_______________________________________________________________________________________
jDraft Manual
___________________________________________________________
SPARETIMELABS
February 9, 2007
jDraft is a simple 2D drawing program for creating engineering drawings. On a superficial level it resembles simple drawing programs, such as old MacDraw or later day OpenOffice-Draw. But there is a difference. Anyone who tries to draw accurate drawings (that would conform to good engineering draftmanship guidelines) with these programs will soon find out that it simply is not possible.
The main design goal of jDraft was to make it possible to draw geometrically accurate/correct drawings in a simple and natural way, not unlike the time honored way of using a compass/divider and a straight edge. jDraft is by no means the only show in town, plenty of 2D CAD software around. Without badmouthing any particular software, I think it is fair to say that while those programs allow the creation of accurate drawings, many of them are not that easy to use. s jDraft attempts to be an animal of a different color, combining the ease of use of simple drawing programs with the accuracy of full blown CAD applications.
It is perfectly possible to use jDraft without any manual at all. The user interface conforms to the common idioms, concepts and practices of hundreds of other ’office’ applications. This manual is not about describing every button and check box in every dialog and window in the software. Instead, this manual tries to give insight into the design philosophy and advice at a higher level on how to use the software, addressing the deeper, underlying concepts that are not obvious from the user interface.
Unavoidably, this manual contains a bit (no pun intended) of computer jargon, some of which is specific to the operating system the application is being used on. It is not necessary to understand this jargon, it is included for the benefit of those who feel they need to / want to know it. You can safely ignore it. In most cases, using the software is totally intuitive if you are the least bit of computer savvy. In case you experience some ’computer’ woes you might want to lookup the jargon bits.
Mac OS users should substitute the COMMAND (aka Apple) -key for the CTRL -key.
In Mac OS, the CTRL -key is used together with a mouse click to effect the Right -click of other platforms.
Reading about a thing is all very well, but there is nothing like the real thing. So why not, take her for a spin!
Users of this application are most likely computer savvy enough to unpack it and just do it.
Just double-click on the application icon and you open up a brand new but empty drawing.
Select a line tool from the drawing tools palette and click or drag on the drawing area to create some shapes. Click on the snap tools to experiment how the cursor snaps to shapes you’ve already created, as you draw.
Go on, draw circles within circles (not a biblical reference here).
Pick the selection tool. Click and drag a shape to move it. Drag a box around the circles to select them. Click the fill icon to create a hatched area.
To contact SpareTimeLabs email to address
All feedback and suggestions are welcome.
See, it’s easy!
This manual expects that the user is accustomed to typical office applications, such as word processing and photo manipulation applications, and understands the desktop metaphora / file system. Some notion of engineering drawings is also highly desirable to appreciate what this is all about.
jDraft requires the Java Runtime Environment.
You can download the JRE from:
Sun website http://java.com.
jDraft is written in 100% Pure Java so it can run on a variety of operating systems. It has been tested on the following Operating Systems:
Note that these are not absolute requirements, the software has been tested on a 333 MHz Pentium 3 with 128MB RAM and it runs, but the speed is probably not acceptable. Obviously, the more of everything the merrier it gets. The recommendation is a 2 GHz Intel CPU with at least 1 GB of RAM. On Mac OS X platforms, the Intel Dual Core CPU based Macs offer significant performance boost over the Power PC CPU Based Macs. This is due to the lack of Just In Time compiler support. The Java 6.0 runtime also has a definite advantage in graphics intensive operations, as it includes most.
There is really next to nothing to install.
Just copy the application file to your hard disk and launch it by double-clicking it.
That’s basically all you need to know, if the above works for you, you can skip to the next chapter.
The application typically comes in a compressed archive as listed in table 2.2.
You can download the text archives from
http://sparetimelabs.com/jdraft.
Table 2.1: jDraft Distribution |
You can typically open and uncompress these archieves by simply double-clicking them. Uncompress and copy the application icon to wherever you want. Note that if you change the application file location after the file associations have been registered, you’ll need to unregister and then re-register the associations, see below.
On the first run the application offers to register itself as the handler of documents with the file extenstion / type ’.jdwg’, which is the native format for jDraft drawings. You can decline the file association registration and the software will work just fine, only you cannot open drawings by double-clicking them. You can register/unregister the file associations at any time from the ’File/Associations/ -menu. (Not available/necessary on Mac OS X).
Note: If you launch the application using Java Web Start, i.e. directly from the jDraft homepage, the file associations will not be available.
