FEM Mesh Generation
From CAD geometry to simulation-ready mesh
Overview
Mesh generation converts your 3D parametric geometry into a finite element mesh suitable for simulation. confBuild uses the Netgen mesher to automatically create high-quality tetrahedral meshes from your models.
Key Features
- Automatic mesh generation from parametric 3D models
- Support for all primitive types: box, cylinder, sphere, extrusion, STL
- Configurable mesh fineness from very coarse to very fine
- Linear (TET4) and quadratic (TET10) tetrahedral elements
- Face group detection for boundary condition assignment
- Output in VTK and MED formats
Mesh Quality Settings
Control the mesh density to balance accuracy against computation time.
0
Very Coarse
Fastest computation, lower accuracy
1
Coarse
Quick preliminary analysis
2
Medium
Good balance of speed and accuracy
3
Fine
Higher accuracy, longer computation
4
Very Fine
Maximum accuracy, longest computation
Maximum Element Size
The maximum element size is automatically calculated from the bounding box of your geometry. You can override this value for finer control. Smaller element sizes produce more elements and higher accuracy, but increase computation time.
Element Types
Choose between linear and quadratic tetrahedral elements.
TET4 (Linear)
4 nodes per element, faster
TET10 (Quadratic)
10 nodes per element, more accurate
When to Use Quadratic Elements
- Bending-dominated problems benefit greatly from TET10 elements
- Stress concentrations near holes, notches, or fillets
- When accuracy is more important than computation speed
- Contact problems require better surface representation
Enable quadratic elements by toggling the Second Order option in the FEM mesh panel.
Supported Primitives
The mesher handles all confBuild geometry types.
Box
width, height, depth
Rectangular solid geometry
Cylinder
radiusTop, radiusBottom, height
Includes cones (different radii)
Sphere
radius
Full sphere geometry
Extrusion
2D profile, depth
Extruded 2D cross-sections
STL
mesh data
Fallback for unsupported geometry
Face Groups
Face groups identify mesh surfaces for applying boundary conditions.
Automatic Face Detection
During mesh generation, confBuild automatically detects and labels face groups based on geometric features. For a box, these include:
- Top / Bottom — Upper and lower faces
- Front / Back — Front and rear faces
- Left / Right — Side faces
For cylinders, spheres, and extrusions, face groups are generated based on the topology of the shape. You can view all available face groups in the FEM panel after mesh generation.
Using Face Groups
Each boundary condition is applied to one or more face groups. For example, you might fix the "Bottom" face group and apply a force to the "Top" face group. The AI-assisted BC generator can automatically match face groups to your load case description.
Mesh Generation Pipeline
Understanding the internal mesh generation process.
Extract Primitives
Read geometry data from 3D scene
Build CAD Geometry
Create OpenCASCADE/Salome geometry
Apply Transforms
Position, rotation, scaling
Generate Mesh
Netgen mesher creates tetrahedra
Output Formats
- VTK — Used for visualization in the 3D viewport
- MED — Salome native format, used by Code_Aster solver
- STEP — CAD geometry representation
Best Practices
Tips for generating good simulation meshes.
Recommendations
- Start with a coarse mesh for initial validation, then refine for final results
- Use quadratic (TET10) elements for bending-dominated problems
- Ensure your geometry is watertight — no gaps or overlapping faces
- Check the mesh info panel for vertex count and element count after generation
- For complex assemblies, consider meshing each part separately
Troubleshooting
- Mesh generation fails: Check for degenerate geometry (zero-thickness, self-intersections)
- Too many elements: Reduce fineness or increase max element size
- Poor quality elements: Simplify geometry or increase mesh fineness
- Missing face groups: Ensure geometry has distinct planar faces