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The Resample op works natively with all curve types including polygon, NURBS or Bezier curve inputs. However, for NURBS or Bezier curves the resample SOP will use a polygonal approximation to calculate the length of the curve using the LOD parameter - though the final sample points will still lie on the original curve. Other non-curve geometry will first be converted to polygon curves before resampling.
Inputs / Geometry Types
The Resample op works in conjunction with any primitive type that can be converted to polygons. This includes Bezier curves, NURBS curves, circles, and polygons.
Group of curves of surfaces to resample.
Maintain Primitive Order
This applies when resampling a group that doesn’t contain all primitives. If this checkbox is turned off, resampled primitives are placed after any untouched primitives.
Level of Detail
Level of detail at which to convert non-polygonal inputs.
Resample by Polygon Edge
Each edge of the polygon will be resampled independently. This option will preserve corners in the input.
Even Length Segments
Measure the natural edge length.
Even X Segments
Measure the edges against the X axis.
Even Y Segments
Measure the edges against the Y axis.
Even Z Segments
Measure the edges against the Z axis.
Measure distance along the original curve between resampled points.
Measure distance between resampled points.
Maximum Segment Length
Specify maximum length of resulting edges.
The maximum segment length of resulting edges. If you are working in centimeters, the default is 10. If you are working in meters, the default is 0.1.
Specify the maximum number of edges.
The maximum number of edges.
Allow Primitive Attributes to Override Parameters
If the input contains primitive attributes
num_segments, they will override the Length or Segments parameters. If the value of either is less than or equal to zero, it will behave as if the corresponding toggle is disabled for that primitive.
Even Last Segment Same Length
When enabled, and Method is Even Length Segments, and Maximum Segment Length is enabled, instead of having a last segment that is shorter than the rest, all segments are shrunk slightly, so that they all have the same length.
Maintain Last Vertex
Include final CV of original in resampled polygon.
Randomize First Segment Length
When resampling multiple curves, randomly adjust the first segment length for each curve. The randomly chosen length is based on the curve primitive number. This option can help to eliminate aliasing when using the resample SOP to convert curves to a point cloud.
Create Only Points
Instead of creating new polygon primitives, create only the points on the resampled curve. This option can be faster when only the resulting points are required.
Treat Polygons As
Set this to Subdivision Curves to resample polygons as if they are smooth, subdivision curves, instead of the usual Straight Edges. The Interpolating Curves option will resample them as if they are smooth curves that pass through all of the points in the polygon.
Output as Polygon Curves to be Subdivided Later
This option moves the output points in such a way that if the curves being output will be subdivided later, e.g. in Mantra or the viewport, their subdivided forms should pass through the sampled points. This is particularly useful when downsampling curves to a small number of points before rendering as subdivision curves. Without this option, the shape of the subdivided curves won’t match the original curves as well.
Create a point attribute storing the length of output curve that is closest to each point along the curve. This is half the sum of the lengths of all edges connected to each output point. When creating only points, this value can be used to determine how much of the original curve each point represents.
Create a point attribute storing the normalized curve tangent for each point on the resampled curve. When creating only points, this value can be used to determine the tangent of the original curve at that point.
Curve U Attribute
Create a point attribute storing the unit curve parameter value for the resampled point. This is the value that the input curve would be carved at to get the corresponding output point. Note this depends on the point spacing of the input.
Curve Number Attribute
Create a point attribute storing the curve primitive number for the resampled point.
This example demonstrates the use of the Resample SOP on three types of curves. (Polygon, NURBS and Bezier)
The Resample SOP rebuilds the curve by converting it into a series of Polygon Line Segments.
The curve may be rebuilt “Along Arc” or “Along Chord”. “Along Arc” utilizes the Hull information as a basis of reconstruction, and can be defined by a Maximum Segment Length and/or Maximum Segment number. “Along Chord” can only be defined by Maximum Segment Length.
Resampling the curve based on Maximum Segment number divides the line into segments of equal, but unspecified length, spanning from start to endpoint. Line detail is directly proportional to the Segment number.
Resampling the curve based on Maximum Segment Length will rebuild the entire line into equal length segments except the last segment. If the Maintain Last Vertex option is on, the last segment will be less than or equal to the Maximum Segment Length value, depending on its distance to the endpoint. With the option off, the endpoint is disregarded and the line is created out of equal lengths.
Turn on Points in the display to see how the Resample SOP resamples line segments.