LT Unlimited

Exploring the Units Dialog

You can use the Units dialog choose the display and input format of length and angle measurements. The command location has moved around a bit in recent years: In LT 2010, it's under the Application Menu-->Drawing Utilities-->Units; in LT 2009, it's on the Tools tab, Drawing Utilities panel; in previous versions look under Format-->Units; and in all versions you can type UNITS.

For length, you have the following options. The numbers in parentheses show how a sample length -- 41.5 units -- would be displayed with each type.

• Architectural (3'-5 1/2")
• Decimal (41.5)
• Engineering (3'-5.5")
• Fractional (41 1/2)
• Scientific (4.15E+01)

You can choose the precision you want to display, from low to high -- this doesn't affect input, just how many decimal places or fraction denominators you'll see when you list something or use a measuring command.

You can also choose the format of your angles. The numbers in parentheses show a sample angle -- 30.5 -- would be displayed for each type.

• Decimal Degrees (30.5)
• Degrees/Minutes/Seconds (30d30'0")
• Grads (33.889g)
• Radians (0.5323r)
• Surveyor's Units (N 59d30'0" E)

You can set the display precision for angles too, and choose to have them go clockwise instead of counterclockwise.

For any of these linear or angular formats, you can only use special characters that correspond to the current type. For instance, entering 4'6 when your type is set to Decimal or 45d10 when your type is set to Grads won't work. But decimal entry always works.

The Insertion Scale option has to do with copying content between files that have different units. It's related to other settings in the Options dialog, so I think I'll say more on that another day.

Finally, down at the bottom, is the Direction Control dialog.

This enables you to set the "zero" angle for your file -- to the right (East), up (North), left (West), down (South), or any direction you choose. (East is the default -- it corresponds to most standard coordinate systems.)

Wipeout!

So I promised you in my last post that I wouldn't get carried away talking about all the fun new stuff in AutoCAD LT 2010, and I'm sticking to that. In fact, today's topic has been around since at least AutoCAD LT 2006. (That's the oldest version I have access to right now. If someone with an earlier version has other information on when it showed up, please let me know.)

Wipeouts do just what you would think -- "wipe out" part of your drawing -- although it's not quite as devastating (or permanent) as it sounds.

A wipeout is simply an object that can cover other objects with a blank area, either to make text more legible or to cover up unwanted portions of a drawing. It doesn't erase anything, just covers it up. You can control exactly what is covered with the Draw Order command.

For example, let's say I needed to cover up part of this line of shrubs/bushes.

I'll start the Wipeout command (either from the ribbon, the Draw menu, or the command line) and choose enough points to define the shape I need. A wipeout is always closed -- the command always draws the last side of the polyline for you. I could also use the Polyline option of the command to choose an existing closed polyline to convert to a wipeout.

The wipeout is automatically created so that it covers up all my existing objects.

If I don't want that, I can use the Draw Order command to bring some of the objects on top of the wipeout.

Finally, if I don't want the frame of the wipeout to print, I can use the Frames option of the wipeout command to turn them all off. This option has two limitiations: You can't select a wipeout if its frame is off, and you can't turn off specific frames individually. It's all or nothing.

Drafting Settings Part 5 -- Quick Properties

All right, we've reached the last tab in the Drafting Settings dialog! Welcome to Quick Properties.

In case you haven't seen Quick Properties palette yet, it's a miniaturized version of the full Properties palette that pops up when you select an object in your drawing. It looks something like this:

Of course, you can customize this palette to best suit the way you work. If you couldn't change some settings, we wouldn't be talking about it, would we? So here are the Quick Properties settings:

Like every other tab we've seen, this one has an on/off checkbox right at the top. Right below it, though, is an interesting setting specifying precisely when it comes on. You can choose to have Quick Properties displayed for every object, or only for "defined" objects. A "defined" object is one that has some of its object-specific properties chosen for use as quick properties. Object types that are not "defined" would show only color, layer, and linetype.

Where you do you define these objects? Take a look back at the shot of the Quick Properties palette, and look for the icon in the upper-right corner, next to the object type name. That's the Customize button, and it takes you directly to the part of the CUI editor where you can select which objects have Quick Properties at all, and what those properties are. It looks like this:

 

So here, a selected circle will display its radius and area, but not its diameter, in the Quick Properties palette. To add one more level of customization to this, you can choose which object types appear in the left-hand list using the button at the top of the image above. You can probably identify which properties are most important to you in a short swing through this dialog.

