7 Enclosed Areas. When you have completed this chapter, you will be able to:

Transcription

1 7 Enclosed Areas Our designs so far have consisted entirely of open linework, except for a brief introduction to Fill Attributes on page Closed linework may delineate an Area, such as a section of floor or a sail of a yacht. These Areas may be Filled as in chapter 3, Hatched, Crosshatched, or Patterned using special Cells. Their area may be measured and mass (for a given mass per unit of area), perimeter length and centroid position calculated. We will find a lot in common between the various tools used to work with enclosed areas. For example, the tool settings for Measuring and Patterning are very similar. When you have completed this chapter, you will be able to: Recognize Closed and Open elements Drop a closed element to its component open elements Create a closed element from individual segments Measure areas and derive design information from them Temporarily define areas for patterning Hatch, Crosshatch and Pattern areas Create Associative and Non-Associative patterns Create new closed elements using mathematical combinations of existing closed elements. BEN MicroStation Drafting (Metric Edition) Bentley Education Network 7-1

2 7 Enclosed Areas Closed Elements Closed Elements We have been making these right from the start, as with its default settings the Place Smartline tool closes elements when the first and last data points coincide. However, there will often be situations when elements that were placed separately need to be chained together to form a closed Shape or Complex Shape. We will create a new DGN for our exercises on Areas, placing various elements as we need them and performing area-related operations such as patterning. Create a DGN and Exercise Geometry 1. Create and open a new DGN in our allocated directory named AreaWorks.dgn. Use 2dMetricGeneral.dgn as the seed file. 2. Change the Working Units to Meters and Millimeters with the Coordinate Readout set to Master Units with an accuracy of 3 decimal places (0.123). 3. Set the Line Weight to 2, use solid lines of any color to place two 2m radius circles on the Default level, 12m apart. 4. Snap lines (same attributes) to the circles as shown in Figure Use the PowerSelector to select both lines, then the Trim tool to trim the inside parts of the circles. Now we have 2 arcs and 2 lines that perfectly abut each other, but they are not a closed element. The next job will be to join them. Figure 7.1 Starting Geometry 7-2 Bentley Education Network BEN MicroStation Drafting (Metric Edition)

3 Enclosed Areas The Groups Tool Box The Groups Tool Box All of these tools may be used when we are working with Areas, so this is a good time to introduce them. We have already been introduced to the Drop Element tool in conjunction with Cells on page Drop Element Create Complex Chain Create Complex Shape Create Region Add To Graphic Group Drop From Graphic Group Group Holes Figure 7.2 The Groups Tool Box The Create Complex Shape Tool This tool chains individual elements enclosing an area. Their ends must either meet, or be within a defined tolerance of meeting. The Create Complex Chain tool only differs in that it creates an open Complex Chain element instead of a closed Complex Shape. We will now use this tool to create a Complex Shape from the lines and arcs placed earlier. The tool has a choice of two Methods of creating the shape, Manual and Automatic. The Manual method requires each of the elements to be identified in turn to create the shape, whereas Automatic only requires one element to be identified, then (generally) only one more data point to accept the shape. However, when there are forks in the road of the Automatic chaining process, we are offered one route, which we may accept (with a data point) or reject (with Reset). BEN MicroStation Drafting (Metric Edition) Bentley Education Network 7-3

4 7 Enclosed Areas The Groups Tool Box Manual Method We will create a Complex Shape from the lines and arcs using the Manual method option. This method may be found useful when we are selecting elements to chain from among a large number. This method is less often used than Automatic, so we will work with it in the next exercise once, then change to the alternative. Manually Creating a Complex Shape 1. With AreaWorks.dgn open, select the Create Complex Shape tool, Method: Manual, Area: Solid, Fill Type: None. 2. Identify each of the four elements in order, then accept the shape when all the segments are highlighted. The prompt will read Shape Closed. The Complex Shape just created is a new element and will be created with the currently active element attributes. The attributes of the individual elements are not taken into account. 3. Select another tool and point to the element to display the pop-up info. The Pop-up confirms that the separate elements now form segments of a single Complex Shape. If the segments are identified out of order, or if we Reset before the operation is complete, a bridging element is created. The Status Bar prompt informs us when the operation is successful. Figure 7.3 Creating a Complex Shape - Manual Method 7-4 Bentley Education Network BEN MicroStation Drafting (Metric Edition)

