Objective:

Learn the different methods available for creating surface meshes. If you are looking for how to create a surface mesh, go here. 

Applies to:

• Exporting, design analysis, topology optimization, manufacturing

Procedure:

Mesh from Implicit Body

Mesh from CAD Body

Voxel Grid from Implicit and Mesh from Voxel Grid

Mesh from Implicit Body by Voxels

Extract Volume Mesh Boundary

Quadrangulate Mesh

 

There are three kinds of meshing blocks in nTopology. Surface meshes, solid meshes, and Finite Element (FE) meshes. Note that in nTop we refer to surface meshes as simply ‘meshes’, while volume meshes are specified as volume or solid meshes.

Typically meshes start as a surface mesh, get refined, and can be converted to solid and FE meshes depending on your goal. If you want to export your mesh, you can keep it as a surface mesh, but if you want to analyze it in nTop or another program, you will need to create a volume mesh and then an FE volume mesh. 

 

Mesh from Implicit Body:

Convert an implicit body to a surface mesh.

Pros	Cons
Captures sharp features.	Can have self-intersections depending on the geometry. Typically requires further refinement.

 

The feature size input of this block should be less than the minimum feature size you want to capture in your implicit body. Since all future meshes will be based on this, you should consider using a very small feature size for intricate implicit bodies, and then remesh to a coarser mesh later. The adaptivity input takes in a number greater than 0, which controls if mesh elements will increase in size over flat areas. Low values will result in a more uniform and accurate mesh, while larger values will result in lower element counts. 

 

Mesh from CAD Body:

Convert CAD Body to a surface mesh.

Pros	Cons
Discretizes CAD geometry when implicit nTop geometry is not required.	If the imported CAD part has errors or holes, this may cause issues with the resulting mesh. Typically requires further refinement.

 

Voxel Grid from Implicit and Mesh from Voxel Grid:

Convert voxel grid to a surface mesh and an implicit body into a voxel grid. 

Pros	Cons
Creates a watertight surface body. Usually creates a cleaner mesh than Mesh from Implicit Body.	Eliminates sharp edges to a tolerance.

 

 

Mesh from Implicit Body by Voxels (beta):

Convert an implicit body to a surface mesh using voxels.

Pros	Cons
Very robust and useful for capturing detail in complex parts Captures details on TPMS and lattices well Creates a high-quality mesh Can be exported without further refinement	Eliminates sharp edges to a tolerance.

 

 

Extract Volume Mesh Boundary:

Reduces a volume mesh to a surface mesh by extracting the outer triangles. 

Pros	Cons
Guarantees no meshing issues such as holes or intersections. Useful for complex parts.	Dependent on the time it takes to generate a tetrahedral mesh.

 

 

Quadrangulate Mesh:

Converts a triangle mesh into a quad mesh by remeshing it.

Pros	Cons
Results can be used to convert to a CAD part.  Ideal for topology optimized parts	Only works on manifold meshes. Meshes may need further refinement before being converted into a Quad mesh. Not for use with lattices or TPMS structures.

 

More on this topic:

• How to create a Surface Mesh
• How to create an FE Mesh
• Methods for refining meshes