Houdini 20.0 Nodes Geometry nodes

Sequence Blend 2.0 geometry node

Morphs though a sequence of 3D shapes, interpolating geometry and attributes.

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Since 16.5

Parameters

Input Blend

Specifies from which input to get the output geometry. Fractional values blend between adjacent inputs. For example, 0.5 blends between the first input (input 0) and the second input (input 1). Keyframe this value or enter an expression to blend the inputs over time.

Attributes

A space-separated list of names/patterns for attributes to interpolate. Attributes that don’t match here are switched instantly when the whole part of the input number changes, rather than smoothly interpolated. The default is *, meaning interpolate all attributes.

Point ID Attribute

If you enter the name of a (string or integer) point attribute here, the node will use the value of this attribute to match up points between the different inputs. For example, using id will match particle points even if some particles are deleted. If this field is blank (or the attribute doesn’t exist), the node uses point numbers to match up points.

Primitive ID Attribute

If you enter the name of a (string or integer) primitive attribute here, the node will use the value of this attribute to match up primitives (for example, volumes) between the different inputs. For example, using name will match volumes in a fluid system even if volumes are reordered. If this field is blank (or the attribute doesn’t exist), the node uses primitive numbers to match up points.

Voxel Blend

Optionally blend voxel data between volumes or VDBs.

None

Do not blend volume data.

By Grid Index

The voxels are matched by absolute voxel number (not spatial position) so matching volumes should have the exact same dimensions.

By Voxel Position

The voxels are matched by their spatial position. The grid of one volume will be extended to include the other volume, which might change the resolution of the grid.

Interpolate Rotation of Normals, Quaternions, and Transforms

Use spherical linear interpolation for smoother transitions of attributes marked as normals, quaternions, and transforms, and for primitive transforms. When this is off, all blends are component-wise, meaning the transition can be abrupt when the input changes.

Interpolation

Interpolation method for blending multiple inputs.

Linear

Data will be linearly interpolated between 2 inputs.

Cubic

Data will be cubically interpolated between 4 inputs where possible.

Subdivision

Data will follow a cubic spline curve, based on subdivision curves, between 4 inputs where possible.

Use Velocity When Interpolating Position

If points have a v (velocity) attribute (for example, computed with the Trail SOP), this cubically interpolates the point position (P attribute) using the velocity (v), and quadratically interpolates the velocity using the point position. When this is on you need to set Timestep to the duration of each blend in seconds.

Timestep

When Use Velocity when Interpolating Position is on, set this to the duration of the blend between any two adjacent inputs in seconds.

Inputs

Connect the geometries you want to blend between to this node’s multi-input in order. You can reorder the inputs in the parameter editor using the input table below this node’s parameters.

Examples

Birdy Example for Sequence Blend geometry node

The different pieces of geometry, all with the same point count and order, are created. Each piece of geometry is fed into the Sequence Blend SOP in a specific order. Then, the Input Blend parameter is used to animate through the three input morphs using an expression.

BlendPUsingv Example for Sequence Blend geometry node

This example shows how you can blend point positions taking into account their velocities, using the Sequence Blend SOP.

BlendPointAttributes Example for Sequence Blend geometry node

This example shows how to blend point attributes using a Sequence Blend SOP.

BlendPrimitiveAttributes Example for Sequence Blend geometry node

This example shows how to blend primitive attributes using a Sequence Blend SOP.

BlendVertexAttributes Example for Sequence Blend geometry node

This example shows how to blend vertex attributes using a Sequence Blend SOP.

See also

Geometry nodes