5 Enclosed Areas The Create Complex Shape Tool Automatic Method This is the preferred method to use with the Create Complex Shape tool. It is simpler and faster than the manual method, while still retaining some of the flexibility in element choice that the other method offers. Before we try out this tool we will create a new level and Copy the complex shape to it, then add a second copy to the new level. Preparing the Geometry 1. With AreaWorks.dgn open, create a new level named Making Shapes (see Creating New Levels in the Level Manager on page 3-6). 2. Select the Copy tool, identify the complex shape, then choose Making Shapes as the Active Level in the Attributes tool box, accept the copy with a data point away from any geometry, Reset. 3. Turn Off the Default level, Update the view. Make another Copy of the complex shape on the same level, this time using snaps to position the bottom segment of the copy exactly over the top segment of the original (see Figure 7.4). 4. Select the Drop Element tool, Complex checked, other boxes unchecked. Identify both copies of the complex shape. We now have 4 arcs and 4 lines (2 of them coincident) to use for experiments with the Automatic method. To copy between levels, we click the new level in the Attributes tool box when we are prompted to Enter point to define distance and direction. Use snaps to position the copy with coinciding segments. Both complex shapes are Dropped after the last copy is made. Figure 7.4 Copying Geometry for Chaining Exercise BEN MicroStation Drafting (Metric Edition) Bentley Education Network 7-5

6 7 Enclosed Areas The Groups Tool Box Automatically Creating a Complex Shape 1. With AreaWorks.dgn open and the Making Shapes level Active (ensure that the Default level is Off), select the Create Complex Shape tool, Method: Automatic, Area: Solid, Fill Type: None. A closed element could represent a Solid area, such as a concrete floor. It could also represent a Hole in the floor. While the two elements may look the same, the differences become apparent when we start Measuring Areas and Patterning. 2. Identify the bottom segment of the bottom complex shape. 3. Move the pointer away from any geometry and accept. We will make a complex shape incorporating all 4 arcs and the top and bottom line segments. The prompt informs us there is a Fork and to either accept or reject the direction that the highlight indicates, so Reset if one of the middle line segments have highlighted, otherwise Accept. 4. Continue clicking the Data and Reset buttons as prompted to close the shape as shown in Figure 7.5, finally accepting when the entire complex shape highlights. 5. Delete the 2 middle lines. Use the Data and Reset buttons to steer the highlight around the geometry in the required direction at each fork. After the Complex Shape is closed, delete the unwanted lines. Figure 7.5 Creating a Complex Shape Using Automatic Now we have an area defined by an element, we will start our experiments by measuring it. This will introduce the Measure Area tool, which not only measures area, it displays the perimeter length and will calculate the mass if given a mass per unit area. 7-6 Bentley Education Network BEN MicroStation Drafting (Metric Edition)

7 Enclosed Areas The Create Complex Shape Tool Measuring Area The Measure Area tool not only measures, it performs calculations on the data gathered. It will calculate the mass of an object of constant thickness and its Centroid (the center of mass, assuming a constant mass per unit area). Measure the Area of the Complex Shape 1. Select the Measure Area tool from the Measure tool box, Method: Element, Tolerance: 1%, Mass Properties and Display Centroid both Unchecked. 2. Identify the complex shape, display the tool settings window (press <Ctrl>+<Spacebar>). The area and perimeter measurements are displayed in the bottom panel of the window and in the message area of the Status Bar. 3. Check the Mass Properties box. No need to identify the element again; the Mass Properties window opens and displays the information for the last measurement made. 4. Enter into the Mass Per Area field. The generally assumed density for hardened concrete is 2400 kg/ m 3, thus the approximate mass in tonnes of 1 square meter of concrete paving 100mm thick is MicroStation has calculated that this area of concrete would weigh about 29 tonnes. The approximate nature of this figure is due mainly to the accuracy of the Mass Per Area figure input. The tolerance can be reduced in the tool settings window, but there would be little point when measuring an area of a material as variable as concrete paving. 5. Check the Display Centroid box, identify the element again. The centroid mark will remain until the box is unchecked in the Tool Settings window. The accuracy can be improved (with some speed reduction) by decreasing the tolerance setting. The Centroid indicator persists while the Display Centroid box remains checked. It is Snappable, so it may be used to position other elements. Figure 7.6 Measuring an Area BEN MicroStation Drafting (Metric Edition) Bentley Education Network 7-7