Whenever the application is launched it checks that a small number of files it needs for storing settings and such, exist. If they do not exist, jDraft will silently create them. It might make sense to back up these files from time to time.
For details, see Appendix A
To launch the application, just double-click the application icon or one of your drawings.
That’s basically all you need to know, if the above works for you, you can skip to the next chapter. The first time you use the application, you’ll need to click the application icon, not one of the drawing document icons, as the file associations are not yet registered. On the first launch, the application offers to do the regisration. Once registered, file associations let you open drawings by double-clicking them. As a detail, launching the application by double-clicking the application icon causes the application to open either the last edited drawing. If it is not available, like on the first run, it’ll creates a new, empty drawing. If you then go on and open more files from the ’File/Open...’ -menu without editing the first drawing, it will be automatically closed.
Note that in Linux the actual application file, ’jDraft-Linux’, which is a shell script and an executable jar file, will not have the jDraft logo icon. Instead, the desktop file ’jDraft.desktop’ has the ’correct’ icon. You can double-click either one to launch the application. The application is also available as an executable jar file:
'Draft.jar
|
which can also be launched on most operating system by double-clicking it. But it is also possible to launch the application explicitly from the command line with a command as follows:
java -Xmx1000m -Xss10m -jar 'jDraft.jar'
|
Quite a mouthful, but in case the double-click launch fails, you may need to try that. In fact, both the ’jDraft-Win.exe’ and ’jDraft-Linux’ files are ’.jar’ files masquerading as something prettier, so you can use it in above as well. The one advantage of launching from the command line is that you get the ’console’ output in the command line / terminal window. This is useful in case of troubleshooting as all the exceptions the application throws are printed there. Note that in Mac OS this is, cleverly enough, not necessary as the ’Console’ application is always available, even ’after the fact’, just go into the ’/Applications/Utilities/Console’.
jDraft is Shareware use of which is subject to a licence, see appendix B. You can try it until a fixed date after which some of the features are disabled, unless you register tha product. Registration is free. Currently the only feature that becomes disable after the trial period is Saving of drawing documents. Registration is via email.
To register your copy, send a request with your real name and your country of location to
and you will receive the registration key in a return email.
Copy/paste the registration key into the registration dialogue, which you can open from the ’Tools/Registration...’ menu.
The registration key is stored in the ’jDraft.config’ file alongside other application properties, settings and preferences. See Appendix A for details of the location of that file.
The application is pretty easy to use, so you may feel inclined to skip the rest of this manual, only using it as a reference.
That is just fine. However, before you get carried away and actually start producing your masterpieces, there are a few things you should consider.
The most important thing to understand is that almost everything related to the drawing is stored with each drawing. This is simple and conceptually clear. However, this means that there is no way to change something for every drawing in a single operation, sort of globally. As you work, you will notice that you always prefer to have some settings in a particular way, one that suits your style. In order to avoid adjusting the settings for each new drawing from scratch, you would be well advised to create a ’template’ drawing that contains the settings just as you like them.
Of course, the application comes with built in templates that conform to ISO standard engineering drawing formats for sizes from A4 to A0 and, of course, the application tries to provide reasonable default values for everything both in the templates and for files created with the ’File/New...’ command.
But there are bound to be settings that are not to your liking.
A simple way to manage this is just to create an empty drawing with your desired settings and then, each time you start a new drawing, open that template drawing and use the ’File/Save As...’ command to give it a different name. It’s important to remember to ’Save As’ it first, as otherwise you’ll be likely to modify your template!
However, a better alternative is to save your templates into a special ’templates’ directory (see Appendix A for details on how to find this directory). Anything that is stored there will be visible in the ’File/Templates’ menu. Selecting a drawing from that menu will create an ’Untitled’ copy of the template, forcing you to give it a proper name before saving it, thus preventing you from messing up your templates.
Maybe better yet is to take one of the ’built in’ standard templates and modify them. To do that just use the ’File/Open...’ command and find your way to the ’template’ directory.
Below is a list of things you might like to adjust to your liking. Note that, depending on your requirements, it might make sense to have a different set of templates depending on which sort of project you are working on. Drafting usually involves producing a set of drawings.
Note that the best time to create templates is probably after your first ’real’ drawing, because only by doing a real drawing will you get to know what your needs are.
