Editing Objects with AutoCAD - Section 4

18.3 Matrix

The Matrix command creates multiple copies of an object and arranges them according to three criteria: as a rectangular matrix, as a polar matrix and as a path matrix.
The rectangular matrix and its characteristics can be established dynamically with the mouse, with the ribbon or through the command window. The object to be duplicated is chosen and Autocad responds with a pre-established array of the matrix, which contains small blue-colored signage called grips (to which we will dedicate a particular chapter) with which we can modify it using the mouse. We can also capture their values ​​in the contextual tab of the ribbon that appears or we can capture them in the command line window. With any method, what is involved is to establish the number of rows and columns of the matrix and the different distances between its elements.

As was clear in the video, the parameters to establish to construct a rectangular matrix, basically are:

- The number of rows and columns of which the matrix is ​​composed.
- The horizontal and vertical distances between its elements.
- The base point that serves as a reference to measure these distances.
- Whether the matrix is ​​Associative or not. An associative matrix can be edited together. If we modify the source object, the elements of the matrix change. If the associative property is No, then each element of the matrix will be an object independent of the rest.
For its part, the polar matrix creates the number of duplicates indicated, but around a center. We can also define the number of elements of the polar matrix, of course, as well as the angle to be covered by these elements and the distance between them. And as in the previous case, we have a series of options to modify and establish the characteristics of the matrix:

- Associative. This option is simply set to Yes or No. An associative matrix can be edited together. If we modify the source object, the elements of the matrix change. If the associative property is No, then each element of the matrix will be an object independent of the rest.
- Base point. Allows you to modify the point of the matrix from which your grips are presented.
- Elements. It allows to modify the number of elements of which the matrix is ​​composed.
- Angle between. Specify the angular distance between the elements of the matrix.
- Fill angle. Specify the total angular distance that the matrix elements will cover
- Rows Define more than one row of the matrix. The second row, and subsequent if desired, will have the same number of elements as the first matrix, but will be concentric to it at the distance we specify when using this option.
- Levels Specify the number of levels of the matrix. This option makes sense in the 3D drawing
- Turn objects. This option is specified only as Yes or No, which determines whether the objects will be shown rotated according to the angle at which they are located.

Obviously, there's nothing like watching this in a video.

The last type of matrix that we can elaborate is the one that allows to create diverse copies of one or more objects on a trajectory, which can be a line, a polyline, a spline, an ellipse, a circle, an arc, and even a propeller . With the options we can indicate the number of elements of the matrix and how they are to be distributed on the trajectory, not only in terms of distances, but also in relation to their alignment. Compared to the methods to build the other two types of matrices, we can say that there are few changes, but let's take a look at the following video.

18.3.1 Edit Matrix

In the immediately preceding section we create matrices through an edit command. Now, modifying these matrices requires a new command, also called editing, precisely Editmatrix, which has its advantages, since most likely, when modifying the source objects of an array, we want all the elements of the matrix are also modified. So even though it sounds peculiar, we should check this edit command that modifies objects created with an earlier edit command.
It can be said that the requirement to edit an array is that its associative property is activated, otherwise the objects in the array will be considered independent of each other and it will not be possible to apply the command. After specifying the matrix to be modified, the subsequent options depend on the type of matrix involved (rectangular, polar or path), although in each case it is not difficult to elucidate that what is involved is to modify its number, their distances (or angles in the case of polar matrices) or other common characteristics.
Another method, new in this version, is to select the matrix to be edited with what opens a contextual eyebrow in the ribbon called Matrix with which although we can not modify the objects of the matrix individually, we can alter their parameters (distances, number of elements, rows, etc.).
Therefore, let's review how to modify the elements of a matrix in three cases: 1) editing the elements that compose it, which will modify all other elements of the matrix; 2) modifying one or two elements in the particular without changing the rest and; 3) by opening the contextual ribbon eyebrow.

18.4 Splice

The Splice command joins the edges of two objects and rounds them with an arc. Its options allow us to define the value of the radius (which is specified for future executions of the same command), as well as allow us to indicate if it is a polyline, in which case the command will create a splicing arc in all segments in where two lines form a vertex.

18.5 Chamfer

This command bisects 2 edges at the specified distance or angle. The lines to choose for the chamfer should not be parallel, otherwise the command can not be executed, although they do not necessarily need to form a vertex, since the command, in addition to trimming, can lengthen the lines up to the bevel. The options of the command allow to indicate the distance of each line from where the bevel will appear; or, we can give a distance and an angle from the first line.
Finally, if we have a rectangle and want to bevel all its corners at the same distance (or distance and angle), then we should remember that rectangle is also a polyline. If we use this Chamfer command option, then chamfering can be done in one step.
The command includes the Multiple option, so that it can be applied to multiple objects without having to restart it.

18.6 Merge curves

Merge curves is a command that allows you to create splines between the end points of open curves, which can be arcs, elliptical arcs, splines, straight lines and open polylines. When activating the command we must select the two segments to join, but near their endpoints, as a function of this will create the spline.