8 7 Enclosed Areas The Groups Tool Box The Group Holes Tool We were introduced to the concepts of Solids and Holes during the exercise Automatically Creating a Complex Shape on page 7-6. Here we created the complex shape as a Solid, representing solid material, as opposed to a Hole, which represents a void in that material. If we need to create a solid with holes, it is necessary to link the Hole elements to the Solid element that they are perforating. Just having the holes inside another closed element is not enough; in a complex design the hole elements could fall inside many closed elements. This is where the Group Holes tool comes in, it Groups the Holes with the appropriate Solid element. In fact it does more than this; where necessary it will convert hole elements into solids and vice versa. This does not mean we can always ignore the Area option when creating closed elements, as they will not always be operated on with the Group Holes tool. Perforating the Solid 1. Place circles at the center of each arc segment using center snaps, with the Diameter option selected and the box checked, constraining the diameter to 2.4m. 2. Select the Group Holes tool, identify the complex shape as the Solid, then each of the circles as Holes, accept away from geometry and Reset as prompted after the last hole has been identified. 3. Repeat Measure the Area of the Complex Shape on page 7-7. The area and mass will be reduced by the amount removed by the holes. The area and mass have changed with the holes being grouped to the solid, but their symmetrical placement has left the centroid in the same place. Figure 7.7 Perforated Complex Shape 7-8 Bentley Education Network BEN MicroStation Drafting (Metric Edition)

9 Enclosed Areas The Group Holes Tool Manipulating Grouped Holes Once a solid and its holes have been grouped, the grouping is permanent, in that the perforated solid is a form of cell, as in Unnamed or Orphan Cells on page 6-2. Any attempt to delete a hole from this grouping will result in the entire cell being deleted. To remove a hole, it is first necessary to Drop the Complex status of the cell. The holes then become individual elements again and may be manipulated as such. Once the manipulations (which includes deletions) and any additions are completed, the solid and holes must be Grouped again. Removing Holes 1. Select the Drop Element tool, Complex checked, other boxes unchecked. Identify the complex shape. Be careful to click only once, or the Complex Shape will be reduced to its individual components. 2. Delete the two lower circles, then Group Holes again as in the last exercise. 3. Repeat Measure the Area of the Complex Shape on page 7-7. The area and mass will be in between the last two measurements. The Centroid has moved down the solid, as there are now holes in the upper section, but not in the lower part. The actual x and y coordinates will depend on the original position of our geometry, but the Centroid has moved down the solid by approximately 160 mm. Figure 7.8 Solid With Holes Removed BEN MicroStation Drafting (Metric Edition) Bentley Education Network 7-9

10 7 Enclosed Areas The Patterns Tool Box The Patterns Tool Box Patterning is the regular placement of lines or cells within a specified area, with the spacing, angle and scale of the patterning elements specified. Patterns are only displayed if they are checked (On by default) in the View Attributes dialog box. There are three separate tools to place a pattern of elements within an area, Hatch Area, Crosshatch Area and Pattern Area. All three create types of patterns, the first with straight lines, the second with two sets of straight lines at different angles, the third creates patterns of cells. The Linear Pattern tool creates patterns along lines, so it is not a tool for working with areas, but we will introduce it later on in this chapter just the same. Hatch Area Crosshatch Area Pattern Area Linear Pattern Show Pattern Attributes Match Pattern Attributes Delete Pattern Figure 7.9 The Patterns Tool Box The Hatch Area Tool This is the tool that places equally-spaced parallel lines to pattern an area. We will start by using it to pattern the area of the perforated complex shape we have been working on in the last exercises, then we will use it to create other areas of pattern. Element Method We will be patterning the same elements many times over in the following exercises, so we will also need the Delete Pattern tool from this tool box. Delete Pattern differs from the ordinary delete tool in that it will always remove only the entire pattern, whereas the ordinary delete tool may remove patterning and the patterned element altogether. Hatching the Complex Shape 1. Have AreaWorks.dgn open, the Making Shapes level active (and the only one displayed). 2. Select the Hatch Area tool, Method: Element, Spacing:.3m, Angle: 45, Associative Pattern: Checked, Snappable Pattern: Unchecked Bentley Education Network BEN MicroStation Drafting (Metric Edition)