Under "Location Modes", you can choose where on your screen you want the palette to appear. "Float" means that it will appear in the same place every time, just like a regular palette. "Cursor" means that it will pop up next to your crosshairs, whereever they are on the screen. If you choose Cursor, you can also further specify the position by quadrant (top-right, top-left, bottom-right, bottom-left) and by the distance (in pixels) that the palette will stay away from the cursor.

Finally, you can control the size of the palette with the Auto-Collapse option. If you turn on Auto-Collapse, you only see a few rows of the palette -- you can choose how many -- until you hover your cursor over it. If Auto-Collapse is off, you see all available quick properties immediately. If you are more likely to use Quick Properties to view object information, you might find Auto-Collapse helpful, but if you are more likely to use it to make changes to object properties, you may find that Auto-Collapse is more cumbersome (because you have to wait for it to unroll before you can make your changes). In the end, it's up to you.

Well, I think that's the end of what I have to say about the Drafting Settings dialog. Thanks for hanging in for the full tour. I hope you learned a few new things (I did!), and that you'll be able to use a few of them to be more productive.

Drafting Settings Part 4B -- Dynamic Input, Cont.

Last time on LT Unlimited, I continued the tour of the Drafting Settings dialog with the first half of the Dynamic Input settings. And now, the conclusion. (Of Part 4, that is. There's still Part 5.)

I'll pick up again with the "Settings" button for Pointer Input.

There are two pairs of options regarding the format of input for "second or next points", such as when you begin the Move command, pick your first point, and are asked for the second. You can choose between Polar (distance,angle) or Cartesian (x,y) input. The default is Polar, but personally, I'm more likely to know the X and Y values of my distance rather than the distance and angle, so I switched it. Your method may vary. You can also choose here whether you want AutoCAD LT to assume the numbers you're giving it are relative coordinate, or absolute. It defaults to relative, so if you want to move something to (0,0) or another actual coordinate point, you need to preface the input with the pound sign (#). Now you see why you don't have to type @ any more to force relative coordinates!

The second category is about when the input tooltip is visible. The default is that it will show up whenever you're asked for a point, but you can also choose to delay its appearance until you start typing, or force it to display all the time.

The final dialog in the Dynamic Input tab is the Settings dialog for Dimension Input.

Here, you can choose how many input fields you want to see at a time. There are five possible input fields: Resulting Dimension, Length Change, Absolute Angle, Angle Change, and Arc Radius. The default is to see 2 fields at once, but you can also show only one, or any combination of the five.

No matter which visibility setting you choose, you can cycle through all available fields by pressing TAB. Remember than not every field applies in every command or for every object. For example, Arc Radius doesn't apply to lines.

All right, that's it for Dynamic Input! Next up, last but not least...Quick Properties.

Drafting Settings Part 4A -- Dynamic Input

I realized, looking at the Dynamic Input tab of the Drafting Settings dialog box, that it's the most complicated of all the tabs. Not because the topic itself is particularly confusing, but because there are three sub-dialogs in addition to the main window. So this tab will be split up over two posts, in order to minimize information overload.

Dynamic Input was introduced in AutoCAD LT 2006 as a way of moving important command information up into the drawing area, so that you don't have to look down at the command line all the time. It puts floating boxes with command options, prompts, and coordinate information right next to the cursor where it's easily seen.

The main Dynamic Input tab has three areas:

Everything in this main tab has to do with turning Dynamic Input features on or off. First, in the upper left-hand corner, is "Enable Pointer Input". When it's on, you get boxes next to the cursor where you can type in coordinate values.

Next is "Enable Dimension Input". When this is on, and you're creating or grip-editing geometry, the boxes you get are for geometric properties of the object, like length or angle. Dimension Input isn't always available for every command, though, which is why it's often used in combination with Pointer Input.

Both of these options have their own dialog of special settings, but I'll save the details for the next post. (See, now you have to keep reading!)

Last up is "Command prompting and command input". This turns on the tooltips for command-specific prompts and options, such as "Specify next point." When this is on, you can also use the down arrow to see all the available command options on the screen, instead of at the command line. Note: You must have either Pointer Input or Dynamic Input (or both) turned on in order to see the command prompts. It doesn't work all by itself.

The one extra settings dialog I will get into today is the Drafting Tooltip Appearance dialog.

At the top, you can see a preview of what your tooltips will look like -- this applies to all the prompts (Pointer, Dimension, and Command). The "Colors" button launches the same Drawing Window dialog that you can get from the Options dialog, just with the tooltip settings already highlighted. There, you can pick whatever colors you like best for the text and background of the tooltip.

Next are two sliders for size and transparency. The default for both is 0, which means a normal size and an opaque background.

