Constructing a Point Feature

Construct Point dialog box

There are a number of ways to use PC-DMIS to construct a point. The following table lists the various types of constructed points along with their necessary inputs. Some features may require no inputs while others may require three inputs or more. In the table, the term "Any" indicates that the construction can take any type of feature as input for construction. PC-DMIS allows the features to be selected in any order.

CONSTRUCT FEATURE TYPE	SYMBOL IN EDIT WINDOW	# OF INPUT FEATS	FEAT #1:	FEAT #2:	FEAT #3:	COMMENTS
Auto Point	-	-	-	-	-	See "Auto Point Construction".
Cast Point	CAST	1	Any	-	-	Constructs a point at the centroid of the input feature.
Corner Point	CORNER	3	Plane	Plane	Plane	Constructs a point at the intersection of three planes.
Drop Point	DROP	2	Any	Cone, Cylinder, Line, Slot	-	First feature is dropped onto the second line feature.
Intersect Point	INTOF	2	See topic below for valid features. See topic for valid features.	See topic below for valid features. See topic for valid features.	-	Constructs a point at the intersection of the linear attribute of two features.
Mid Point	MID	2	Any	Any	-	Constructs a mid point between the centroids of the inputs.
Offset Point	OFFSET	1	Any	-	-	Requires three offsets corresponding to X,Y, and Z.
Origin Point	ORIGIN	0	-	-	-	Constructs a point at the alignment origin.
Pierce Point	PIERCE	2	See topic below for valid features. See topic for valid features.	See topic below for valid features. See topic for valid features.	-	Constructs a point where one feature pierces the surface of another feature.
Vector Distance Point	VECT_DIST	2	Any	Any	-	Constructs a point at a distance from the second feature along the line from the two input features.
Project Point	PROJ	1 or 2	Any	Plane	-	One input feature will project the point to the workplane.
Tertiary Datum Point	TERTIARY_DATUM	1	Point, Plane, Line, Set of Points	(Additional Point features if first feature is a point)	(Additional Point features if first feature is a point)	Constructs a point which simulates a tertiary datum that is external to material.

If you select inappropriate feature types, PC-DMIS displays "Cannot construct [feature]. Combination of input features not accepted." on the status bar.

To construct a point, do the following:

Open the Construct Point dialog box (Insert | Feature | Constructed | Point).
Enter the desired features.
Select the method of construction:

Cast Point
Corner Point
Drop Point
Intersect Point
Mid Point
Offset Point
Origin Point
Pierce Point
Vector Distance Point
Project Point
Tertiary Datum

Click the Create button.

The Edit window command line for a sample point construction would read:

feature_name=FEAT/POINT,TOG1
THEO/x_cord,y_cord,z_cord,i_vec,j_vec,k_vec
ACTL/x_cord,y_cord,z_cord,i_vec,j_vec,k_vec
CONSTR/TOG2,TOG3,......

The actual Edit report displays in all capital letters.

TOG1= POLR or RECT

TOG2 = POINT

TOG3 = CAST / CORNER / DROP / INTOF / MID / OFFSET / ORIG / PIERCE / PROJ / TERTIARY_DATUM

The first three lines that display in the Edit window are the same for all constructed points. The fourth line is slightly different according to the type of feature you are constructing. To switch between the different types of points, place the cursor on TOG3 and press F7 or F8. (See "Command Mode Keyboard Functions" in the "Using the Edit Window" chapter.)

When two or more features are involved, PC-DMIS automatically determines the necessary order of the input features. This improves the accuracy of the measurement process.

AUTO is the default method of construction. This option automatically determines the best way to construct a point using the input feature or features. See "Auto Point Construction".

The following topics describe the options for constructing a point.

Auto Point Construction

Constructing an Intersect Point

Constructing a Point at the Origin

Constructing a Drop Point

Constructing a Cast Point

Constructing a Mid Point

Constructing a Corner Point

Constructing a Projected Point

Constructing a Pierce Point

Constructing a Vector Distance Point

Constructing an Offset Point

Constructing a Tertiary Datum Point