11 Enclosed Areas The Hatch Area Tool It is usual to make patterns non-snappable, otherwise there are so many snap points that it becomes a problem to find the right one. 3. Identify the complex shape, then snap to the connection between the left-side arc segments to pattern intersection point. The element is hatched; now we can readily see what is a Solid and what is a Hole. Note that a pattern line passes through the point we snapped to. 4. Move the element a short distance - note that the pattern moves with it, then Undo the move. This is an effect of Associative Patterning; whenever the element is manipulated or modified, the pattern automatically updates. 5. Select the Delete Pattern tool, data point anywhere on the pattern (or on the Associated patterned element) to delete the hatching. 6. Repeat the hatching as before, but this time Uncheck Associative Pattern before doing so. 7. Move the element again (this time the pattern is left behind), Undo the move and delete the pattern prior to the next exercise. Delete Pattern Associative Pattern forms a permanent association between the pattern and the patterned element. Without this association (Associative Pattern unchecked), the hatching lines are all individual elements and do not change when the patterned element is modified or manipulated. Figure 7.10 Hatching an Element BEN MicroStation Drafting (Metric Edition) Bentley Education Network 7-11

12 7 Enclosed Areas The Patterns Tool Box Flood Method This method patterns an area enclosed by a set of elements. These may be any type of element that will define an area in combination with other elements, they may be lines, curves, simple or complex shapes, in fact any form of linework. We need an additional element for the following exercises, so we will copy the shape from the Default level once more, then manipulate it into position for more patterning exercises. Prepare More Patterning Areas 1. With AreaWorks.dgn open, turn the Default level On, Copy the complex shape from Default to Making Shapes (we did this before when Preparing the Geometry on page 7-5). It does not matter if Making Shapes is already Active, clicking it in the Attributes tool box will still direct the copy to it. 2. Turn Default Off; Rotate the copied element about its center (center snap for the pivot point) by 90 (the 2 points method with AccuDraw is quickest, see page 4-19). 3. Move the element vertically to align its center with the connection of the arc segments (see Figure 7.11). We can use Center snap on the element we are moving, but not on the other group, as the center snap location is affected by the grouping of the holes. We use Smart Lock and a Keypoint snap to find the position to move to. First Rotate the complex shape copied from the Default level then move it vertically to align its center with that of the perforated element perimeter. Figure 7.11 Adding More Geometry 7-12 Bentley Education Network BEN MicroStation Drafting (Metric Edition)

13 Enclosed Areas The Hatch Area Tool Hatching Using Flood Method 1. Have AreaWorks.dgn open, the Making Shapes level active, Default Off. 2. Select the Hatch Area tool, Method: Flood, Spacing:.3m, Angle: 45, Associative Pattern: Checked, Snappable Pattern: Unchecked. 3. Data point in the area to the left of the vertical complex shape, then Manually snap to the connection between the left-side arc segments. When using this method, we need to use the Tentative button to snap. The element is hatched as soon as we accept the snap. With these settings, the holes are ignored, as the flood only sees elements that block off the flow. 4. Move the vertical complex shape a short distance within the width of the other element, note the effect. Associative Patterning still works with Flood, the pattern updates to follow the change in the boundaries. This method is very useful to pattern areas between a set of elements, none of which need to be closed. 5. Undo the move, then Undo the pattern (or Delete Pattern). When a data point is placed inside the area to be flooded, a boundary for the proposed area is displayed. Patterning takes place when the proposed area is accepted. The pattern is associated with the bounding elements. Figure 7.12 Associative Flood Hatching BEN MicroStation Drafting (Metric Edition) Bentley Education Network 7-13

14 7 Enclosed Areas The Patterns Tool Box 6. Select the tool again, same settings as above, but this time click the down arrow to open the additional panel of the Tool Settings window and check the Locate Interior Shapes box. 7. Hatch the area again, placing the data point to start the flood outside the hole but inside the complex shape as before. The hole is kept clear this time. 8. Delete the pattern, place a.6m radius circle concentrically within the hole. 9. Select the Hatch Area tool, leave the settings as before except this time check the Alternating Area box in the additional panel, hatch the same area as before. With this setting, the hatching alternates On and Off with alternate areas within areas. 10. Undo the pattern, then Undo the inner circle placement. Figure 7.13 Incorporating Internal Areas The Crosshatch Area Tool This tool only differs from Hatch Area in that it places a second set of hatching lines, which have separate spacing and angle settings. Apart from this, all of the tool settings are the same with both tools, so we will not repeat the methods used in the earlier exercises. Additionally, all of the methods used in the following exercises with the Crosshatch tool will work in a similar way if we used the Hatch tool. Intersection, Union and Difference These classic Boolean symbolic logic operators are Methods available with the Area related operations such as patterning. We will experiment with them using Crosshatching Bentley Education Network BEN MicroStation Drafting (Metric Edition)

