Drawing Curved Lines with the 3 Point Arc Tool
Learn how to draw curved lines in 3Dsurvey using the 3 Point Arc Tool. This CAD feature lets you create smooth arcs by defining three points, making it useful for vectorizing curved objects and architectural details.
Getting Started with the 3 Point Arc Tool
The Arc Tool is located in the CAD tools, where the Circle Tool was previously found.
It uses three points to define a curve:
Start point: Defines where the arc begins.
End point: Defines where the arc ends.
Curvature point: Controls the shape and curvature of the arc between the two endpoints.
Select the starting point, the endpoint, and then a third point to define the curvature. For sidewalks with varying shapes, you can combine multiple arcs with straight polylines to follow the edges accurately.
Tips for Easier Drawing
Hide the Info Box
If the Info Box gets in the way while drawing, you can simply uncheck it to hide it. This gives you a clearer view of your work and makes vectorization easier.
Use the Quick Plane Lock
When working with elevated features, use the Quick Plane Lock by holding down the Q key while drawing.
The elevation will remain locked to the level of your first click for as long as you hold the key. This helps maintain consistent elevation and makes drawing on elevated surfaces more precise.
Example: Vectorizing Circular Roofs
The 3 Point Arc Tool is also useful for vectorizing architectural details, such as the round towers and conical spires of a medieval castle.
However, there is one important limitation: a single arc can span no more than a semicircle (180 degrees).
To trace a larger circular feature, divide the curve into multiple arcs. For example, when outlining a circular tower, switch to a top-down view to identify the center and position the curvature points accurately. Focus on the radius and center of the tower to align the arcs with the structure.
If an arc does not fit the entire shape, split the curve into two or more sections and use the Join Tool to connect the segments where needed.
Create More Complex Curved Features
The 3 Point Arc Tool can be used for a wide variety of shapes, from simple curved edges to more complex objects.
By combining arcs, straight polylines, and the Join Tool, you can trace features such as boat details, architectural elements, and other intricate curved structures. With careful point placement, even complex shapes can be recreated through vectorization.
Summary
The 3 Point Arc Tool is a straightforward and versatile CAD feature for drawing curved lines in 3Dsurvey.
Remember these key points:
Define each arc using a start point, an endpoint, and a curvature point.
Use the Quick Plane Lock (Q key) to maintain consistent elevation.
Keep in mind that a single arc is limited to a maximum of 180 degrees.
Combine multiple arcs, straight polylines, and the Join Tool to create more complex shapes.
With these techniques, you can efficiently vectorize curved features and achieve accurate results in your 3Dsurvey projects.
