Houdini 20.0 Nodes Geometry nodes

Tet Conform geometry node

Creates a tetrahedral mesh that conforms to a connected mesh as much as possible.

Since 16.0

The Tet Conform SOP creates a tetrahedral mesh that largely conforms to the input mesh. This means that the surface of the tetrahedral mesh conforms to the original surface wherever possible. In places where the input mesh intersects itself, the tetrahedral mesh may not exactly conform to the input triangles and further processing may be required to remove extraneous tetrahedra, however these cases are extremely rare.


Use this SOP instead of the Tetrahedralize SOP to convert surface meshes into solid tetrahedralizations.


High Quality

If disabled, this option produces the simplest tetrahedralization of the input. If enabled, the tetrahedralization is refined exposing the sizing parameters below.


The following parameters control the sizes of generated tetrahedra. Each scale is multiplied by the Base Size, which can be specified manually or computed automatically.

Base Size

If enabled, this option sets the size of the model in the input. This enables the modification of the model without changing the relative scale of the generated tets. If disabled, the base size of the model is determined automatically as the diameter. In this mode, the sizes of generated tets are independent of the global scale of the model. All sizing parameters below as scaled using the manually set or automatically computed Base Size.

Max Tet Scale

This parameter controls the maximum size of individual generated tets. The volume of a regular tetrahedron with side length equal to Max Tet Size sets the maximum volume of resultant tetrahedra.

Local Scaling

Selects the method to control sizes of tetrahedra on the surface of the resulting tetrahedralization. Interior tetrahedra are sized based on sizes interpolated from the surface.


Surface tetrahedra will not be scaled in any particular way.

Use Local Feature Size

Determine the sizes of surface tetrahedra by following the sizes of triangles in the input.

Use Point Attribute

Specify a custom point attribute to guide the sizes of generated tetrahedra.

Use Constant

Set a constant size to surface tetrahedra.

Local Feature Scale

Sets the scale of local features to guide how large tetrahedra should be on the surface. This is the only scale that isn’t multiplied by the Base Size because it scales an already relative quantity – the feature size.

Local Scale Attribute

Sets the scale of surface tetrahedra based on the values of the given point attribute.

Local Scale Constant

Sets the scale of surface tetrahedra to be this constant.


All scales above except Local Feature Scale are multiplied by the Base Size to give the actual size of tetrahedra.

Other Parameters

Preserve Input Geometry

The geometry from the first input is preserved and conforming tetrahedra are added to it. This may be used for example, to keep polygons and isolated points from the first input input in the output.

At Most One Surface Face per Tet

This option ensures that each tet contributes at most one triangular face to the surface of the tet mesh; distinct triangles on the tet mesh surface cannot be faces of a single tet. This option is useful when you want to preserve vertex attributes such as uv coordinates on a tet mesh.

Output Surface Triangles

Generate output surface triangles that are fused to the generated tetrahedra.

Allow Surface Modifications

Allow for the tetrahedralization add points on the surface to subdivide input polygons.

Use SDF for Cavity Filling

This parameter uses an underlying SDF voxelization of the input mesh to guide which parts of the tetrahedral mesh are to be considered interior. The underlying SDF is eroded by one voxel, so it doesn’t affect how the tet mesh conforms to the surface – only the interior of the mesh i corrected by the SDF. This option is particularly useful when the input mesh contains small cavities that should be filled with tets. For instance, if an input character model that has a small opening in the mouth, without this option the mouth may be missing tetrahedrons. Use this option to close subtle holes in the mesh.

Voxel Size

This parameter sets the voxel size of the underlying SDF used to determine the inside and outside of the solid represented by the input mesh. A lower value will produce a better approximation at a performance cost.

Inserted Point Group

This is the name of an optional point group that is generated by Tet Conform to indicate all the points that were inserted to the first input geometry. This point group contains all points that were added to create higher quality tets. It also contains the points from the second input that were inserted. This output point group is useful for identifying all points that were not present in Tet Conform’s first input.

See also

Geometry nodes