15 Enclosed Areas The Crosshatch Area Tool Crosshatching with Symbolic Logic 1. Have AreaWorks.dgn open, the Making Shapes level active, Default Off. 2. Select the Crosshatch Area tool, Method: Union, Spacing:.3m and.6m, Angle: 45 and -45, Associative Pattern: Checked, Snappable Pattern: Unchecked. 3. Identify the 2 complex shapes in turn, accept (the region proposed for patterning is displayed) then Reset to place the crosshatching. We have only identified 2 shapes, but there is virtually no limit to the number of closed elements included. 4. Undo the hatching, select the Crosshatch Area tool again, changing the Method to Intersection. 5. Identify the 2 complex shapes, accept the combination (note how the region for patterning is displayed), Reset to place the crosshatching. The only area patterned is where the shapes intersect. 6. Undo the hatching, Move the vertical shape to overlap one hole. Select the Crosshatch Area once more, Method: Difference. 7. Identify the larger shape (which is to be the base), then the vertical shape to subtract from this, accept the combination and Reset to place the crosshatching. Take care to identify the element we need as the primary area, then the elements to subtract from this. 8. Undo the pattern (or Delete Pattern) and the last Move operation. When we accept (away from any element) the combination, the region to be patterned is displayed. Holes are subtracted with Intersection and Difference. Figure 7.14 Hatching Using Symbolic Logic BEN MicroStation Drafting (Metric Edition) Bentley Education Network 7-15

16 7 Enclosed Areas The Patterns Tool Box Standalone Patterns We may need to create a pattern without any elements, for example to show a pattern on a large object without it covering the whole lot and possibly hiding other geometry. We have two methods for this operation, Fence and Points. Patterning Without Boundary Elements 1. Have AreaWorks.dgn open, the Making Shapes level active, Default Off. 2. Place a Fence, Fence Type: Circle (Fence Mode has no effect with this tool) in a clear area, make the fence circle smaller than either shape. 3. Select the Crosshatch Area tool, Method: Fence, Spacing:.3m and.3m, Angle: 30 and -30, Associative Pattern: Unchecked, Snappable Pattern: Unchecked. 4. Accept the pattern with a data point, click Place Fence to remove the fence, Update the view. The pattern has no boundary; any attempt to manipulate it will show it is composed of many individual lines. 5. Undo the hatching, replace the fence, select the Crosshatch Area tool again, this time checking the Associative Pattern box. 6. Accept the pattern with a data point; remove the fence, Update the view. The pattern is bounded by a multi-sided shape, with a color, line style and line weight all of 0. The pattern and its boundary may now be manipulated as one, including being deleted with the ordinary Delete tool. 7. Delete the hatching. While we used a Circle fence type, we could use a shape, block or any other type of fence. The pattern is fully standalone if we do not check Associative Pattern. An associated Shape element is automatically created when Associative Pattern is On. Figure 7.15 Patterning a Fence Area 7-16 Bentley Education Network BEN MicroStation Drafting (Metric Edition)

17 Enclosed Areas Patterning With Cells 8. Select the Crosshatch Area tool, Method: Points, Associative Pattern: Off. 9. Place an imaginary shape with data points, Reset when the last vertex is placed. If we chose to place this as an Associated Pattern, an associated shape would have been generated, as it was with the Fence method. Figure 7.16 Patterning Between Points Patterning With Cells This is where the patterns become more lifelike. There are hundreds of pattern cells supplied with MicroStation and there is no limit to the number of pattern cells we can create for ourselves. A pattern cell is really no different in the way it is created or stored than any other cell. Whilst we can make a pattern out of any cell, specialized cells will normally be designed for this function. Point type cells (see Graphic Vs. Point Type Cells on page 6-30) are often used for patterning, as they take on the level and symbology active when the pattern is being created. This gives us full control of the attributes of the pattern, instead of the creator of the pattern cell. The pattern cells are placed as Shared Cells (see page 6-26), thus once a pattern is placed for the first time, the definition of the cell remains in the DGN. This enables the cell to be used again without an attached cell library, provided Use Shared Cells is checked in the Cell Library dialog box. We will start by using a small selection of the cells supplied with the application for the first exercise, then we will experiment with our own. BEN MicroStation Drafting (Metric Edition) Bentley Education Network 7-17

