Dynamic Rotation
Dynamic Rotation
| Dynamic rotation uses |
<left mouse> + <left shift>
&/or <left control> |
(The distinction between the keyboard meta-keys is explained in Graphics modes during dynamic viewing above.)
Rotation always take place in the screen coordinate system, and may be about the XY axes or Z: this depends upon the starting position of the mouse. This is shown in the next figure:
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If the mouse initial position is inside the central circle ( radius (screen height/3) ) then rotation is about screen XY axes. If the initial position is outside this circle then rotation will be about screen Z. You can tell which mode you are in by the cursor symbol. This is red , and:
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The relationship between mouse and image motion is intuitive
in both modes. It is as if you had grabbed a point on the object near you,
(this side of the object centre plane), and used this to move the image
about its centre:
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| XY mode |
Moving the mouse left/right rotates about the screen Y axis;
Moving the mouse up/down rotates about the screen X axis. |
| Z mode |
Moving the mouse in a circular direction rotates about the screen Z axis. |
| Rotation remains locked in its initial XY or Z mode for the duration of a dynamic viewing operation, regardless of where you subsequently move the cursor to, until you release a mouse or keyboard button. | |