Practical Autodesk AutoCAD 2021 and AutoCAD LT 2021
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Object Snap tracking

Object Snap tracking is a great tool for making geometries with reference to existing points in a drawing. To use this tool, activate it from the status bar, as in the following screenshot. It's the tool right next to the Object Snap icon:

F igure 3.27: The Object Snap tracking option in the status bar

Now, let's consider a scenario where we want to make a circle at point P, which is the intersection of the AB and ED lines if extended further along the dashed line, as shown:

F igure 3.28: A sample drawing for the Object Snap tracking option 

In this case, if we don't make the BP and PD lines, then we won't get the intersection point of these lines, which should be at the center of the circle. So, to get a reference like this, which does not actually exist in the drawing but exists only when existing drawings are extended further, we can use Object Snap tracking.

Now, to make the required circle on the P point, start the Circle command and then move your cursor to the B point but don't click. Now, move your cursor along the BP line so that a green tracking line shows up and when it does, move to the D point and once again, don't click and just track the DP line. You will once again get a green tracking line. Keep moving till you reach the P point and an intersection marker will show up, as shown:

F igure 3.29: The Object Snap tracking vectors are shown in green

Click to specify the center of the circle and then add its radius to make the required circle on the P point. In a similar way, you can use Object Snap tracking to track existing points of a drawing to get the references that don't exist in the drawing and make drawings using those references.

So, now we know all about creating precise drawings using Object Snaps and status bar options, it's time to dig deeper into the draw tools. In the next section, we will do just that with the ellipse tool, which happens to be a conic curve.