18 7 Enclosed Areas The Patterns Tool Box Patterning an Element 1. Have AreaWorks.dgn open, the Making Shapes level active (and the only one displayed). Set all of the symbology attributes to Select the Pattern Area tool, click the magnifying glass icon beside the Pattern Cell field to open the Cell Library dialog box. Attach BENMD.cel from our allocated cell directory (File > Attach from the dialog box menu). 3. Highlight RANRBL (a rubble wall patterning cell), click the Pattern button to make it the active patterning cell, close the dialog box. 4. Return to the Pattern Area tool, Method: Element, Scale: 1, Row & Column Spacing: both 0, Angle: 0, Tolerance:.3m, Associative Pattern: Checked, Snappable Pattern: Unchecked. 5. Identify the perforated complex shape, then data point anywhere to define the pattern intersection point. The rubble pattern is placed, but the Tolerance setting of.3m is too great. Note that the pattern does not follow around the arcs and circles very closely, in fact it may be as much as 300mm away in places. 6. Change the Tolerance setting to.03m (30mm). Undo the previous pattern, repeat the Pattern Area operation. The closer tolerance improves the result. Technically, the pattern actually follows an invisible shape with a series of straight segments, approximating the curves. The Tolerance setting defines how far the segments are permitted to depart from the curves. The pattern follows curves with a series of straight lines. The Tolerance setting does not matter for straight sections of boundary, but it needs to be considered with curves. Figure 7.17 Patterning an Element 7-18 Bentley Education Network BEN MicroStation Drafting (Metric Edition)

19 Enclosed Areas Patterning With Cells How Pattern Cells Fit Together We used a Row Spacing and Column Spacing of 0 when we patterned the complex shape in the last exercise. This setting differs from the Spacing settings with the hatching and crosshatching tools, where it relates to the distance between each repeat of the (line) pattern. With cells, the row and column spacings are usually left at zero, as the distance between the repeats of the cell is set by the maximum x and y dimensions of the cell. Any spacings appear as gaps between the cell repeats. We will experiment with more patterning, using our familiar AircrT cell. Investigate Cell Patterns 1. Have AreaWorks.dgn open, the Making Shapes level active (and the only one displayed) and all of the symbology attributes set to 0. Turn Fill Off in the View Attributes dialog box. 2. Use the Place Block tool to place a.25m wide by.2m high rectangle in a clear area of the view. Use Window Area to enlarge the display. 3. Select the Pattern Area tool, click the magnifying glass icon beside the Pattern Cell field to open the Cell Library dialog box. Attach our Student(nn).cel from our cell directory. 4. Highlight AircrT, click the Pattern button to make it the active patterning cell, close the dialog box. 5. Return to the Pattern Area tool, Method: Element, Scale: 1, Row & Column Spacing: both 0, Angle: 0, Tolerance:.1, Associative Pattern: Checked, Snappable Pattern: Unchecked. 6. Identify the block just placed, then snap to the lower-left corner to define the pattern intersection point. The cells are placed wingtip-to-wingtip, with the nose of one aligned with the rear of the tail of the next. The pattern cells each occupy a space defined by their maximum x and y dimensions; no geometry from another cell can enter this space. Note that the sweep-back on the tail prevents the cell behind touching the one in front. Figure 7.18 Minimum Pattern Cell Spacing BEN MicroStation Drafting (Metric Edition) Bentley Education Network 7-19

