Designers in the drawing of some simple three-dimensional graphics, usually need to mark the processing size, such as furniture, shelves and other simple three-dimensional graphics. See a lot of friends are not in the CAD to mark the size, but in the CAD to draw the figure after the print out, with a pen and then mark the size. Today we are in the CAD for a simple shelf three-dimensional graphics dimensioning, for friends as a reference.
There is no three-dimensional annotation function in AutoCAD, and Dimensioning is based on two-dimensional graphic plane. Therefore, in order to mark the three-dimensional graphics, we should find a way to convert the dimension to the plane, that is, to convert the three-dimensional annotation problem to the two-dimensional plane and simplify the annotation. This will be used in the user coordinate system, as long as the coordinate system to the need to mark the plane on it. Therefore, if you want to learn three-dimensional annotation, you must first familiarize yourself with the UCS transformation. The bottom of the author is a shelf of three-dimensional graphics for example, a brief description of three-dimensional graphics.
Figure 1 is a picture of the three-dimensional graphics of a shelf diagram, below which we mark the dimensions for this three-dimensional frame chart.
Figure 2 is the graphic that completes the dimension callout.
Fig. 1 Figure 2 Complete dimension marking after blanking
First, in the upper plane marking edge size
Move the XY plane of the UCS coordinate system to the upper plane of the shelf, first on the upper plane for its corresponding edge dimension.
The specific steps are as follows:
1. Type UCS carriage return at the command line, type M carriage return, and capture the top right point with the endpoint at the specified new origin or [z-depth (z)] <0,0,0>: Command prompt, as shown in Figure 3, the endpoint capture:
Figure 3 Endpoint capture Figure 4 axis move to Endpoint
2, then need to rotate around the z-axis coordinate system -90°, type UCS carriage return at the command line, type N carriage return, type Z return, enter-90 return to the car, complete the transformation of coordinate system. Then it can be in the upper plane dimension, so that the three-dimensional side of the callout to the two-dimensional plane, the annotation method and the two-dimensional annotation is identical, the size of the callout chart as shown in Figure 5;
Figure 5 No rotation callout Figure 6 Rotate Callout
Note: If you do not rotate the coordinate system in step 2, the callout graph is not in line with the custom of the callout, as shown in Figure 6.
Second, the height of the label shelf size
Convert the XY plane of the coordinate system to the plane on the right side of the shelf, type UCS carriage return at the command line, type Y enter, type 90 back, so that the XY plane of the coordinate system is positioned on the plane on the right side of the shelf, and, similarly, the side of the dimension to be marked is converted to the plane, and the dimension as shown in Figure 7.
Figure 7 Marking Shelf Height
Third, for the bottom dimension
In the same vein, move the XY plane of the UCS coordinate system to the bottom surface and then label the dimensions as shown in Figure 8.
Fig. 8 Dimensioning of the bottom surface
The final finished frame of the three-dimensional dimensioning diagram, as shown in the figure.
Final completion diagram