Obviously, different sized drawings are needed for drawing parts of different sizes (and scales). Coordinate Systems A drawing can have any number of coordinate systems, each with their own origin and scale. The scale is the most important aspect of a coordinate system as the scale of the current coordinate system determines the units used in drawing with numeric values and in dimensioning. Typically, a drawing will have at least two coordinate systems, one that corresponds to the physical paper and is used for working with e.g. the title block, and another one that is determined by the part you are drawing.
A snap grid is used to force dimensions to a multiple of some basic unit, say 1 mm or 0.1 inch. Even if your style of drawing is based on geometrical construction, a grid is often a handy aid. Printer setup Perhaps not the first thing that comes to mind, but printing has a lot of options, and naturally you’ll want to print as soon as the drawing is ready and often before that. It is rather annoying if the printout then comes out partially clipped or in wrong scale. Equally annoying and wasteful is setting print parameters for each new drawing, especially as within an office the printing conditions tend to stay the same.
Line style defines the width, color and dashing of a line. For additional consideration on colors see below for ’use of colors’. Line styles a large de-facto defined by drafting standards. However, you may have your own preferences and variations. Worth noting is that any shape you draw refers to, but does not contain, a line style, thus changing the line style will change the line style of all shapes drawn with that line style within the document, but not across documents.
All shapes or drawing primitives, lines, circle etc., in a drawing reside on a layer. Layers define common attributes or properties for those shapes. For example you can turn a layer ’off’ to temporarily hide shapes on that layer. There are various layering schemes, such as keeping sketching and dimensioning on their own layers. In architectural drawings it might makes sense to have separate layers for structural, electrical, air condition etc etc.
Unlike in artistic drawings or illustrations, it is typical in a CAD drawing to use colors to distinguish between shapes on different layers. Therefore, even though a line style contains a definition for color, it can be overridden, but the color is defined for each layer. Indeed, that is the norm. Further consider that the physical paper is white, whereas many people prefer to work on a black background on the screen. A common and handy way to use colors is to have all colors defined as you want them to appear on paper. To do that, set the colors for line styles as desired. Often this reduces to using black for every line style. Then, to use colors to distinguish between layers on screen, use layer colors to override the line style colors. To get a black background on screen, do not set the background to black but use the ’Invert Colors’ option in the Preferences -dialogue instead. As you will be working with inverted colors, it is best to set and define the layer color scheme after you have turned on the inverted colors option.
The File menu (figure 4.1) contains the commands to manage your documents.
|
|
Documents can be opened by double-clicking their icons on the desktop, by using the ’File/Open...’ command or by selecting from the ’File/Recent Files’ -menu (figure 4.2) which remembers the last files/drawings opened.
|
|
It is also possible to open a drawing programmatically by giving the parameter on the command line.
-open filename
|
New documents can be created by selecting the ’File/New’ command or by selecting a template from the ’File/Templates’ -menu, figure 4.3. The template menu displays a list of predefined drawings that contain presets and pre-drawn elements for such standard items as title blocks, frame and aligment marks etc.
|
|
If you do not create a drawing from a template the next thing you propably want to do is to set the drawing size with the Settings/Document Size... -dialog, figure 4.4.
|
|
The Window -menu (figure 4.5) has commands to to Maximize / Maximize All windows (you’ll really want to use full screen for drawing) and shuffle through open windows in sequence. In addition to this, it lists all the open windows/drawing, allowing easy access to all open drawings. This is the preferred way to move between drawings.
|
|
The menu lists the open drawings in the order they have been opened, and this is also the order of cycling them. The current drawing, i.e. the one with the top most window, is marked with a check mark. An asterisk ’*’ in front of a file name indicates that the document contains unsaved changes.
obviously stores the document to its file, writing out any changes made. If the document has not been previously saved, it will prompt you for a file name and locaton. The command is only enabled if the document contains changes and this is thus an indication of whether or not you have touched the document contents in any way.
stores the document into a different file without touching the existing (if any) old disk file. It also changes the name of the open document so that any subsequent Saves go to the new file. You typically use this command to rename a document (however, if you need to get rid of the old file, you’ll have delete it manually).
saves a copy of the drawing as it is at the moment into a different file, without altering the name of the document. Any subsequent changes will go to the original file. You typically use this command to create a snap shot of a design for later reference, or maybe to have something to return to in case things turn nasty.
Figure 5.1 is a screen shot of a typical jDraft drawing as it appears on the screen.
|
|
The user interface consists of four main areas.
On top of each window there are controls that are common to most commands, such as setting the current line style and layer and whether snapping is confined to the current layer or active group.
