Page 222 - Mastering SolidWorks

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uSinG Sketch PictureS 193

Creating a Derived Sketch
A derived sketch is a parametrically linked copy. The original parent and derived sketches do not
need to have any geometrical relation to one another, but when the parent sketch is changed, the
dependent derived copy is updated to stay in sync.
To create a derived sketch, you can select a plane or planar face, Ctrl+select the sketch you
want to copy, and then choose Insert ➢ Derived Sketch.
Once you create a derived sketch, you cannot change its shape or size; it works like a block of
a fixed shape driven by the parent. However, you can change the position and orientation of the
derived sketch. Figure 6.13 shows a derived sketch and its parent. Modify Sketch is a great tool to
use for manipulating derived sketches that are not related to things outside the sketch, especially
for mirroring or rotating.

Figure 6.13 original
a derived sketch and sketch
its parent

derived
sketch

Using Sketch Pictures
Sketch pictures are images that are placed in a sketch. You can resize and rotate the images, give
them a transparent background, trace over them, and suppress them. They display as children of
the sketch in the FeatureManager. You can use these image types as sketch pictures: BMP, GIF,
JPEG, TIFF, PNG, PSD, and WMF.
To bring a picture into a sketch, the sketch must first be active. Click Sketch Picture on the
Sketch toolbar (it is not there by default, so you may need to drag it onto the Sketch toolbar from
the Tools ➢ Customize ➢ Commands dialog box). You can also access this command by choosing
Tools ➢ Sketch Tools ➢ Sketch Picture from the menu. You cannot use sketch pictures in assembly
sketches, but you can use them in a part sketch in an assembly.
To change the size of a sketch picture, you can double-click it and drag one of the handles
around the outside of the image. Refer to Figure 6.14 for the Sketch Picture PropertyManager.
When the picture comes into the sketch, it is usually too big, having been sized at a ratio of 1
pixel to 1 mm. To size a picture accurately, you should include a ruler or an object of a known
size in the image. If you cannot do this, the next best thing is to guess the size. Draw a line in
your sketch and dimension it to approximately the size of something that is recognizable in the
image, and then move the image by clicking and dragging it to lay the dimensioned sketch entity
as close over the object in the image as possible.