# Page 2: Curves

- Figure 1 - Blank Curves

Purpose: CAD curves are used in various interfaces of LS-PrePost for purposes such as mesh generation and mesh trimming. The curves interface provides a way of managing curve data with functions such as importing, saving, blanking from display, creation, modification, and deletion.

- Blank - Blank curves displayed on the screen. Curves can be selected by picking them individually or by selecting by area. (see Figure 1)

Blank all curves

Unblank all curves

Reverse operation

- Show Pts - Show connection points of curves (points can be used to define additional curves or to perform additional operations on curves)
- Label - Show curve labels

Pop up curves ID list

Project selected curves onto a clean 2D sketchboard

Exit curves data interface

- Figure 2 - Create Curves

- Create - Create a curve by picking points or nodes. Curves can be piecewise or smooth where a fitting function is used to create a smooth curve between all points chosen. (see Figure 2)

- Type: Select curve type (Piecewise curve, Smooth curve, Arc, Circle, Shell intersect)
- ID: Enter unique curve ID
- Name: Assign name to curve

*Arc Options:*

- 3Ps - Pick 3 points
- C/2Ps - Pick center and 2 points in plane

- Radii: Displays radius of arc once it's created

*Circle Options:*

- 3Ps - Pick 3 points
- C/2Ps - Pick center and 2 points in plane
- C/P/R - Define center, plane, and radius

- C: Enter center X/Y/Z
- PN: Enter plane normal vector
- Radii: Enter radius value

*Shell intersect Options:*

- Use the General Selction interface (bottom panel) to select shell parts. Curves will be generated at their intersection.

Apply creation/deletion of curves to database

- Figure 3 - Modify Curves

- Modify - Edit existing curves data (see Figure 3)

- Operation: Select curve operation type
- (Break, Join, Rename, Delete Points, Insert Points, Translate, Rotate, Smooth, Respace)

*Break Curve Options:*

- New Curve Name: Enter new curve name

- At point - break curve at existing point
- At pick - break curve at picked location
- Auto-break - automatically break curve at specified angle
- By curve - break curve with another curve
- By plane - break curve with a plane

*Join Curve Options:*

Clear pick points from curve

- Join Multiple - join multiple curves automatically
- Max.Dist: enter distance between curves to be joined

Apply auto join

Update auto join tolerance based on selection

*Rename Curve Options:*

- New Curve Name: Enter new curve name

*Insert Points Options:*

- Pick line segment - Pick line segment on curve for new data to be inserted

- New point position: Enter new data point x,y,z (press
*Enter*to accept)

*Translate Curve Options:*

Call

- X: Enter X component of direction vector
- Y: Enter Y component of direction vector
- Z: Enter Z component of direction vector

- Distance: Enter distance for translation

- Copy - Translate a copy of the curve

Apply negative translation to curve

Apply positive translation to curve

- Name: Enter name for new curve when
*Copy*is activate

*Rotate Curve Options:*

Call

- X: Enter X component of rotation axis vector
- Y: Enter Y component of rotation axis vector
- Z: Enter Z component of rotation axis vector

- Angle: Enter angle for rotation

- Pick a Origin - Pick origin for rotation
- XYZ: Enter xyz for origin of rotation

- Copy - Rotate a copy of the curve

Apply negative rotation to curve

Apply positive rotation to curve

- Name: Enter name for new curve when
*Copy*is activate

*Smooth Curve Options:*

- Copy - Smooth a copy of the curve

Apply smoothing operation

*Respace Curve Options:*

- Bias - Define biasing for respaced curve

- By Number - Respace by number of segments
- By Size - Respace by segment size

Accept curve modifications

Reject curve modifications

- Figure 4 - Delete Curves

- Delete - Delete Curves (see Figure 4)

Apply creation/deletion of curves to database

Reject deletion of curve(s)

- Figure 5 - RD/WT Curves

- RD/WT - Read/Write curves data in various formats (see Figure 5)

- Type: Select curve data type (IGES, VDA, XYZ, DXF, Define Trim 3D)

- Filename: Enter filename to read/write

Perfrom read curves

Perfrom write curves

- Length - Calculate curve length