Houdini 20.0 Nodes Geometry nodes

Spline Align geometry node

Aligns a group of primitives to each other or to an auxiliary input.

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Left and Right Primitives

The notions of “left” and “right” which follow depend on context. If an auxiliary input is used, it is always the right primitive and the primary input geometry are all left primitives. If only one input is used, then for each pair being aligned, there is a left and a right primitive. This means that relative to neighboring primitives, one primitive can be both left and right.


Align Source

Any geometry type. Treated as left/right primitive pairs or left primitives if an auxiliary source is used.

Auxiliary Source

Any geometry type consisting of a single primitive treated as the “right” primitive.



Which primitives to align. If blank aligns entire input.

Align To

Which primitive to align to. If blank aligns to first primitive in the auxiliary input.


Can optionally align subgroups of N primitives or patterns of primitives.


Determines the pattern of primitives aligned.



This tab describes the main parameters for alignment.


Determines which primitive remains unaffected. 0 : first 1 : last.

Left UV

Pivot location on the “left” primitive.

Right UV

Pivot location on the “right” primitive.

Right UV End

If an auxiliary input is used, this location specifies an endpoint for the alignment. Primitives are distributed uniformly between the Right UV and the Right UV End.

Individual Alignment

Causes each primitive in the group to be aligned. If off, only the first primitive is aligned and all others are placed relative to it.


Translates primitives during alignment.


Rotates primitives during alignment.



This tab describes the post-alignment transformation in the local alignment space.

Transform Order

Order in which transformations occur.

Rotate Order

Order in which rotations occur.


Amount of translation along local xyz axes.


Amount of rotation about local xyz axes.


Non-uniform scaling along local xyz axes.


Local pivot point for transformations.


AlignTube Example for Spline Align geometry node

This example demonstrates how the UV information on surfaces, NURBS in this example, are used by the Align SOP to orient one object to another’s surface.

UV reference parameters in the Align SOP can be animated as shown in the align_tube example.

Animating UV parameters leads to the translation and rotation of the aligned geometries along one another’s surface in various ways.

See also

Geometry nodes