AutoCAD trả về cho bạn bản vẽ của bạn với các điểm nội bộ Chọn: nhắc nhở. 4. Chọn bất kỳ điểm nào bên trong khu vực đã đóng mà bạn muốn cho ranh giới của bạn. AutoCAD bắt đầu suy nghĩ như sau:Chọn tất cả mọi thứ . Lựa chọn tất cả mọi thứ có thể nhìn thấy . Phân tích dữ liệu đã chọn . Phân tích hòn đảo nội bộ . | 750 Part IV Drawing in Three Dimensions Using DVIEW To create a perspective view type dview J on the command line. At the Select objects or use DVIEWBLOCK prompt select the objects you want to include in the process of defining the perspective view. You should select as few objects as you need to visualize the final result if you have a complex drawing. If you want to select the entire drawing type all J even if the current view doesn t display the entire drawing. Press Enter if you don t want to choose any objects. AutoCAD substitutes a block called dviewblock which is a simple house. You can use the house to set your perspective view. Tip If you want you can create your own block and name it dviewblock. Create it with yv X Y and Z dimensions of 1. When you press Enter at the Select objects or z use DVIEWBLOCK prompt AutoCAD looks for dviewblock and uses it to dis- play the results of the perspective view settings. Understanding the DVIEW options DVIEW comes with a bewildering array of options that you use to specify the angle and distance of the view. To use these options start the DVIEW command and select the objects you want to view or press Enter. You see the following prompt Enter option CAmera TArget Distance POints PAn Zoom TWist CLip Hide Off Undo You use these options to define the perspective view as explained in the following sections. CAmera Use the Camera option to specify the angle of the camera which represents where you are standing. You need to specify the angle from the X axis in the XY plane and the angle from the XY plane. This is very similar to the way you specify a view using the DDVPOINT command explained earlier in this chapter. When you choose this option by right-clicking and choosing Camera you see the following prompt Specify camera location or enter angle from XY plane or Toggle angle in Chapter 22 Viewing 3D Drawings 751 The default angle is based on the current view when you start DVIEW. If you know the angle from the XY .