StartPointType Property
Applies To
Vision Objects: Contour, Edge, Line, LineInspector
Description
Specifies the type of start point to use for an Edge, Line, or LineInspector object. In most cases the start point type will be a point (which usually means the PixelX and PixelY position of the StartPointObject). However, when the StartPointObject for the current line is a 2nd Line object, the StartPointType property is used to define an intersection point on the 2nd line such as the lines midpoint, endpoint, startpoint or perpendicular position.
Usage
VGet Sequence.Object.StartPointType, var
VSet Sequence.Object.StartPointType, value
- Sequence
- Name of a sequence or string variable containing a sequence name.
- Object
- Name of an object or string variable containing an object name. The object must exist in the specified sequence.
- var
- Integer variable that will contain the value of the property.
- value
- Integer value or expression for the new value of the property.
Values
| StartPointObject = Line or LineFinder | StartPointObject = Screen, Geometric, Correlation, Blob, Edge, Polar, BoxFinder, CornerFinder, LineInspector, ArcFinder, DefectFinder, Point or Contour object |
|---|---|
| See remarks. Default: 2 - MidPoint | 0 - Point When using the above objects, the StartPointType can only be of type 0 - Point. |
Remarks
As you can see in the Values Table above, most of the StartPointObject's support only 1 StartPointType called 0-Point. This is because most StartPointObject's use the PixelX and PixelY position for a reference position for defining a start or end point for a line. So when the StartPointObject is defined as Screen, Blob, Correlation, Edge, or Point object the StartPointType will always be set to 0-Point.
The range of valid values for StartPointType depend on the StartPointObject.
However, when the StartPointObject is another Line object, or a LineFinder object, the user must decide where on the 2nd line to intersect with the 1st line. The choices are as follows:
- 1 - EndPoint
- Vision constant: VISION_STARTPNTTYPE_ENDPOINT
- Use the end point of the other line as the start point for this line.
- 2 - MidPoint
- Vision constant: VISION_STARTPNTTYPE_MIDPOINT
- Use the mid point of the other line as the start point for this line.
- 3 - PerpToLine
- Vision constant: VISION_STARTPNTTYPE_PERPTOLINE
- Calculate the position on the 2nd line where the 2 lines intersect in a perpendicular fashion and use this position as the start point.
- 4 - StartPoint
- Vision constant: VISION_STARTPNTTYPE_STARTPOINT
- Use the start point of the other line as the start point for this line.
- 5 - PerpToStartPoint
- Vision constant: VISION_STARTPNTTYPE_PERPTOSTARTPOINT
- Calculate the position on the 2nd line where the 2 lines intersect in a perpendicular fashion through the start point of the first line and use this position as the start point.
- 6 - PerpToMidPoint
- Vision constant: VISION_STARTPNTTYPE_PERPTOMIDPOINT
- Calculate the position on the 2nd line where the 2 lines intersect in a perpendicular fashion through the mid point of the first line and use this position as the start point.
- 7 - PerpToEndPoint
- Vision constant: VISION_STARTPNTTYPE_PERPTOENDPOINT
- Calculate the position on the 2nd line where the 2 lines intersect in a perpendicular fashion through the end point of the first line and use this position as the start point.
If the StartPointObject is changed to a Line object or LineFinder object then the StartPointType is automatically changed to MidPoint.
If the StartPointObject is modified to Screen, Geometric, Correlation, Blob, Edge, Polar, BoxFinder, CornerFinder, LineInspector, ArcFinder, DefectFinder, Point or Contour object, then the StartPointType is automatically changed to “0-Point”.
See Also
Contour Object, Edge Object, EndPointType Property, Line Object, LineFinder Object, LineInspector Object, StartPointObject Property