On the left side there are, counting from top, Edit, Lines, Guide, Draw, Dimension and Snap tools for drawing and editing. All these toolbars and the layers toolbar on the top right can be detached from the window and dragged anywhere on the screen as illustrated in figure 5.2.
|
|
At the bottom of the screen there are entry fields for numerically entering values whenever necessary.
The biggest part of the window is taken up by the drawing area in the center. The drawing area has scrollbars to scroll different parts of the document into view, and a number view controls to left of the horizontal scrollbar.
Note that some toolbar buttons display a small triangle and/or a triple dot on the bottom edge of the button, see figure 5.3.
The small triangle is an indication that there is actually a palette or popup menu attached to this button. By clicking the button with the mouse and holding the mouse button down, you can bring up the popup menu which typically contains more variations of the command that the button represents. By selecting one of the alternatives the button changes to that command.
The triple dot is an indication that there is a parameters dialogue attached to the button for entering parameters. This dialogue screen typically allows you to enter and change a number of parameters that affect all the commands under that button. To bring up the dialog, double-click on the button.
|
|
Figure 5.4 illustrates where to find the most important drawing tools parameters dialogs.
|
|
The right-click menu also contains commands that are relevant to the currently selected shapes.
|
|
An interactive help facility can be invoked with the Tools/eGuide...command in the ’Help’ menu, see figure 5.6.
eGuide tracks you as you draw and gives hints on what to do next. As at any given time there are a number of actions you can take, the eGuide cannot give you step by step instructions. The hints are given in a computer generated, ungrammatical English, with apologies to any language puritans.
To exactly describe how the eGuide works is difficult, but broadly speaking the eGuide works as follows. Based on the selected drawing tool, the various ways of how you can draw are described in the eGuide window. The underlined items indicate what input you have entered so far. Below them is text describing how you can enter more input.
No textual description can do justice to the interactive quality of the eGuide so it is suggested that you just try it. On the other hand, it is likely that you do not need guidance at all!
|
|
Moving around in the document. - such a deceptively simple, but essential subject that deserves a chapter of its own. At any given time, the drawing area shows some part of the drawing. If it were not so confusing, you could say it is a window to the drawing. Technically, it is called a ’pane’ as in a window pane. By moving this pane and/or the document visible through the pane is how you bring various parts of the document into view, and therefore it is also customary to call it a ’view’.
As drawing and designing are mostly visual tasks, it is essential to be able move around in the drawing to see what you are doing. That is why jDraft provides so many ways to do that and why it is essential to master at least some of them. You don’t need to use them all, but it’s essential that what you do use becomes a second nature so that moving around does not distract you from drawing.
Most of the View controls relate to a specific view (see below on multiple views in section 6.8.2) so the view controls are attached to the lower left corner of each view, see figure 6.1.
|
|
You popup the View -menu by clicking on the small arrow.
One of the most useful view controls is the Mouse Wheel, especially in laptops that have a touch pad and support two-finger drag gestures, like in Mac OS X. Rolling the wheel causes the view to be centered at the current mouse location and be zoomed in/out with small amount for each wheel increment. This makes it very easy and fast to both move around and zoom in/out. Just move to cursor to the location in your drawing that you are interested and roll the wheel (or gesture with two fingers). Small scrolls/gestures effectively just move your point of interest to the center of the screen while larger scroll wheel movements enables you to zoom in/out.
The good old scrollbars on the right and bottom of the pane move the ’window’ over the document. You scroll by dragging the knob (a.k.a thumb) around. You can also scroll by small increments by clicking at the small arrows. By clicking the ’track’ on which the knobs slides, you can scroll half screen fulls at a time. The size of the knob relative to the size of the track gives an indication on how much of the document is visible at the moment. Think like pane size = knob size and track size = document size.
Should be familiar concept from myriads of other appications.
Because there are so many ways to move around, sometimes a single mouse gesture moves your view to somewhere totally wrong, from which it can take a lot of navigation to find your way back. This can be really frustrating and may interrupt your thought/drafting process. For this reason jDraft remembers the last ten view positions for each pane so you can move back and forth between these view position with these buttons.
This button resizes and repositions the pane (or document, depending on your view point, pun intended) so that the whole drawing is visible. This is handy if you get totally lost - it is a sort of ’reset’ button.
These buttons make the document (or pane depending on your view point, pun intended) larger or smaller. The icon with the plus sign makes the document larger, as if you are moving the document closer to you. This is known as Zoom In. The other one is, of course, called Zoom Out and makes the document appear smaller, showing more of it.
