Construct Sphere dialog box
There are several ways to construct a sphere using PC-DMIS. The following table lists the various types of constructed spheres, along with their necessary inputs. Some features may require no inputs while others may require five inputs or more. 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 FEATURES |
FEATURE #1: |
FEATURE #2: |
COMMENTS |
Auto Sphere |
- |
- |
- |
- |
See "Auto Sphere Construction". |
Best Fit Sphere |
BF |
At least 5 inputs are needed. |
- |
- |
Constructs a best fit sphere using the given inputs. See the Note below for recommended inputs. |
Best Fit with Recomp Sphere |
BFRE |
At least 5 inputs are needed. (1 must be a point) |
- |
- |
Constructs a best fit sphere using the given inputs. See the Note below for recommended inputs. |
Cast Sphere |
CAST |
1 |
Any |
- |
Constructs a sphere at the centroid of the input feature. |
Projected Sphere |
PROJ |
1 or 2 |
Any |
Plane |
One input feature will project the sphere to the workplane. |
Reverse Sphere |
REV |
1 |
Sphere |
- |
Constructs a sphere with a reversed vector. |
Extracted Sphere |
EXTRACTED_SPHERE |
1 |
COP or Mesh |
- |
Constructs an extracted sphere from the COP or Mesh object at the specified diameter or height. |
For Best Fit (BF) or Best Fit Recompensate (BFRE) constructions, while you can use any feature type for your input features, BF and BFRE fit types are typically used with point features or point sets (a scan of points, a feature set with points, or an expression that resolves to an array of points).
If you select inappropriate feature types, PC-DMIS displays this message on the Status bar:
"Cannot construct [feature]. Combination of input features not accepted."
To construct a sphere:
Open the Construct Sphere dialog box (Insert | Feature | Constructed | Sphere).
From the Method list, select the method of the constructed sphere. The available options are:
Auto Sphere
Best Fit
Best Fit Recompensate Sphere
Projected Sphere
Cast Sphere
Reversed direction Sphere
Extracted Sphere
If you select the Best Fit or the BF Recomp (Best Fit Recomp) method for this feature, PC-DMIS allows you to click the Select All Hits button to create the construction from the individual hits of the input features instead of their centroids.
To do this:
From the Feature list, select the feature or features that you want to use to create the constructed feature.
Example showing a selected feature prior to clicking the Select All Hits button
Click the Select All Hits button to display all the components that comprise the selected feature or features.
Display of items that make up the selected feature are highlighted in the dialog box and in the Graphic Display window
PC-DMIS displays and highlights all the components of the selected feature (or features) in the Feature list of the dialog box. You can select or de-select any of the features or feature components shown in the list to include or exclude them.
Click the Create button to create the Constructed feature based on the final features and feature components that you selected.
Constructed feature created based on selected items from the Feature list
Use the table above to select the features from the Feature list based on the selected method.
Select the In or Out option. For details, see the "In / Out Sphere" topic in this documentation.
If you selected either the Best Fit or Best Fit Recompensate methods, from the Best Fit Type list, select the type of best fit algorithm to use. For details, see the "Best Fit Type" topic in this documentation.
If you want to change the feature theoretical values, select the Feature theoreticals check box and type in the values. For details, see the "Specifying Feature Theoreticals" topic in the PC-DMIS Core documentation.
Click the Create button.
The Edit window command line for a sample Sphere Construction
would read:
feature_name=FEAT/SPHERE,TOG1,TOG4
THEO/x_cord,y_cord,z_cord,i_vec,j_vec,k_vec,diam
ACTL/x_cord,y_cord,z_cord,i_vec,j_vec,k_vec,diam
CONSTR/TOG2,TOG3
The actual Edit report displays in all capital letters.
TOG1= POLR or RECT
TOG2 = SPHERE
TOG3 = BF / BFRE / CAST / PROJ / REV
TOG4 = IN / OUT
The first three lines that display in the Edit window are the same for constructed spheres. The fourth line is slightly different, according to the type of feature you are constructing. To switch between the different types of spheres, 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 sphere using the input feature(s). See "Auto Sphere Construction".
The following topics describe the available options for constructing a sphere.
More:
Constructing a Best Fit or Best Fit Recompensate
Constructing a Projected Sphere