20 7 Enclosed Areas The Patterns Tool Box 7. Change both the Spacing settings to 0.03m (30mm). Repeat the Pattern Area operation. There is no need to delete the existing pattern, the new one will overwrite the old. Let us assume that this spacing is just right and we want to modify the cell so that it always patterns with this spaced out effect, but without the need to remember the spacing each time. To arrange this, we would need to increase the space occupied by each cell, but without adding any visible geometry. We can do just this - Active Points (page 5-38) are invisible when they are in Cells used in Patterns. We will make a version of this cell to use for patterning, with an Active Point placed at the top-left,.03m above and behind the existing cell. We could edit the cell in its library, but then it would not be usable as a terminator any more. Whilst active points are invisible in patterns, they are not in any other type of cell placement. We will place the cell, Drop it and use the geometry to create a new cell, in a similar way to when we changed AircrT to a Point type cell on page Creating a Spaced Patterning Cell 1. With AreaWorks.dgn open, window about a blank area and place the cell AircrT as an ordinary cell placement (Shared Cells unchecked). 2. Select the Drop Element tool, check Complex (all other boxes unchecked), identify the cell just placed. 3. Set the Line Weight to 10; select the Place Active Point tool, Point Type: Element, all fields empty. 4. Move the pointer over the left-upper tail vertex (indexed), set the AccuDraw Origin temporarily to this point (O shortcut). 5. Move the pointer to the left, key-in.03 (the x value locks), then move the pointer over the upper wingtip until AccuSnap indexes, set the AccuDraw origin level with this point (O shortcut again). At this stage we have the point positioned 30mm to the left of the shape and temporarily at the height of the top. 6. Move the pointer back over the AccuDraw compass and directly upwards, key-in.03, accept. Set the Line Weight to 0. We have now placed an active point exactly 30mm to the left and above the extremities of the shape. 7. Place a cell Origin anywhere (say between the active point and the tail), then select the point and the shape with the PowerSelector. The position of the cell origin is not critical with cells that are only to be used in patterning. 8. Open the Cell Library dialog box (Element > Cells), click Create. 9. In the Create New Cell dialog box, name the cell AircrP, describe it as For spaced patterning, choose the Point option, click Create. The new point type cell will appear in the Preview panel. Remember to clear the element selection before proceeding Bentley Education Network BEN MicroStation Drafting (Metric Edition)

21 Enclosed Areas Patterning With Cells 10. Highlight the new cell and make it the Pattern cell; select the Pattern Area tool, Row and Column Spacing: both 0, the rest of the settings as used in the preceding exercise, pattern the rectangle. The pattern will be spaced in the same way as when we included Row and Column Spacings, but now it may be placed consistently with the default settings. We start to place the Active Point with AccuSnap indexing the pointer to the leftmost point then set the Origin back by.03. The next Origin setting is controlled by Smart Lock then the point is placed.03 further upward. Select the shape and active point, snap a cell origin to the active point, then create the cell. The active points do not show up in the pattern. Figure 7.19 Patterning Cell With Spacing Points BEN MicroStation Drafting (Metric Edition) Bentley Education Network 7-21

22 7 Enclosed Areas Creating Region Elements Creating Region Elements The Create Region tool is in the Groups tool box, along with Create Complex Shape. Like Create Complex Shape, Create Region creates complex shapes from other elements, but using different techniques. This tool creates a complex shape from a defined Area, the methods to define which are already becoming familiar. We will find a common set of Methods if we examine the Tool Settings windows of Create Region, Measure Area, Hatch Area, Crosshatch Area and Pattern Area. We have been introduced to all of these methods, but not in conjunction with all of the tools. They operate with total consistency between the tools, so if we can use them with one, we can use them with all. Figure 7.20 shows just how similar the choices of Method are when dealing with Areas, even when the tools are taken from three different tool boxes. Figure 7.20 Methods of Defining Areas The Create Region Tool Complex shapes are created by this tool from an existing Area. The particular area may either be defined by the symbolic logic operators or by flooding the region. The new element s symbology will be that which is active at the time the tool is used, unaffected by the original elements. The original elements may either be kept, or replaced by the new Region element. We will also be introduced to the SmartMatch tool, which is used to set the active attributes to match those of an identified element. We will Match the attributes to one of the complex shapes, then place a line across one of the shapes with these attributes Bentley Education Network BEN MicroStation Drafting (Metric Edition)

23 Enclosed Areas The Create Region Tool Creating Regions 1. With AreaWorks.dgn open, window about the crossed complex shapes; delete any residual patterns as necessary. 2. Select the SmartMatch tool from the Change Attributes tool box, identify one of the complex shapes. 3. Place a line diagonally across the larger complex shape, as shown in Figure Choose different symbology for the Region elements, selecting a heavier line weight and a contrasting color to the original elements. 5. Select the Create Region tool from the Groups tool box, Method: Intersection, Fill Type: None, Keep Original: Checked. 6. Identify the 2 complex shapes in turn, then Reset to create the complex shape. 7. Move the new shape to the side of the originals (if the wrong element starts to move, Reset to select another). 8. Repeat steps 5, 6 and 7 with the other 2 logical methods. Once an element has been identified, it is not available to be identified again. This line will be used with a Flood method operation. The region-generated Intersection shape may need to be moved before we can see it. The proposed region is displayed as subsequent elements are identified. Figure 7.21 Creating an Intersection Region BEN MicroStation Drafting (Metric Edition) Bentley Education Network 7-23

