Houdini 20.0 Nodes Geometry nodes

FEM Validate geometry node

Visualizes the quality of a tetrahedral mesh.

Since 18.5

To achieve the best results and the best performance with FEM, it is important that your input mesh is good quality. A mesh is good quality when its tetrahedrons resemble regular tetrahedrons and its triangles resemble equilateral triangles. A good quality mesh should also have no inverted tetrahedrons.

The FEM Validate SOP allows you to check your initial geometry before you send it to an FEM simulation. This node lets you:

With this quality feedback, you can eliminate or improve poor quality tets by adjusting the settings of upstream nodes like the Remesh SOP, Tet Conform SOP, and the Tet Embed SOP.

When importing a tetrahedral mesh from another package, its winding order may be the opposite to the one used by Houdini. If you encounter this, then you can use a Reverse SOP to correct the mesh’s winding order.

Example: Quality visualization of a tetrahedral mesh



Limit the geometry that is to be validated to this group.


Allow choice between visualization of mesh quality and tet inversions.

View Slice

Look at a slice of the tet mesh to see the tets on the interior.


Quality Threshold

A quality threshold value between 0 and 1; All tets and polygons below this value will be colored red, all above are colored green.

Isolate Primitives Below Threshold

Show only the primitives below the specified quality threshold.


Position Type

The position attribute used to determine whether a tet is inverted: Material means that the materialP attribute is used. Current means that the current position attribute P is used.

Isolate Inverted

Show only the primitives that are inverted.

Slice Settings


The origin of the clipping plane.


The distance of the clipping plane from the origin in the direction of the normal.


The normal direction of the clipping plane.

Geometry nodes