This button activates the Zoom Command. Clicking this button once activates the command into a so called one-shot mode in which, after zooming once, the current drawing command is resumed. This makes it handy to quickly zoom in (or out for that matter) while drawing something, without interrupting your drawing command. Double clicking activates the Zoom Command so that it remains in effect until another command is selected or the Zoom Command button is clicked once more. You can also activate/deactivate this command by pressing the ’Z’ key (without any modifier keys). Pressing ’Z’ toggles between the Zoom Command and your current drawing command. When the Zoom Command is active the cursor takes one of the following shapes:
The Zoom In (plus sign) is the default and is active unless you press the ALT-key on the keyboard, in which case the Zoom Out (minus sign) mode is in effect as long as the alt key is held down. Clicking with the mouse zooms in/out by a factor of 1.41 effectively doubling or halving the visible area of the document and centering the view at the click location.
If you click and drag with the zoom command to specify a rectangle the view is resized and repositioned so that the area of the rectangle fills the view. Note that you can activate this same Zoom Command click and/or drag feature at any time with center mouse button.
If the SHIFT-key is held down, the cursors turns into a hand shape. In this mode you can grab and move the document by dragging it with the mouse. You can also at any time center the view at the mouse location without pressing any of the mouse keys - just press the key ’Q’.
This menu contains lots of less frequently used view control commands, most important of which is rotating the view. More on this later in Advanced view options.
A feature often not seen in simpler drawing programs is the ability to rotate the document in relation to the view. In engineering drawing this is not a very often required feature but in architectual applications the need sometimes arises, as two wings of a building may be at odd angles to each other, making working on at least one of the wings less than optimal, as illustrated in figure ??
|
|
Working with features that are not aligned with the document side becomes easy if you rotate the view to align it with the feature being drawn an create a coordinate system to match,
Rotation can be specified numerically with the view menu command ’Set View...’ More often, though, the actual view angle may not be known precisely - instead it is the result of geometric construction or some such. In these case the easiest way to align the view is to select a line that you want to be horizontal or vertical in the view and use the ’Align With Selection’ command followed with ’Rotate 90’ / ’Rotate 180’ commands from the view menu, until the desired orientation is achieved.
It is also possible to align the view with the current User Coordinate System (UCS).
Very often in large drawings it becomes necessary to draw lines or other features from one end to the other. To snap accurately you need to zoom in on both ends in turn, which can be a burden if many such lines are required. For this purpose any view can be split into two views, either horizontally or vertically, as illustrated in figure ?? Now both views can be independently zoomed in on different locations on the document, and drawing can be carried out by clicking on the view that provides the best visibility.
|
|
A drawing consists of the following types of shapes or drawing primitives, see also figure 7.1:
|
|
In additions to these ’printable’ shapes there are also
which are visible on the screen but do not appear in the printout.
Except for Text Blocks and Filled Areas, for obvious reasons, each shape has a Line Style associated with it, which determines the width, color and dashing of the line that renders the shape.
Line Styles are shared between all shapes within a drawing so that changing/editing the line style affects the appearance of all shapes drawn with that Line Style. This is powerful and practical but is different from e.g. typical painting applications, where a line is drawn with one color and to change the color it is necessary to redraw with a different color.
Line Types are stored with the document and there is no explicit way to transfer line types from one drawing to another. However, if you copy/paste a shape from one document to another the Line Style is copied as well, of course. This does not create a link between the documents, so changing the Line Style in one does not change the other. Line Styles can be edited in the ’Settings/Line Styles...’ -dialog.
All shapes reside on a layer. Layers are the main tool for keeping your drawings manageable. As drawings get more complicated, especially with assembly or general arrangement drawings showing multiple overlapping parts, they soon become incomprehensible and impossible to manage without the use of layers.
There are a number of layering schemes, and you need to come up with one that works for you. Most people seem to use layers to differentiate between parts. This often makes sense as it allows you to turn off (hide) parts selectively. Different engineering disciblins have different needs.
A layer is like a transparent drawing sheet. The drawing document is made of a stack of such sheets. The layers have a back to front order which determines which shapes take precedence when shapes overlap.
The current Layer is displayed and can be changed with the Select Layer combo box on the top toolbar. The Layer combo box can also be dragged out of the toolbar and used as a floating toolbar, giving instant access up to 30 layers and their properties with a single click.
