Parametrization#

The Parametrization tab provides tools for fitting and working with models.

Sphere
#sphere
Ellipse
#ellipsoid
Cylinder
#cylinder
RBF
#rbf
Mesh
#mesh
Curve
#curve
Sample
#sample
Repair
#repair
Remesh
#remesh
Smooth
#smooth
Project
#project

Parametric Fitting#

Fit basic geometric shapes to point clouds:

Sphere#

Fits a sphere using least squares optimization:

  1. Select a cluster with spherical shape

  2. Click Sphere to fit the model

  3. The fitted sphere appears in the Models section

Ellipsoid#

Fits an ellipsoid using eigenvalue decomposition and least squares optimization:

  1. Select a cluster with ellipsoidal shape

  2. Click Ellipsoid to fit the model

  3. The fitted ellipsoid appears in the Models section

Cylinder#

Fits a cylinder using PCA and iterative refinement:

  1. Select a cluster with cylindrical or tubular shape

  2. Click Cylinder to fit the model

  3. The fitted cylinder appears in the Models section

Non-Parametric Fitting#

RBF (Radial Basis Function)#

Creates smooth, non-parametric surface models through radial basis function interpolation. Ideal for complex, non-parametric shapes that can be represented as height fields, i.e. an open membrane section.

  1. Select a cluster with surface-like structure

  2. Click RBF

  3. Configure interpolation direction:

    • xy: Surface as function of x,y coordinates

    • xz: Surface as function of x,z coordinates

    • yz: Surface as function of y,z coordinates

  4. Click OK to create the interpolated surface

Mesh#

  1. Select a cluster with sufficient point density

  2. Click Mesh

  3. Choose reconstruction method:

    • Alpha Shape: Surface reconstruction using alpha shapes

    • Ball Pivoting: Robust surface reconstruction for structured data

    • Poisson: Watertight surface reconstruction

    • Flying Edges: Fast isosurface extraction for dense segmentations

  4. Configure method-specific parameters:

    Alpha Shape Parameters:

    • Alpha: Controls shape complexity (higher = coarser features)

    • Edge Length: Target edge length for remeshing (-1 = auto)

    Ball Pivoting Parameters:

    • Radii: Ball radii for reconstruction (comma-separated, e.g., “5,3.5,1.0”)

    • Hole Size: Maximum hole area to fill (-1 = fill all)

    • Edge Length: Target edge length for remeshing (-1 = auto)

    Poisson Parameters:

    • Depth: Octree depth (higher = more detail)

    • Neighbors: Number of neighbors for normal estimation

    • Distance: Drop vertices further than this from input

    • Density Quantile: Remove low-confidence vertices

  5. Set fairing parameters (Alpha Shape and Ball Pivoting):

    • Smoothness: Balance between position anchoring and curvature minimization (0 = stay in place, 1 = full smoothing)

    • Curvature Weight: Higher-order smoothing for curvature continuity

    • Pressure: Normal displacement of inferred vertices (positive = expand, negative = contract)

  6. Click OK to generate the mesh

Note: Mesh quality depends on point cloud density and noise levels. For sparse data, try larger ball pivoting radii or lower Poisson depth.

Curve#

Fits spline curves of requested order to sequential control point data. Good for creating smooth curves from hand-drawn paths:

  1. Create control points using drawing mode:

    • Press Shift+A to enter curve drawing mode

    • Click to place control points in sequence

    • Press Enter to complete the curve

    • OR select an existing cluster with linear structure

  2. Click Curve

  3. Configure spline parameters: - Order: Spline degree (1=linear, 3=cubic, 5=quintic)

  4. Click OK to fit the curve

Sampling Operations#

Sample#

Creates point clouds from fitted models:

  1. Select one or more models in the Object Browser

  2. Click Sample

  3. Configure sampling parameters:

    Sampling Method:

    • Points: Generate specified number of points

    • Distance: Generate points with specified average spacing

    Parameters:

    • Sampling: Number of points or point spacing value

    • Offset: Normal-direction offset from surface (useful for particle picking)

  4. Click OK to generate sample points

Mesh Operations#

Repair#

Fixes mesh topology issues and fills holes. Holes are closed, the mesh is remeshed to uniform edge length, and inferred vertices are faired:

  1. Select mesh models to repair

  2. Click Repair

  3. Configure repair parameters:

    Fairing:

    • Smoothness: Balance between anchoring and curvature minimization (0 = stay in place, 1 = full smoothing)

    • Curvature Weight: Higher-order smoothing for curvature continuity

    • Pressure: Normal displacement of inferred vertices

    Hole Filling:

    • Hole Size: Maximum hole area to fill (-1=fill all holes)

  4. Click OK to repair meshes

Remesh#

Improves mesh quality and adjusts triangle density:

  1. Select mesh models to remesh

  2. Click Remesh

  3. Choose remeshing method:

    Edge Length:

    • Edge Length: Target average edge length

    • Iterations: Number of optimization passes

    Vertex Clustering:

    • Radius: Clustering radius for vertex merging

    Quadratic Decimation:

    • Triangles: Target triangle count

    Subdivide:

    • Iterations: Number of subdivision passes

    • Smooth: Use smooth Loop subdivision vs. simple midpoint

  4. Configure method-specific parameters

  5. Click OK to remesh

Use Cases:

  • Edge Length: Create uniform triangle sizes for simulation

  • Vertex Clustering: Quick mesh simplification

  • Quadratic Decimation: High-quality mesh reduction

  • Subdivide: Increase resolution for detailed modeling

Smooth#

Improves mesh quality by smoothing surface.

  1. Select mesh models to smooth

  2. Click Smooth

  3. Choose remeshing method:

    Taubin:

    • Solid smoothing without net shrinkage

    Laplacian:

    • Very smooth mesh but net shrinkage

    Average:

    • Mesh denoising but net shrinkage

    Parameters:

    • Iterations: Number of smoothing iterations (higher is smoother)

  4. Click OK to remesh

Project#

Projects point clouds onto mesh surfaces using ray casting:

  1. Select exactly one mesh model (target surface)

  2. Select one or more point cloud clusters (sources to project)

  3. Click Project

  4. Configure projection settings:

    Projection Method:

    • Cast Normals: Use point normal vectors for ray casting

    • Invert Normals: Reverse normal direction

  5. Click OK to perform projection

Results:

  • Creates new point clouds with projected coordinates

  • Generates updated mesh with projection points integrated

  • Preserves original data while adding projected versions

Fill#

Fills the interior of a closed triangle mesh with regularly spaced points using ray casting:

  1. Select one or more mesh models

  2. Click Fill

Results:

  • Creates a point cloud filling the mesh interior on a regular grid

  • Grid spacing matches the geometry’s sampling rate

Next Steps#

Continue to the Intelligence tab to learn about advanced features like HMFF and membrane segmentation.