The last setting here asks whether you want all your tooltips to look the same, or whether you want some of them to take their properties from your Windows settings. If you choose "use settings only for Dynamic Input", then your Polar and Object Snap Tracking tooltips will take their colors based on other Windows tooltips, instead of the colors you've set yourself. Like all the settings we've talked about, this is purely a matter of personal preference.

See you next time for more on the options for Pointer and Dimension Input!

Drafting Settings Part 3 -- Object Snaps

Part 3 in our tour of the Drafting Settings dialog box is all about Object Snaps, or "osnaps" for short.

Just like the other two tabs we've seen already, the Object Snap tab has on/off toggles at the top for both the snaps themselves and tracking.

Object Snaps enable you to precisely grab a point on an object, such as an endpoint of a line or the center of a circle, to make sure that geometry that you create or modify ends up exactly where you want it to be. Nothing's more frustrating than receiving a drawing, opening it up, and realizing it that whoever created it didn't use any object snaps. It can mean that "intersecting" lines don't actually touch, or that lines that are supposed to be precisely 6" apart are some fractional amount off from that. That can create some real headaches. (If you've ever seen a drawing like this, you'll know what I'm talking about. If not, be grateful.)

Osnaps can be activated as a one-time snap, or set to be on all the time. The checkboxes in this tab are for the "all the time" osnaps, or running osnaps. The screenshot above shows my personal preference for running osnaps. One osnap that I never set as running is Nearest. There are times when it's an appropriate snap to use, but mostly I'm concerned that instead of grabbing an endpoint or midpoint as I want, I'd end up with a "nearest" point instead. I'm not trying to say that Nearest should never be used as a running osnap, just...be careful.

If you only need a particular object snap once in a while, there are two ways you can get it without turning it on permanently. First, you can type its command line shortcut, usually the first three letters of the snap name (END, MID, CEN, etc.). Or you can hold down SHIFT and right-click, and pick your osnap from the shortcut menu that pops up.

The icon next to each osnap name is the shape you will see when that particular snap is active. The example below shows the endpoint and midpoint icons. To cycle between nearby locations for running osnaps, press the TAB key until you see the icon you want.

Now, when you hover over an osnap location long enough for its tooltip to appear (as I did in the above image), something special happens. That point has now been "acquired", and you can track from it to find another point in the drawing aligned with that one. It's called Object Snap Tracking (or otrack for short), and it's very similar to Polar Tracking -- see Part 2 for more on tracking angles.

To see how this works, imagine that you wanted to draw a line that started at the center of a rectangle. Instead of drawing a construction line from corner to corner, snapping to its midpoint, drawing the line, and then erasing the construction line, let's use Object Snap Tracking instead.

First, I'll hover over the middle of one side of the rectangle until the midpoint icon appears. Then I'll move the cursor up until a dotted line appears, telling me that otrack is active.

Next, I have to go get the other side. Notice that there's still a small "+" at the location of the first midpoint, identifying it as a tracking point.

Finally, when I move my mouse close to the intersection of these two dotted lines, they BOTH appear. I can then left-click to begin drawing my line.

That may seem like a complicated explanation, but I promise you it takes 10 times longer to explain it than it does to use it.

Well, that's enough about Object Snaps and Object Snap Tracking for today. Next up: Dynamic Input!

Drafting Settings Part 2 -- Polar Tracking

The last post began our tour of the Drafting Settings dialog box with information on Grid and Snap settings. Today's installment continues the exploration, this time of the Polar Tracking tab.

Polar Tracking has been around for several versions of LT. It essentially makes certain angles "sticky", so that when you move your crosshairs in a direction that is almost one of your Polar Tracking angles, you automatically snap to that angle. This enables you to draw lines or select points at precise angles, while still granting you the flexibility to draw using other angles as well.

You can turn Polar Tracking on or off with the checkbox at the top of the dialog. Like Snap and Grid, Polar has a function key as well (F10), and can also be turned on and off from the Status Bar.

Once you turn Polar on, you'll want to select your increment angle. This increment determines at what angles the "sticky" alignment paths appear. For example, when the increment angle is set to 90, you will get alignment paths at 0, 90, 180, and 270 degrees. AutoCAD LT provides you with a list of common increments (90, 45, 30, 22.5, 18, 15, 10, or 5 degrees), as well as the ability to add your own angles. The only thing to keep in mind with the additional angles is that they are not automatically incremented. So if you need alignment paths every 7.5 degrees, you could set the increment angle to 15, but then you would have to add all the extras yourself -- 7.5, 22.5, 37.5, etc.

