Dialog: Blend-Curve

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Dialog: Blend-Curve

Blend-Curve

See also Add Blend-Curve

You can edit the X-Y Position of the start-Point and end-Point in the Part-Editor.

You can also edit these geometric-properties AT the start-Point and AT the end-Point of a Blend-Curve :

•Angle

•Curvature

•Curvature Rate  

The geometric-properties are:

•equal to those of the sketch-element(s) with which you merge the Blend-Curve's start-Point and/or end-Point.

OR

•zero(0) if you do not merge the Blend-Curve with sketch-elements at its start-Point and end-Point.

You can edit the geometric-properties

•Exactly : with the Blend-Curve dialog-box

•Approximately : with the Blend-Curve drag-handles.

Edit Exactly

tog_minusHow to open the Blend-Point dialog-box

MD-GA-Blend-Curve-Edit

In the Part-Editor or the Mechanism-Editor:

1.Double-click the Blend-Curve in the graphic-area

- or -

1.See How to Open a Dialog-Box  

The Blend-Curve dialog-box is now open.

tog_minusBlend-Curve dialog-box
MD-Dialog-Blend-Curve-Collapsed

There are two separators:

 Start-Point...

 End-Point...

The parameters are the same for the two separators
MD-Dialog-Blend-Curve-StartPointEnd-Point

 Start Point ...  / End Point ...

Angle (Units: º):

Blend / Free check-box:

☑(DEFAULT) The angle of the Blend-Curve (at its start-Point or end-Point) is equal to the angle of the adjacent sketch-element

❑Edit the angle of the Blend-Curve (at its start-Point or end-Point).

Curvature k (Units:1 ∕ meter):

Blend / Free check-box:

☑(DEFAULT) The curvature of the Blend-Curve (at its start-Point or end-Point) is equal to the curvature of the adjacent sketch-element.

❑Edit the curvature for the Blend-Curve (at its start-Point or end-Point).

Curvature-Rate dk ∕ ds (Units: 1 ∕ m^2):

Blend / Free check-box:

☑The curvature-rate of the Blend-Curve (at the start-Point or end-Point) is equal to the curvature-rate of the adjacent sketch-element

❑(DEFAULT) Edit a curvature-rate for the Blend-Curve (at its start-Point or end-Point).

Velocity Scaling (no units)

Increase Velocity-Scaling to inflate the balloon!

Decrease Velocity-Scaling to deflate the balloon!

Velocity Scaling does not have units.

Default = 1 ; Maximum = 10 ; Minimum 0.01

Edit Approximately

tog_minusTo show / hide the Blend-Curve drag-handles
Drag handles in the Graphic-Area

Drag handles in the Graphic-Area

To show the Drag-Handles

1.Click the Blend-Curve one time

You can now see the Drag-Handles at the start-Point and the end-Point

There are two(2) Drag-Handle types:

Red-14-1 Arrowhead Drag-Handle

Red-14-2 Circle Drag-Point (not easy to see)
tog_minusBlend-Curve Drag-Handles
Arrowhead Drag-Handle

Arrowhead Drag-Handle

Arrowhead Drag-Handles control the Angle and the Velocity-Scaling Factor

1.Double-click an Arrowhead Drag-Handles

The Drag-Handle should now be blue

2.Drag the blue arrowhead relative to the (start or end)-Point:

Red-14-1b Rotate the arrowhead to control the angle of the Blend-Curve.

Red-14-2 Move the arrowhead away to increase the Velocity-Scaling factor
Circle Drag-Handle

Circle Drag-Handle

Circle Drag-Handle control the Curvature

1.Double-click one of the Circle Drag-Handles (not easy to see!)

The Drag-Handle should now be blue (not easy to see!)

At the default position (vertically-up), the Curvature = 0 (a straight-line).

2.Rotate the blue circle around the (start or end)-Point:

Red-14-1b In a clockwise direction to increase the +ve curvature

Red-14-1b In a counter-clockwise direction to increase the –ve curvature

When the Circle is vertically-down the Curvature is a large +ve or –ve value.

Note on Curvature and Curvature-Rate

tog_minusCurvature and Curvature-Rate

Curvature

All positions along a curve have a radius, which we call the curve's Radius-of-Curvature.

Curvature = 1 / Radius-of-Curvature

In general, the Radius-of-Curvature continually changes along the curve.

As Radius-of-Curvature decreases, the Curvature increases.

Curvature of a Line = 0 ; Radius-of-Curvature of a Line = ∞

Curvature of a Circle = 1 ∕ Circle Radius.

E.g. : A circle has a radius of 20mm, its curvature = 1/0.02m = 50/m.

Curvature-Rate

This is the rate-of-change of curvature (how rapidly curvature changes) with respect to the distance along the Blend-Curve.