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If inputs have different numbers of points/primitives, the "extra" geometry will remain stationary during the blend and then disappear when the whole part of the Input blend number changes.
Inputs are numbered from 0, so in the Input blend parameter the first input is 0, second input is 1, and so on.
If an input is not polygonal, instead of blending, the geometry will instantly change when the whole part of the Input blend number changes.
Input blend values higher than the number of inputs (minus 1) simply output the highest input. For example, if you have 3 inputs, any value of
2.0or higher outputs the geometry from the third input.
This node only interpolates attributes that match the pattern(s) in the Attributes parameter. Other attributes maintain their values and switch when the whole part input number changes (for example, it uses the value of un-interpolated attributes from input 0 when the Input blend value is
0.9, and switches to the values from input 1 when Input blend is
1.0). All attributes are interpolated by default.
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.
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.
Do not blend volume data.
By Grid Index
Blend voxel data between volumes. The voxels are matched by absolute voxel number (not spatial position) so matching volumes should have the exact same dimensions.
Smoothly Interpolate 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 linear, meaning the transition can be abrupt when the input changes.
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.
When Use Velocity when Interpolating Position is on, set this to the duration of the blend between any two adjacent inputs in seconds.
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.
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.
This example shows how you can blend point positions taking into account their velocities, using the Sequence Blend SOP.
This example shows how to blend point attributes using a Sequence Blend SOP.
This example shows how to blend primitive attributes using a Sequence Blend SOP.