Layers have the following properties
No two layers can have the same name. Names are case sensitive. If a layer is not visible (is hidden) then none of the shapes that are on that layer are visible and cannot be picked, snapped to or in any way manipulated. It the layer is locked, the shapes on that layer cannot be manipulated or selected, but you can snap to them.
If the layer is snappable, you can snap to objects on that layer, otherwise they are ignored.
If the use color-attribute is set, shapes on that layer are displayed using the layer color, not the color dictated by the shape’s Line Style.
Shapes can also be grouped together. A group behaves like a single entity. If you select one of the shapes in the group, the whole group becomes selected. If you move one shape, the whole group moves and so on. Groups are not in any layer, but rather the shapes that make up a group are each in their own layer.
A group can also contain groups, so it is possible to have hierarchical structures that may help in managing drawing in certain situations. To form a group, you select the objects to you want to include in the group and click the Group button.
If the group contains reference points they become snap points and handle locations for the group, which is a very powerful way of creating ready to use parts that can be easily snapped into the right positions.
(If there are no reference points, an artificial reference point is calculated as the mathematical center of the bounding box in the paper coordinate system for all shapes in the group.)
It is possible to work inside or within a group, modifying the group without first ungrouping it. To do that, select a group and click the Work In Group button or simply double-click the group. When you are working inside a group all shapes that are not a part of the group are displayed as gray. When working within a group, all shapes you draw will be added to the group.
Text blocks are like mini word processing documents, in which you can use different fonts, sizes and styles (bold,italics). In order to be able to create precise layouts, the text blocks are layed out relative to a so called anchor point. The anchor point can be defined to be at key location relative to the text, for example in the beginning of the baseline of the first text line etc.
Filled Areas are created by selecting one or more shapes. The outlines of those shapes are combined together to form the boundary of the Filled Area, and the inside of that area is filled with the current Fill Pattern. The insides are determined using so called odd/even ruler, which works by drawing an imaginary line from a point to infinity and counting how many times the line crosses the boundary of the shape. An odd count indicates that the point is inside. Each Filled Area has four handles which also serve as snap points. These handles are at the corners of the bounding box of the boundary in the internal document coordinate system. As the bounding box is not precise, you do not want to snap to these handles.
Filled areas cannot be stretched.
Filled areas are always on a layer, but within in that layer they are behind all other drawing shapes except guide lines.
Fill Patterns are used to fill the area covered by selected shapes by pressing the Fill button.
Unlike Line Styles, the Fill Patterns are not shared between shapes and the Fill Patterns you see in the Select Pattern -combo box are not stored with the document, but in the file ’jDraft.patterns’. For the location of that file see Appendix A.
When a filled area is created the corresponding pattern is copied from the pattern file to the drawing.
Each fill pattern has a name and no two fill patterns can have the same name. Names are case sensitive.
The current fill pattern grid is displayed and can be changed with the Select Fill Pattern combo box on the top toolbar.
Fill Patterns come in three different types:
To edit the Fill Patterns bring up the Fill Patterns -dialogue, figure 7.2 with the Settings/Fill Patterns... -menu command.
|
|
Hatches are the traditional method of indicating cut away sections or surfaces on technical drawing. They are defined by:
You edit Hatch patterns by bringing up the Hath Pattern -dialogue, figure 7.3 selecting the pattern and clicking on the Edit -button on the Fill Patterns dialogue.
|
|
Typically, only the spacing and angle of the hatches are varied as the Line Style is dictated by drafting standards (usually a thin solid line). Sometimes, for example if an equally spaced hatch consisting of parallel lines needs to be created, it is necessary to use a different Origin for the two hatch styles, otherwise the lines will simply overlay each other.
If cross-hatching or hatching with alternating line styles is needed it is necessary to hatch multiple times with different patterns.
Figure 7.4 shows some typical hatch pattern combinations used in engineering.
|
|
When multiple filled areas with the same fill pattern overlap, the patterns ’blend’ together, which is desirable as, if e.g. the hatching of an area needs to be done in parts it is important the hatches appear continuous.
You edit Solid patterns by bringing up the Hath Pattern -dialogue, figure 7.5 selecting the pattern and clicking on the Edit -button in the Fill Patterns dialogue.
|
|
Solid fills are simply areas filled with a single, solid RGB color.
Raster Patterns are based on tiling a picture side by side to cover the Filled Area.
You edit Solid patterns by bringing up the Hath Pattern -dialogue, figure 7.6 electing the pattern and clicking on the Edit -button in the Fill Patterns dialogue.
|
|
Raster Patterns are created from image files (TIFF,GIF,JPEG and PNG formats are supported).
