Houdini 20.0 Nodes Geometry nodes

Inflate geometry node

Deforms the points in the first input to make room for the inflation tool.

The first input is inflated by taking a number of inflation points. From each inflation point, the surrounding geometry is moved away from the inflation point so as to account for the shape of the inflation tool. The inflation points do not have to be inside the tool geometry, but if they are outside, the tool geometry will be implicitly expanded to contain the inflation points.

If two inputs are given, the second input is the inflation tool. If three are given, the third input is the rest position of the inflation tool. If a rest position is given, the rest inflation points are used to determine sidedness of the inflation points. If the current inflation point is on the other side of the geometry compared to the corresponding rest inflation point, it will be moved back to lie within the geometry. The Min Surf Distance controls this behavior.

For each point to inflate, one single inflation point is calculated and the inflation is done with respect to that point. Instead of, or in addition to, inflation points, inflation primitives may be specified. Closed polygons will be assumed convex and planar, and the inflation point will be the minimum point to the polygon. Open polylines will create an inflation point for the minimum point on each line segment. The set of inflation points found will then be interpolated. Those within Center Overlap of the closest will be blended according to the Blend Exponent.



Points to be affected by the inflation.

Tool Group

The primitives in the inflation tool that will be used as the tool geometry.

Center Group

The points in the inflation tool that will be used as inflation points.

Center Overlap

Controls the width of the band where inflation points will interact.

Blend Exponent

The fall off rate for the Center Overlap.

Min Surf Distance

This is the closest which the current inflation points can get to the first inputs surface, as measured along a line between the rest inflation point and the current inflation point. If disabled, no clipping is done.


This controls the falloff of the inflation. A value of 3 will approximately preserve volume. A value of 2 will preserve area if the inflation is occurring inside a plane.

This parameter can be modified on a per point basis.

Inflate to Farthest

Normally the inflation stops when it hits the first outgoing surface in the tool geometry. This option will cause it to inflate using the farthest intersection. This will produce bad results if the geometry is not convex with respect to the inflation point, but can allow the use of multiple overlapped geometry.

Maximum Inflation Distance

This can be used to minimize the bad effects of Inflate to Farthest when working with non-convex geometry. It specifies the maximum distance which can be considered a valid inflation - any geometry farther than that is ignored.

This parameter can be modified on a per-point basis.

See also

Geometry nodes