A frequent question that we get is how to take Area or Perimeter measurements on a curved or irregular shape, like a freeform pool or lawn area.
Revu allows you to create curves using the Polyline and Polygon tools – because the Perimeter tool is a polyline and the Area tool is a polygon, you can create curved measurements. (By the way, the Cloud tool is also a polygon.)
There are a few different ways to create curves. Existing control points or line segments can be converted to curves, or you can use a keyboard shortcut to draw curves directly. Because there are many different types of markups that support curves, I will only use the term “polyline” below, but remember that they apply to all of the aforementioned markup types.
The easiest way to start making a curve is to create a polyline and then convert the Control Points (the yellow handles at each point on the polyline) or line segments to curves.
Converting a line segment to a curve:
Right-click on a line segment in a polyline, then click Convert to Arc . Two new control points will display. These new handles are how you control both the direction and the curve of the arc.
Stretch the handle away from the control point to stretch the curve.
Rotate the handle to change the angle of the curve as it leaves the control point.
If you convert two adjacent line segments, there will be two handles on that control point which control the curve on either side of the point. These handles can be rotated independently, allowing you to have a curve on one side of the point and a straight line on the other.
The below shows a polyline, then the same polyline after the right line segment is converted, and finally the curve after the handles have been moved.
Converting a Control Point:
Right-click on a control point, click Control Point, then Convert .
Converting a Control Point is different than converting a line segment because the two handles will be locked together – rotating one handle will also rotate the other. This allows you to create a smooth curve on each side of this point.
- On the Control Point toolbar, click Convert Control Point .
- Hold the Ctrl key down and click on the control point.
The images below show the same polyline that was used above, but this time the upper right control point was converted and then the handles moved to change the curve.
You can also draw curves directly on the PDF by holding down the Ctrl key and then clicking and dragging each line segment. Drawing curves is a little more complicated, so remember that you can still change the curves after you finish drawing.
This brings us back to measuring curved areas. Everything that you did above can be done with Area and Perimeter measurements.
The images below show the progression of how an Area measurement is created for a freeform lawn. First, a series of points are defined. In this case, we defined 10 points.
Next, the Control Points and a few line segments are converted around the patio. A few curves are almost exactly where they need to be, but some, like the one in the upper right-hand corner, need to be adjusted. The final step is to make adjustments using the curve handles so the final curves match the outline.
Please check out the video tutorial on creating curves in polygons and polylines .