## Constructing a Plane Feature

Plane Construction dialog box

There are several methods for constructing a plane using PC-DMIS. The following table lists the various types of constructed planes, along with their necessary inputs. Some features may require no inputs, while others may require three inputs or more. In the following 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
Alignment Plane | ALIGN | 0 | - | - | - | Constructs plane at alignment origin
Best Fit Plane | BF | At least 3 inputs are needed. | - | - | - | Constructs best fit plane using inputs
Best Fit with Recomp Plane | BFRE | At least 3 inputs are needed. (1 must be a point) | - | - | - | Constructs best fit plane using inputs
Cast Plane | CAST | 1 | Any | - | - | Constructs plane at centroid of input feature
High Point Plane | HIPNT | Either 1 set (using a minimum of 3 features) or 1 scan. | If input is a set, use any; if input is a scan, use a Patch scan. |  |  | Constructs plane using the highest available points.
Mid Plane | MID | 2 | Any | Any | - | Constructs mid plane between centroids of the inputs
Offset Plane | OFFSET | 3 or 1 | Any (1 of 3) Or plane feature if only 1 input. | Any (2 of 3) | Any (3 of 3) | Builds plane offset from the input features (or from single plane feature).
Parallel Plane | PLTO | 2 | Any | Any | - | Constructs plane parallel to first feat and passing through second feature
Perpendicular Plane | PRTO | 2 | Line or Axis Element | Any | - | Constructs plane perpendicular to first feature and passing through second feature
Reverse Plane | REV | 1 | Plane | - | - | Constructs plane passing through input with reversed vector

To construct a plane:

1. Select Construct from the menu bar (Insert | Feature | Constructed | Plane).

2. Select Plane. The Construct Plane dialog box will appear.

3. Input the desired features.

4. Select the method of construction. Available options include:

- Alignment Plane

- Best Fit or Best Fit Recompensate Plane

- Cast Plane

- High Point Plane

- Mid Plane

- Offset Plane

- Parallel Plane

- Perpendicular Plane

- Reversed direction Plane

- Auto Plane

5. Click the Create button.

The Edit window command line for a sample Plane Construction would read:
feature_name=FEAT/PLANE,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,......

If TOG2 = PLANE and TOG3 = BF or BFRE then the command has the following format:
feature_name=FEAT/PLANE,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/PLANE,TOG3
OUTLIER_REMOVAL/TOG5,stdDevMultiplier
FILTER/TOG5,WAVELENGTH= cutoffWavelength

Note: The actual Edit report will be displayed in all CAPS.

AUTO is the default method of construction. This option automatically determines the best way to construct a plane using the input feature(s). See "Auto Plane Construction". | TOG1= POLR or RECT TOG2 = PLANE TOG3 = ALIGN / BF / BFRE / CAST / HIPNT / MID / OFFSET / PLTO / PROJ / PRTO / REV TOG5 = ON / OFF stdDevMultiplier = This multiplier value determines whether or not a measured point is an outlier. If the point from the plane is further than the standard deviation multiplied by this, then it is an outlier and will be removed if you have selected the Remove Outlier option.

cutoffWavelength = This value controls the amount of data smoothing. The longer the wavelength the more smoothing there will be.

The first three lines displayed in the Edit window will be the same for constructed planes. The fourth line will be slightly different, according to the type of feature being constructed. You can switch between the different types of planes by placing the cursor on TOG3 and pressing F7 or F8. (See "Command Mode Keyboard Functions" in the "Using the Edit Window" section.)

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.

The following paragraphs describe the available options for constructing a plane:

More:

Constructing a Plane from an Alignment

Constructing a Best Fit or Best Fit Recompensate Plane

Constructing a Cast Plane

Constructing a High Point Plane

Constructing a Mid Plane

Constructing an Offset Plane

Constructing a Parallel Plane

Constructing a Perpendicular Plane

Changing the Direction of a Plane

Auto Plane Construction