Raster Patterns are very powerful and can be used to created any kind of fill effects. However, the resulting output quality is defined by the resolution of the image used to create the pattern.
There is a tradeof between the accuracy (resolution) and file size. Obviously to create the perfect, for example ’concrete’, pattern one would draw by hand a A4 sized sample, scan it at 300 DPI resolution and import it into fill pattern. Unfortunately, this would create a pattern of size 210x297x(300/25.4)2x4 bytes, a whopping 34 MBytes!
So the recommendation is to use patterns about 100 x 100 pixels at 72 DPI or thereabouts. This creates patterns of about 40kB in size and produces an acceptable output on a typical office printer.
Drawing aids is, in a way, what jDraft and 2D CAD is all about, to be able to draw accurately and with ease.
Accurately here means with precision.
When you draw shapes, lines, arcs, anything, you are not limited to the accuracy of how well you can point with the mouse or see what you are drawing on the screen. Instead when you draw e.g. a line from point to point, you pick the point on something that is already defined in the drawing, say the end point of another line, the crossing of two lines or from a grid. Or you define it by constraints, saying that the line is to be a tangent to a circle and passing through a point. Precisely, perfectly.
In the end, the drawing is probably printed on a paper with a printer having a resolution of about 300 DPI (5 lp/mm) so why this craving for accuracy?
To understand this, consider that in a drawing made at 1 : 100 scale the above mentioned printer resolution results in an accuracy of about 0.1 mm which would mean that any Dimensioning would have a precision of about 10 mm! Clearly not acceptable. And things would get even worse as things are copied and pasted as the accuracy would deteriorate every time.
Hence the need to draw precisely.
Of course, nothing is perfect and for the technically inclined the accuracy is limited by IEEE double precision floating point math and is aproximately sixteen significant digits. Note that some geometrically almost singular cases can affect the accuracy of the math jDraft performs, such as intersection of tangential lines and circles or almost parallel lines. Also, the mathematics related to splines and ellipsoids are not always as precise because they rely on numerical rather than analytical models and thus things like intersections of splines and ellipsoids may not be as accurate as intersections of, say, lines and circles.
Whenever you are drawing, the cursor turns into a cross hair. In addition to this cross hair that moves as you move the mouse, there is a Snap Cursor, figure 8.1 that tracks the point that would/will be entered if you click with the mouse. This snap cursor gives clear visual indication of what the cross hair cursor is snapping to.
|
|
Sometimes seeing the snap cursor is not enough. Consider a situation where two lines start from almost, but not quite, the same point. In order to draw precisely it is important to see which one is snapping the cursor. To help visualize this, the shape(s) snapped to are Hilited with a hilite color (orange by default, but you can change it in the preferences dialogue).
The above introduction covers the fundamentals of snapping to shapes.
In short, all you have to do is to select the snap mode and point and click at the shape you want to snap to. The snap cursor and the hilite indicate to you what you are doing. Figure 8.2 shows most of the shapes with their Handles which are also their snap-points. Note that sometimes the snap cursor and what you are pointing to with the cross hair cursor can be wide apart on the screen, for example when you are snapping to a center of a circle you point the circle circumference with the cross hair but the snap cursor will appear at the center of the circle.
|
|
Often there are two or more points into which the cursor could snap to, like two end points of a line. In situations like that, the software selects the closest one and thus you can affect what the software picks (in case it is not what you want) by moving the cursor to a different point.
You select the snap mode in effect using the Snap -toolbar in figure 8.3.
|
|
Snapping can be restricted to shapes on the current layer (as opposed to all visible layers) and to all visible shapes, shapes that are lower in the groups hierarchy (in other words shapes that are sub-groups of current group) or only to the current group. You control this with the Snap Controls -toolbar in figure 8.4.
|
|
A Grid is a rectangular array of points that are spaced at equal distance from each other. When you snap to a Grid the nearest grid point is picked. This makes it easy to draw things to conform to some, well, grid. Any number of grids can be defined, but only one of them can be active at any time. Grids have names and colors to distinguish them on the screen and lists.
The Active grid is displayed, and can be changed with, the Select Grid -drop down menu on the top toolbar.
Figure 8.5 shows the grid setup dialogue which you can bring up from the Settings/Grids... -menu command.
|
|
Each grid has the following properties
Spacing determines the distance between grid points.
Color is the color used to display the grid on the screen. When a grid is active, it is displayed as a rectanglular array of tiny dots behing all layers.
