EvalViewer cloud Workflow example 1

You are a designer. Someone gives you a file from a 3D scanner and says, "Here...create a finished product design that closely represents this shape (with a prescribed list of criteria or modifications)."

This example will show you how to get section data you can work with. (Explanations of menu choices are found in the reference section of this book.)

A Basic Steinbichler/Hymarc Workflow for converting clouds to XYZ sections:

1 Double-click the EvalViewer icon.

2 Choose File > Open. Select all the relevant files for the job. Check the Memory Total. This total must be less than the capacity of your machine. (To determine this capacity on an SGI workstation, type hinv and look at Main Memory Size.) Choose OK.

3 Autoscale your display to the graphics window using the Look At button.

4 Holding down the left mouse button, rotate the cloud data to see how it looks. Choose the menu Clouds > Quick-Render Cloud. View the cloud from various angles to check its integrity.

Note: If the cloud does not quick-render into a recognizable picture of your part, use Cloud Sections > Unordered Points. Do not compute sections using Cloud > Sections Cuts-Multiple Clouds, because being able to quick-render is a necessary condition for Multiple Cloud Sectioning.

5 If you need to edit out portions of the data set, do the steps in the next section.

Editing out portions of the data set

1 Remove unwanted data with the tabs Subset > Box and Subset > Trace (make sure that tab Subset > Out is selected).

2 When you have finished removing all unwanted data, click the Confirm button.

3 Do another quick-render to verify that you have a good data set. You should now be reasonably satisfied with the data you see.

4 Choose the menu Clouds > Section Cuts > Multiple Clouds. The computer take some time to create the three new section objects. When they appear, hold down the left mouse button and rotate the Section Data to see how it looks.

5 Turn all objects Off with the None button over the Object List. Turn on X sections only by clicking on X Section Object in the object list. Edit the X sections as follows:

To delete any bad points that do not correspond to the shape of the object, use the tab Line > Del Pt.
To break lines if they are misconnected or if you mistakenly join two lines that shouldn't be joined, use tab Line > Del Seg (Delete Segment).
To completely delete any undesired sections or fragments, use tab Line > Del Line.
To connect lines manually, use tab Line > Join. To connect lines automatically, use menu Lines > Combine > Multiple Pass Combine Lines.

When you are finished editing lines, use menu Lines > Reduce Points on Lines.

6 Repeat step 5 for Y sections and Z sections.

Converting clouds to XYZ sections

1 Turn on the X Sections, followed by Y and Z. Use only one set at a time by clicking on its name in the object list.

2 Choose the tab Color > Ran (Random Colors). Each connected line is a single color.

3 Remove unsatisfactory fragments, points, or lines by choosing the Sections tab:

To remove any line fragments that are noisy or have zig-zags, use Del Seg. (Use Alt + Shift with the mouse to change the view while in this mode.) Click the Multi-View button when you have finished.
To remove any points that are misconnected or appear spiky on otherwise smooth lines, use Del Pt. (Use Alt + Shift with the mouse to change the view while in this mode.) Click the Multi-View button when you're finished.
To delete any lines that seem unnecessary, use Del Line. (Use Alt + Shift with the mouse to change the view while in this mode.) Click the Multi-View button when you have finished.

4 Using the colored lines to distinguish the location of line breaks, use Join to join lines that are broken. (Use Alt + Shift and the mouse to change the view while in this mode.)

With Join, you need to press the mouse button down on one line and then release on the line to join to. Click the Multi-View button to indicate that you have finished.

5 Choose the menu Lines > Filter > Smooth [1,2,1]. Press the spacebar to repeat this operation until the data looks very smooth. You should not be able to see any significant changes in your lines during the smoothing operations.

6 Choose the menu Lines > Reduce Points on Lines. Point reduction uses 3D chordal deviation tests when determining which points to keep. Continue with Y and Z Sections of the same part. Go back to Start of X Sections.

7 Choose the menu Lines > Group Visible Lines to group all your XYZ sections into one object (if this is desired).

8 Choose File > Save As > Save Lines As > IGES. Give your Output File a name. Click OK.

9 To quit EvalViewer, use File > Exit.

10 Start AutoStudio or SurfaceStudio. Use File > Open or Import > Cloud.

If you are using any other system, go the IGES import section of your program and import the IGES file.

The above workflow could take anywhere from half an hour to three hours (after accessing your cloud data files) to get very clean lines, depending on the quality and amount of your cloud data. Different scanners may require different cleanup operations.