The Time Blend SOP will cook its input at both the start and end of the closest integer frame. The values are then blended according to the fractional position within the frame.
Optionally, one can also specify that before a start or after an end frame, the first or last geometry should be held.
The Time Blend SOP can be used to change networks that only exist on
whole frame steps into a network with proper intermediate results. This
will only work if the topology of the geometry stays the same from frame
to frame. It then allows for effects like multi-segment motion blur to
correctly infer in between values. One such use is to turn a file sop
foo$F.bgeo into one that is defined smoothly over time.
Hold First Frame
Determines if the first frame should be clamped. If so, any evaluations before this frame value will instead evaluate at this frame value.
Hold Last Frame
Determines if the last frame should be clamped. If so, any evaluations after this frame value will instead evaluate at this frame value.
Float attributes matching this pattern will be blended.
Point ID Attribute
If this integer or string attribute exists, it will be used to find corresponding points in the different blend inputs. For example, using id will allow particle systems to find matching points even if particles are deleted. If it does not exist or is blank, point numbers will be used for the matching.
Primitive ID Attribute
If this integer or string attribute exists, it will be used to find corresponding primitives in the different blend inputs. For example, using name will allow fluid systems to find matching volumes even if volumes are reordered. If it does not exist or is blank, primitive numbers will be used for the matching.
When By Grid Index is selected, matching volumes will blend their data. This is not done by spatial position, but by absolute voxel index.
Smoothly Interpolate Normals, Quaternions, and Transforms
Enables use of spherical linear interpolation to blend attributes marked as normals, quaternions, and transforms, as well as any primitive transforms. If turned off, these types will be blended linearly.
Use Velocity When Interpolating Position
When enabled, the P (position) attribute will be cubically interpolated using the v (velocity) point attribute, and v will be quadratically interpolated using P. You need to set the Time Step parameter to control the contribution of v.