
                control_points((i - 1) * num_cols + j, 2) = y_offset + real(i - 1, rk) * y_spacing
                control_points((i - 1) * num_cols + j, 3) = &
                    peak_height * exp(-((control_points((i - 1) * num_cols + j, 1) ** 2) &
                    + (control_points((i - 1) * num_cols + j, 2) ** 2))) + 0.5_rk * peak_height * 0.2_rk
            end do
        end do
    end function
    !-----------------------------------------------------------------------------

end program example_nurbs_surface