3-D Curve Construction and Editing

[Guest Frank Calderazzo]

How can one edit 3-D curve segments? i.e line length, arc radius, direction. Is there a tutorial on constructing 3-D curves?

[Guest IronKevin]

Hello Frank,

 

I'm sure a tutorial is needed here but some quick tips:

 

Right click the 3D Curve and select Edit.

 

Then pick a point(s), activate the TriBall and edit through drags or entered values.

 

If you pick a segment and use the TriBall it will move the segment and keep the connection to the adjacent segments.

 

Enjoy,

IronKevin

 

 

[Guest Frank Calderazzo]

I tried to construct a 3-D curve by picking on existing geometry. The curve was created according to the browser but the lines don't show on the screen. if the part is selected from the browser, only the anchor shows up. If edit is selected, the points show up but the lines do not. The file is attached.

test curve 3d.ics

[Chris Lohman]

Frank, I believe I'm noticing something odd with the Acis kernel. Please try this:

 

1) Goto Tools/Options/[Parts] Tab and choose the Parasolid Kernel. (Do not just change your block to parasolid)

2) Create a new scene, Drop in a new block and try to create the curve.

 

 

[Chris Lohman]

Are you using Insert "Line" instead of "Spline" ?

 

 

[Chris Lohman]

Insert Line seems to behave in a very odd way. Ignore that Acis verses Step comment if you're using Insert Line.

 

When using Insert Line, the tool wants to go in a particular direction. It doesn't function like a 2 point line would. So if I hit insert line, and then click 2 points that are not in the axist that the tool wants to go in, I end up with a bunch of empty points. I'm trying to figure out what's going on....

 

 

[Guest Frank Calderazzo]

Chris,

 

I did use insert line.

[Chris Lohman]

ok, finally, I may have something. This insert line only wants to go one way no matter what, however, if you hold down [shift] , then pick the first point (keep shift down) then pick the second, it will allow you to create the line in any direction you want to.

 

So does that help? Hold down shift while you're working with it?

 

 

[pdomenicali]

Chris, is this use of shift in making 3d curves documented anywhere? I also need more instruction in this topic.

 

 

Regards,

Peter Domenicali

[Chris Lohman]

Documentation.......

 

None that I can find

 

 

[Guest Frank Calderazzo]

Chris,

Apparently the shift key only works for the first line segment. If you try to chain another straight line it defaults back to the same direction as the first line. I'm disappointed in the implementation of this function. It should work more like 2-D line creation with a drawing grid and the ability to right click, see the dimensions and then edit them. It would also be useful to be able to have a corner blend function. The triball could be used to rotate the grid for each segment.

 

I'm trying to use the function to model piping. The work around is to construct a set of sweep solids.

 

The function needs some programming work. It should be more like the excellent user interface in the rest of the product.

[Chris Lohman]

Frank I found that I had to click on the "pointer" icon to unselect the tool, then reselect the insert line tool, and repeat after each line.

 

I have made the people that decide how stuff works aware of your comments.

 

 

[Guest IronKevin]

5 seconds into the Help system, Index, 3D Curve:

 

To create a 3D curve shape:

 

1. From within an active scene, select the 3D Curve Shape tool from the IntelliShape Creation toolbar.

 

Note that the 3D Curve Tool session bar is activated to the left of the Selection toolbar:

 

 

3D Curve Tool session bar

 

2. Select the desired type of curve (spline, line, or arc) to create by clicking the appropriate button on the session bar. (The spline is selected by default when the tool is activated.)

 

3. Place the first point of the 3D curve by clicking on existing geometry or in 3D space.

 

Note that when placing a 3D curve on existing geometry, by default it will extend perpendicular from the selected geometry. To disable this behavior, depress the Shift key prior to clicking on the geometry.

 

4. Similarly, click the desired location to place the next point of the curve. Continue to click until all desired points are entered.

 

Note that the offset value can be changed to apply an offset distance to specific picks.

 

5. Follow the above process to add additional splines, lines, and/or arcs to the 3D curve.

 

6. Click Apply and Exit to complete creation of the curve in the scene or Exit to return to the scene without completing the curve.

 

 

Editing:

 

To edit a 3D curve shape:

 

Existing 3D curves can be edited by right-clicking on the curve and selecting Edit from the resulting pop-up menu. This activates the edit session, which allows the following capabilities:

 

· Deleting an individual segment by selecting it and then hitting the Delete key or selecting Delete from the right-mouse menu.

 

· Repositioning an entire curve(s) or segment(s) using the TriBall, by first selecting the desired curve(s) and then activating the TriBall.

 

· Repositioning a curve point by dragging on its handle, using the TriBall, or selecting Edit from the right-mouse menu and manually entering coordinates.

 

· Repositioning a curve point(s) using the TriBall, by first selecting them and then activating the TriBall. To move multiple points simultaneously, depress the Shift key, select the desired points, and then activate the TriBall to reposition them.

 

· Repositioning a curve point using the right-mouse pop-up menu to edit its global coordinates.

 

· Offsetting an entire curve or segment(s) by entering the desired value in the Offset field on the 3D curve session bar, and then dragging on point handles on existing geometry.

 

· Adding segments to an existing curve by selecting the desired curve option from the session bar, picking an end point (a change in color from red to yellow of the end point indicates connection), and then following the steps for creating a new curve.

 

· Editing the magnitude of the tangency of a smoothly connected spline, by first clicking on the spline to activate editing handles at each of its endpoints, and then left-clicking and dragging on the desired handle.

 

· Editing the orientation of a smoothly connected spline, by first clicking on the spline to activate editing handles at each of its endpoints, and then right-clicking the desired handle to access the following options for alignment of the tangency to existing geometry: To Point, To Center Point, Point to Point, Parallel to Edge, Perpendicular to Face, and Parallel to Axis. Once the desired option is specified, click on the applicable entity to complete the editing operation.

 

When edits are complete, click Apply and Exit on the 3D Curve Tool session bar to end the operation and return to the scene.

During the editing operation, error feedback is provided when modifications cause invalid states. Problem areas are displayed in red, accompanied by error message dialogs.

To edit curve properties, right-click the curve in the scene and select 3D Curve Properties from the resulting pop-up menu. Select the 3D Curve tab to access display of the selected curves overall length. Select the General tab to access the kernel type for the selected curve shape. (Control-K toggles between the kernel types in the scene.)

 

respectful

[Cary OConnor]

Hi Frank,

Your Enhancement comments on the 3D Curve have been taken into consideration for future releases of IronCAD. We feel that additional creation types and usability need to be offered to support additional functionality that will rely on the 3D Curve. But until we have the enhancements, let me see if I can provide some information about the current 3D Curve Capabilities. Currently when you place your first point using the 3D Curve (line/spline/Arc), if your first point is on existing geometry (i.e. a face of an existing part) the default behavior is to extend perpendicular or normal from the point. Holding the shift key down prior to picking this point will allow the curve to move in any direction from this point on existing geometry. This option is available to provide the ability to extend from existing geometry in a direction that is normal to the point or face. Think of the case when you want to extend an existing pipe with a new one. This option makes it easy to extent the pipe by making a smooth connection with the existing. This option only works on the first placement point in a segment command (i.e. it will work the first time when you turn on and off each segment command (line/Spline/Arc)). The other problem you were experiencing is the smooth connection option when adding line to other lines. The Smooth Connection Icon in the 3D curve Toolbar is on by default. This creates a smooth connection between each line segment so that a continuous curve can be created to allow a valid sweep shape. If you turn off the smooth connection option, the lines will move in any direction when attaching to other lines. Hope this information along with the information posted above can help you out.