NotchTo Commands

This topic describes the following NotchTo commands:

• NotchToErrors
• NotchToPolygons
• NotchToEdges

Input: DV layer (containing polygons)

Constraint (operator and positive real number)

Measurement region qualifier (optional)

Orientation Qualifiers (optional)

Adjacent Edge qualifier (optional)

Raw/Merged qualifier (optional)

Output: DV layer – Type varies with the command. NotchToErrors outputs a DV layer containing error clusters. NotchToPolygons outputs a DV layer containing polygons. NotchToEdges outputs a DV layer containing edges.

Description: Checks notch width of individual geometry. Notch width is the distance between facing, outside edges on the same geometry. This is an edge to edge check, not corner to corner, or corner to edge.

Edges are considered to face each other for notch checking only if the angle between the outsides of the edges is less than 180 degrees. Collinear edges are not considered facing.

Angles between outside edges:

The arrows in the following figures indicate the edge pairs that are checked when using default orientation and adjacent qualifiers: Acute Also, Not Obtuse, Parallel Also, Not Perpendicular, and Not Adjacent.

• NotchToErrors results are clusters of segments that meet the specified constraints. Each error segment indicates the part of the geometry edge that meets the constraint. The error clusters are returned in a DV layer. The heavy lines in the following example show the portions of edges that are returned as one error cluster.

  

• NotchToPolygons results are polygons that have at least one edge pair that meets the specified constraints. The polygons are returned in a DV layer. The entire polygon in the following example is returned.

  

• NotchToEdges results are segments of edges that meet the specified constraints. These segments retain information about the polygon they are created from. This information allows the edges to be used as input to other DV commands. The segments are returned in a DV layer. The heavy lines in the following example show the segments that are returned as edges. They are not clustered. They retain information about the directions inside and outside of the polygon and sibling relationship.

  

The constraint amount may be given with or without units. If no units are specified the current default length units are used.

Supported operators:

< Less than

<= Less than or equal to

== Equal to

> Greater than

>= Greater than or equal to

Qualifiers may be specified to constrain the edges checked. The defaults, if qualifiers are not specified, are Round (measurement region), Acute Also, Not Obtuse, Parallel Also, Not Perpendicular, Not Adjacent, and Merged (geometry).

Example (JScript):

var layer1 = DVChecker.ImportLayer("trace");

var notchLayer1 = DVChecker.NotchToErrors(Array("<", 5), layer1,

Array("Round", "Acute Also", "Not Obtuse", "Parallel Also", "Not Perpendicular",

"Adjacent Also", "Merged"));

DVChecker.SaveLayer(notchLayer1, "notch errors", "notch < 5 on trace layer");

Measurement Region Qualifier

Measurement region qualifier specifies the construction of the region used to test the constraint. There exist the following choices:

• Round: Forms a region with quarter-circle boundaries that extend past the corners of the edge by the constraint distance. Round is the default region, if no region is specified.

  

• Square: Forms a region with right-angle boundaries that extend past the corners of the edge by the constraint distance.

  

• Opposite: Forms a region with right-angle boundaries that do not extend past the corners of the edge.

  

Measurement Region Use To Check Constraint

The following figure displays the returned segment for error or edge output, marked in blue, and the measurement regions, marked in red and green, that are used to check the constraint.

Orientation Qualifiers

Orientation qualifiers specify edge or angle orientations that qualify edges to be checked against each other. Up to one choice from each of the following four groups may be used:

• Acute Also
• Obtuse Also
• Not Parallel
• Not Acute

If multiple choices from any of the groups are used, the last choice on the group is used. It replaces any earlier choices of that group in the command.

NotchToErrors(Array(“<”, 5), layer, Array(“Acute Also, Obtuse Also, Not Parallel, Not Acute));

is interpreted as:

NotchToErrors(Array(“<”, 5), layer, Array(“Obtuse Also, Not Parallel, Not Acute));

If a choice contains “Only”, that is the only orientation qualifier recognized. Any other orientation qualifiers before or after the first “Only” is ignored.

NotchToErrors(Array(“<”, “5mm”), layer, Array(“Acute Also, Obtuse Only, Not Parallel, Perpendicular Only));

is interpreted as:

NotchToErrors(Array(“<”, “5mm”), layer, Array(“Obtuse Only));

Acute filter

• Acute Also – Include the measurement of edges that have an angle between them greater than 0 and less than 90 degrees. Default if none specified.
• Acute Only – Measure only edges that have an angle between them greater than 0 and less than 90 degrees.
• Not Acute – Do not measure edges that have an angle between them of greater than 0 and less than 90 degrees.

Obtuse filter

• Obtuse Also – Include the measurement of edges that have an angle between them of greater than 90 and less than 180 degrees.
• Obtuse Only – Measure only edges that have an angle between them of greater than 90 and less than 180 degrees.
• Not Obtuse – Do not measure edges that have an angle between them of greater than 90 and less than 180 degrees. Default if none specified.

Parallel filter

• Parallel Also – Include the measurement of parallel edges and non-parallel edges. Default if none specified.
• Parallel Only – Measure only parallel edges.
• Not Parallel – Do not measure parallel edges.

Perpendicular filter

• Perpendicular Also – Include the measurement of perpendicular edges and edges of other orientations.
• Perpendicular Only – Measure only perpendicular edges.
• Not Perpendicular – Do not measure perpendicular edges. Default if none specified.

Adjacent Edge Qualifier

Adjacent Edge qualifier determines if two adjacent edges are checked against each other. Adjacent edges are edges that share at least one point. This qualifier is used in conjunction with the orientation qualifiers to determine which edges to check. One of the three choices may be specified.

• Adjacent Also – Check applies to both adjacent and other edges.
• Adjacent Only – Check only applies to adjacent edges.
• Not Adjacent – Check does not apply to adjacent edges. Default if none specified.

The arrows in the following figure indicate the edge pairs checked using Adjacent Only with the other qualifiers defaulted (Acute Also, Not Obtuse, Parallel Also, Not Perpendicular, and Adjacent Only).

Raw/Merged Qualifier

The Raw/Merged qualifier applies to a DV layer created using the ImportLayer command. Raw specifies the geometry is to be used without first being merged. In contrast, the default setting of Merged specifies the geometry is merged prior to its use.

The arrows in the following figures indicate the edge pairs checked using Raw versus Merged with the other qualifiers defaulted (Acute Also, Not Obtuse, Parallel Also, Not Perpendicular, Not Intersecting).