Cross-Section Surface

Introduction

This topic will explain the Cross-Section Surface function, and the options found in it. This topic will also describe where to find the function, provide quick steps and an example on how to use it, and provide links to related topics.

The Cross-Section Surface Function

The Cross-Section Surface function creates a surface from a group of wireframe curves that are roughly parallel. To perform the function, you chain select each of the cross section entities one at a time, press the Spacebar to confirm the selection, and click OK. You can have as many cross sections as you like, but you must have at least two. The order in which you select the cross sections determines how the surface is created.

 

To open Cross-Section:

 

  • In the Surfaces group, of the Create 3D tab, click Cross-Section.

 

The parameters display in the Data Entry Manager.

The Data Entry Parameters

  • Preview - Select the check box to enable the CAD preview, which displays what the result will be before you create it. Once all geometry is selected, the preview is shown.
    Preview - Clear the check box to turn off the CAD preview.

Selected Geometry

 

(Move Up) - Move the highlighted item up the list.

(Move Down) - Moves the highlighted item down the list.

(Reverse Direction) - Reverses the direction of the highlighted item.

(Delete) - removes the highlighted item from the list.

(Delete All)- removes all entities from the list.
This list box will show the entities currently selected for the function.

 

  • OK - finalizes the function.

  • Cancel - exits the function.

Quick Steps - Cross-Section

When creating a Cross-Section Surface, you complete one chain selection for each cross section. Each chain can be one or more entities. The selection order determines the results, and the chains should all share the same general direction, such as left to right.

 

  1. Open the function.

    The Selected Geometry list automatically has focus.

  2. Chain select the first chain.

     

Tip: To chain select an entire chain at once, use the Auto-Chaining options found in the Picking Manager. To select a portion of a chain, turn off Auto-Chaining and use the Multi-Entity option to click one entity at a time, or Manual Chaining to pick the start and then the continuation, or end, of the chain. With Manual Chaining, the next entity you click will chain to the last entity you selected if possible. In this manner you can control the path manually when branches are present in the chain.

 

  1. Chain select the second chain using the same direction as the first chain.

    With two chains selected, the Preview appears.

  2. Repeat this process until all cross sections of the surface are selected and using the same direction.

    The Preview updates with every new cross section added to the Selected Geometry list.

  3. To create the surface, in the Data Entry Manager, click OK.

    The feature is added to the CAD Tree.

    You can repeat this process for any other surfaces.

  4. To close the function, click Cancel.

Example

This example will demonstrate how to use the Cross Section function.

 

Note: In the images below, both the Show Axis X-Y and Show Gnomon toggles have been disabled in the Axis X-Y group of the Settings Part > Display dialog.


  1. In the quick access toolbar, click Open.

  2. In the Open dialog box, navigate to C:\BobCAD-CAM Data\BobCAD-CAM V**\Examples.

     

Note: This is the default install location. If you performed a custom install, navigate to the location in which you installed the software.


  1. Select cross section surface example.bbcd, and click Open.

    The file opens.



     Leave the file in the ISO 2 view.

  2. In the Surfaces group, of the Create 3D tab, click Cross-Section.

    The Cross Section Surface parameters display in the Data Entry Manager and the Picking Manager appears.

  3. In the Picking Manager, turn off Auto-Chaining and select Manual Chaining.

  4. Highlight the entity as seen in the image below.



  5. Click the entity to set the start of the chain.



  6. Highlight the end of the chain as seen in the image below, and click to continue the chain to this entity.



    The chain continues to the end.



  7. In the Picking Manager, click End Chain.

    The chain is added to the Selected Geometry list.

 

Tip: To end chains, you can also use the contextual toolbar to select the End Chain icon.

 

Tip: To chain select a portion of a chain, as we have done here, click near the end of the first chain entity to set the start of the chain, then hold click near the end of the last entity to set the end of the chain.To select an entire chain at once with Auto-Chaining off, hold Shift and click near the end of the last entity to set the start and end of the chain in one click.

 

Note: While selecting the geometry for a cross-section, you can click the start arrow next to the Selected Geometry list to change the direction of that cross section, or use the Reverse button after highlighting that chain in the Selected Geometry list of the Cross Section Surface parameters in the Data Entry Manager. It is important that all of the cross sections share the same direction.

 

  1. In the Picking Manager, turn on Auto-Chaining, turn off Constant Z, and hover over the end of the next chain, as seen in the image below.



  2. Click the end of the entity to chain select the entire chain.



    With two cross sections added to the Selected Geometry list, the Preview displays.

  3. Repeat step 11 for each of the subsequent chains, in order, until all are added to the Selected Geometry list.



    Notice the difference between the two sides. Even though the last four chains are mirror images of the first four chains, selecting only a portion of the first chain, as we have done, has created some irregularities.

    We will correct that in the next steps.

  4. In the Selected Geometry list, click on Chain-1to highlight it.



    The chain highlights in the graphics area.

  5. Click (Delete) to remove the partial chain from the list.

     

Tip: You can also right-click a chain in the list to gain access to the same controls seen on the buttons.

 

The Preview updates.



  1. Hover over the end of the deselected chain as seen in the image below.



  2. Click the end of the entity to chain select the entire chain.



    The chain is added to the Selected Geometry list as Chain-10 and the Preview updates.

    Because the order of the chains in the Selected Geometry list is wrong, the Preview shows an unintended result. We will correct that in the next steps.

  3. In the Selected Geometry list, click Chain-10 to highlight it.



    The chain highlights in the graphics area.

  4. Click the (Move Up) button to move Chain-10 up the list.



    The Preview updates.

    The order is still off. We need to move Chain-10 to the top of the list.

  5. Click the (Move Up) button to move Chain-10 up the list, until it is at the top of the list.

    The Preview updates.



  6. Click OK to finalize the Cross Section.

    The surface is created and a Cross Section feature is created in the CAD Tree.



  7. To end the function, click Cancel.


 

This concludes the example.

Related Topics

The CAD Overview