24 7 Enclosed Areas Creating Region Elements 9. Choose the Flood method, Locate interior shapes: Unchecked, Max(imum) gap: 0, data point in the left section of the larger complex shape beneath the diagonal line. 10. Accept the flood generated shape, move this shape away from the originals. Note that the exposed part of the perforation circle is still used to shape the region, even though Locate Interior Shapes is unchecked. The Flood cannot flow all around it as it could when we used this method for hatching on page Union Intersection Flood The Flood region is completed with a data point, not Reset. Difference (2 shapes) Figure 7.22 Creating Regions 7-24 Bentley Education Network BEN MicroStation Drafting (Metric Edition)

25 Enclosed Areas Linear Patterning Linear Patterning Cells can be placed along a line, replacing the original line. This is an alternative to Custom Line Styles, where special line styles are created (not included in this course). The guide lines can be any linear element, including curves. The length of pattern elements may not divide equally into the length of the line, so there are Cycle options in the tool settings to cope with this situation. The options are: Truncated - Complete - Single - Multiple - The end pattern element is truncated to the end of the linework being patterned The scale of the pattern cell is adjusted as necessary so that only complete instances are placed Placed with one cell instance on each segment Similar to Complete, except that the scale of the pattern cell is adjusted to only place complete instances on each Segment of the linear element being patterned. Create a Linear Pattern 1. Open AccuWorks.dgn from our dgn directory; use the Level Manager to create a new level named Linear Patterns (see Creating New Levels in the Level Manager on page 3-6). 2. Make the new level Active, turn Off all others. Use the Place SmartLine tool to place a complex chain as shown in Figure 7.23 (We were introduced to Rounded Vertices on page 5-4). 3. Make 2 copies of the complex chain to one side, 1.2m apart (making 3 elements in total). Figure 7.23 Complex Chains for Linear Patterning BEN MicroStation Drafting (Metric Edition) Bentley Education Network 7-25

26 7 Enclosed Areas Linear Patterning 4. Select the Linear Pattern tool, Cycle: Single, select AircrT as the Pattern cell (attach our Student cell library if necessary), leave the Scale and Tolerance at the default values. 5. Identify one of the complex chains near one end, then again near the opposite end to Define direction and complete the pattern. A single cell replaces each segment of the complex chain, taking on the attributes of the chain. The cells are placed at the midpoint of each segment, as shown in Figure A dashed version of the original line has been shown in the illustration to show the relative positions of the cells. 6. Change the Cycle setting to Multiple, identify both ends of another copy of the chain. Multiple places a complete number of complete cells in place of each segment, spacing them out to fill the segments. 7. Change the Cycle setting to Complete, identify both ends of the third copy of the chain. Complete places a complete number of cells in place of the whole element, changing the scale as necessary to exactly match the length of the element. Zoom in to note the differences. Single Complete Multiple Figure 7.24 Linear Patterning 7-26 Bentley Education Network BEN MicroStation Drafting (Metric Edition)

27 Enclosed Areas Design Problem - Design a Concrete Wall Design Problem - Design a Concrete Wall Create a new DGN in our allocated directory named Tilt Up Wall, using the seed file 2dMetricGeneral.dgn. Design a wall component intended for precast concrete construction as specified in Figure 7.25, on a level named External Walls. After completing the design to the stage shown (excluding the patterning) in Figure 7.25: Measure and record the area and the mass of the wall component Place a 1m diameter hole in the wall 300mm from the top, to be used as a lifting point. This is to be positioned laterally to ensure that the base of the wall shall be horizontal when lifted by a crane from this lifting point. Recalculate the area and mass and record, then pattern the wall. Hints - we find: Measuring Area on page 7-7 and The Place Ellipse Tool on page Pattern with the cell CONCRT from the BENMD cell library. Material: 100mm thick reinforced concrete, 0.24 tonnes per square meter. Figure 7.25 Pre-cast Wall Component BEN MicroStation Drafting (Metric Edition) Bentley Education Network 7-27

28 7-28 Bentley Education Network BEN MicroStation Drafting (Metric Edition)