After you pick your increment angle, you can specify how you want that angle to be measured. In the "Polar Angle measurement" section, you can decide that you will always use the absolute value of the angle (relative to 0 degrees, or horizontal), or you can have the increment angle be calculated based on the angle of the last segment drawn. As an example of how the second option works, imagine that you need to draw a line at some random angle, but then need to create many lines that are perpendicular to the first. With the "Absolute" option, this could be rather tedious, but with "Relative", each subsequent line would be automatically perpendicular to the one that came before it. The two captures below help to illustrate this.

The last setting on this tab has to do with Object Snap Tracking, which combines elements of Polar Tracking and Object Snaps (the next tab over). I'll have more on Object Snap Tracking next time, but for today all I'll say is that you can use this radio button to choose whether to have Object Snap Tracking use only the orthogonal (horizontal and vertical) angles, or to use every possible Polar Tracking angle. If your Polar increment angle is set to 90, this setting doesn't make a difference either way, but it will come into play if you're using a smaller increment angle.

Tune in next time for Part 3 -- Object Snaps.

Drafting Settings Part 1 -- Snap and Grid

Today seemed like a good day to start a tour through the Drafting Settings dialog box. It's a pretty involved one, with lots of tabs and sub-dialogs, and it contains lots of stuff to help you configure LT to match the way you like to work.

You can launch this dialog by right-clicking on any icon in the Status Bar (except Ortho) and selecting Settings. Which tab you see first will depend on which icon you selected, but I'll start with the "Snap and Grid" tab.

 

At the top are two checkboxes for activating Snap or Grid; their associated function keys (in this case F9 and F7) are listed next to them in case you don't want to open the box just to turn them on or off.

I'm going to jump down to the bottom of the box first, to the Snap type area. There are three different Snap methods you can use. The first two are Grid snaps, Rectangular and Isometric, and they work along a grid system where the axes are either orthogonal (90 degrees) or isometric (combinations of 30 and 60 degrees). The third snap type, Polar, creates snap intervals along whatever polar tracking angles you happen to be using. It's a little hard to describe, but if you try it you'll figure it out pretty quickly.

Once you've selected a Snap type, you can set your spacing. Since only one Snap type can be active at a time, the spacing for the inactive method is grayed out. In this case, that means that the Polar spacing is inactive. When setting Rectangular spacings, you can choose to force the X and Y spaces to be equal, or you can uncheck the "equal" box and use different values. If you're using an Isometric snap, you only get to pick one value -- the other spacing is calculated based on the value you choose. Same goes for Polar -- you only need one value, since the angle is controlled by another variable (the polar tracking angles).

You can also choose Grid settings on this tab. The Grid is just a visual indicator of distances and spacing -- by itself, it won't help you choose points more accurately, but it will give you a general idea. In typical everyday 2D drafting it shows up as dots, but if you set SHADEMODE to Hidden, the grid becomes lines. It's often used in conjunction with Snap, since you can't see the one and you can't snap to the other.

There are two areas on this tab dealing with Grid settings. Under "Grid spacing", you can set your X and Y spacing (they can be the same or different), and how often you want to see a "major" line, or a line that is darker than the rest. The major line setting only applies when your SHADEMODE is set to Hidden.

Grid behavior controls how the grid looks as you plan and zoom. Turning on Adaptive grid means that as you zoom out, the dots or lines will adjust themselves so you're not left with a completely cluttered screen. Checking the secondary box, to allow subdivision of the grid, means that as you zoom in you get extra indicators, even if you have a wide spacing set. Choosing to display the grid beyond the limits means that it will fill the drawing area, regardless of what the variable LIMITS is set to. Drawing limits used to have more of a practical purpose, when computers were slower, but they're not as widely used any more. Checking this box lets you see the grid anywhere you want to draw.

Well, that's more than enough information for today -- I'll be back next time with everything you wanted to know and more about Polar Tracking.

Space Points Equally Along a Path

If you need to space points or objects equally along a straight line or simple arc, the Array command can provide a quick and easy way to do that. But what if your path isn't a line, arc, or circle?

The Measure command (available at the command line, under Draw-->Point-->Measure, or on the extended Draw panel of the Ribbon under the Point pull-down) places points or blocks at specified intervals on an object.

In the next image, I ran Measure on the spline with an interval of 3. PDMODE is set to 35, so you can see the points.

You can also use Measure to place blocks instead of points. You can choose to have the blocks be inserted with no rotation...

...or rotated so that their horizontal lines are tangent to the path at that point.

Offset to Current Layer

The OFFSET command now includes the option to put the new object on the current layer. (I think it showed up in 2005 or 2006.) Start the offset command, and before you enter the offset distance, type L (for layer). Your choices will be C (current) or S (source). Using the Current option is helpful for offsetting steel beams off a centerline, or footings off a wall, or all sorts of other things.