Ticks specify how dense the displayed grid/dot array is. A value of one causes each grid point to be displayed, a value of five shows every fifth grid point only. Note that in order not to fill the screen with dots when the grid is dense or when the view is zoomed out, the sofware selectively displays even fewer points than specified by the Tick property.
Snapping however always takes place at the Spacing resolution, regardless of the display grid points.
Guide lines come in two varieties, lines and circles. You create guide lines with the tools in the Guide -toolbar, see figure 8.6 and figure 8.7.
|
|
|
|
They behave mostly as normal lines and circles, you can move them, copy them etc. They are on a layer, obey the layer visibility and color and so on. But most importantly, you can snap to them. That is what they are for.
They differ from ordinary lines and circles in three respects.
The Guide Lines Style has by default width of zero which makes a guide line always to appear as one pixel wide regardless of the zooming. You can edit the Guide Line Style as any regular line style by bringing up the Line Style -dialogue with the ’Settings/Line Styles... -menu command.
Reference Points are small markers that you can make. Like guide lines, they are not printable. Reference Points have no size, so they appear the same regardless of zooming. This is mostly handy but can be annoying when zooming ’all out’.
|
|
A large number of reference points is usually a pain when drawing.Therefore Reference Points come in two varieties, permanent and temporary. Permanent Reference Points are like any other shapes, they exist until you explicitly delete them.
Temporary reference points, on the other hand, are consumed as you draw snapping in to them. After all, once you draw a line snapping to a Reference Point, the Reference Point is superfluous because now you can snap to the end of that line when necessary.
By default all reference points are borne temporary. Guide Lines and Reference Points both reside on some layer. By default they are created on the current layer. However, you can specify that they are created on a specific layer regardless of the current layer.
To change these settings, double-click on the Reference Point button in the Guide palette to bring up the Guide Parameters -dialogue, see figure 8.9.
|
|
You create Reference Points with the tools in the Guide -toolbar, see figure 8.10.
|
|
All shapes have snap points to which you can snap. Most of them are intuitively placed and obvious, like end points and center points. Mostly these are in the same locations where the Handles appear on selected objects. However, there are some exceptions that you may want to know of.
Circles have four handles that are at 90 degrees apart on the circumference. These handles are wherever you drag them. In addition, these circles have four ’quarter points’ that are also 90 degrees apart but are aligned with the current coordinate system, as illustrated in figure 8.11. You can snap to all of these.
|
|
Line ends and vertexes for polylines are snap and handle locations. Line centers and line segment centers for polylines are snap points, in snap to center mode, although there are no handles there.
Every text block has an anchor point. The text layout is defined relative to this anchor point, which also serves as both the handle and the snap-to location
Sometimes, especially when you are snapping to the crossing of two shapes, there are more than two shapes so that it is impossible to point with the cursor so that exactly the two shapes that you want are picked. You can see from the Hilite that the wrong two shapes are being picked, but no matter how you move the cursor or zoom the display you just can’t pick the right ones. This is surprisingly common with horizontal/vertical lines drawn on top of each other. The
Figure 4.1: The File -menu
Figure 4.2: Recent Files -menu
Figure 4.3: The Template -menu
Figure 4.4: Document Size -dialog
Figure 4.5: The Window -menu
Figure 5.1: A jDraft Window
Figure 5.2: jDraft Toolbars
Figure 5.3: Pallets and Parameters
Figure 5.4: Finding the Parameters Dialogs
Figure 5.5: The Right Click -menu
Figure 5.6: Hatching Combinations
Figure 6.1: View Controls
Figure 6.2: Rotated Views
Figure 6.3: Multiple Views
Figure 7.1: Drawing Primitives
Figure 7.2: Fill Patterns -dialog
Figure 7.3: Hatch Pattern Edit -dialog
Figure 7.4: Hatching Combinations
Figure 7.5: Solid Pattern Edit -dialog
Figure 7.6: Raster Pattern Edit -dialog
Figure 8.1: Snap -cursor
Figure 8.2: Shapes and Snap Point/Handles
Figure 8.3: Snap Tools -toolbar
Figure 8.4: Snap Controls -toolbar
Figure 8.5: Grid Parameters -dialog
Figure 8.6: Line Guides -palette
Figure 8.7: Circular Guides -palette
Figure 8.8: Reference Point
Figure 8.9: Circular Guides -palette
Figure 8.10: Reference Points -palette
Figure 8.11: Circle Handles and Quarter Snap Points