Problem based learning

One approach to learning to use CAD software such as GardenCAD for garden design and landscape use is to adopt what is known as problem based learning. Some users are more comfortable with this approach than with traditional learning methods; they see a real job being developed.

It is important though to point out that we have some more conventional learning materials set out in subsequent modules.

We will imagine that we have been given the job of designing a garden for the backyard of a house. This is a real job, the house happens to be in Canberra in the Australian Capital Territory. We have visited the site and made a 'mud map' showing our site measurements. This mud map is shown in the figure below.

This approach will not suit everyone. If you want to learn to use the software in a more conventional way, skip this module and take the others in sequence, learning about the Draw tools, the edit tools, the settings etc. before you begin to lay out a proper job.

Mud map

Here is our mud map.

Mud map showing measurements and 'scribbled' design ideas.

Setting out the site boundaries and location of buildings

Preamble

The units in GardenCAD are reported in millimeters. We will start by opening a template. The value of this is that many of the settings we will require have been made - layers, linetypes etc.

Locate back boundary

Open template, set layer and draw back boundary.

File>New.

Open Drawing DESIGN_TEMPLATE from the exercises folder.

Click alongside the layer name (on the black down arrow) and set layer AL_SETOUT as current. Just click on the layer name and it becomes current.

Check that colour of the layer is set to red. A red block should show in the properties strip and the word AL_SETOUT should appear in the strip.

Make sure that Tracking s turned on by double clicking on the word Track in the status line (the strip at the bottom of the screen.

Select the Draw drop down menu and choose the Line tool (we will use the notation Draw>Line).

Click with the left button of the mouse somewhere at the top left of the screen

Swing the mouse until the line extending from your start point is horizontal and the beige block shows. this indicates that you are drawing a horizontal line.

The back boundary of the site is 7 meters. Everything in the building trade is in mm so type 7000 for the length of the line and click the right mouse button.

Check your work by selecting the line, right clicking and make sure that the line is indeed 7000 units long.

Checking that our first line is correct. select the line and right click to pop up the Properties dialog box.

Locate dwelling position

Next we locate the position of the dwelling and deck.

Offset back boundary to find house location and edge of deck

Double click on the work set in the status line.

Set Object snap on an grips.

Click Modify>Copy.

Watch the prompt in the Command area at the bottom of the screen. It prompts you to select the object to copy. Select the line with the left mouse button (the horizontal line at the top of the screen which represents the back boundary of the site.

Press the right mouse button.

Swing the mouse pointer under the horizontal line in the direction of the copy. Make sure that the beige tracking button shows. When it does, type the distance (7500).

Click the right mouse button and the line will be offset (copied parallel below).

Edge of deck

Repeat the copy process to make a new line offset 1800 mm up from this new line. Your screen should look like this:

Checking the distances after offsetting lines.

Check that you have set things out correctly with the Information>distance tool. This is a very important step because if you get things wrong at this initial stage, errors are compounded as you draw more.

Locate dwelling edge

Next we locate that portion of the house which run toward the back boundary from the deck. The line of the house finishes 0.5 m from the back boundary.

Locate house

Offset the back boundary 0.5 meter (500mm).

Draw a line from the bottom left of the drawing (Point A) to the end of the back boundary line (Point B) as shown below.

Draw the vertical line representing the house footprint. I have extended the house foot print around the corner. You will not see this initially - point B will be an end point.

Draw the short line representing that part of the house to the left of the line you have just placed.

Drawing the northern boundary

The north boundary of the site runs at an angle as shown on the mud map. We now need to locate it. The back of the house is 8000mm long at this point, not 7000 as we have drawn it.

Locate northern boundary of the backyard

Extend the bottom line (the house edge) to 8000mm.

Rather than using the copy offset, simply click on the line, select properties and change the length from 7000 to 8000.

Click on the line, right click and pop up the properties box. Change the length from 7000 to 8000.

Then draw from the end of that line (Point C) to the end of the back boundary (point D).

Modify>Extend the line of decking to this new boundary.

Move entities to appropriate layers

The site boundary layout is complete. It is time to move entities to their correct layers.

Move entities to correct layer

Select the right and back site boundaries with the left mouse button.

Right click and select Properties with the left mouse button.

Click alongside layer AL_BOUNDARY and set that as the layer for these two entities.

Close the Properties box. the entities should show blue.

Apply decking

We will now illustrate the power of CAD software by applying some hatching representing decking.

Draw decking

Select Draw>Hatch

Scroll down to the hatch list to the hatch pattern Engrave. make sure that the angle is zero and the scale is set to 100.

Choose the pick points option and click into the area in which you want the hatching to take place.

GardenCAD will radiate out and find the boundary.

Right click to accept and the hatch pattern will be applied.

The hatch pattern dialog box.

Draw and copy pergola support

This deck is covered. We will now draw the posts which supports the shade structure over the decking.

Draw decking support poles.

Select Draw>Rectangle. Zoom in on a convenient area of the drawing.

Draw a rectangle 110 X 110 mm anywhere on the screen.

Use the @110,110 sequence to draw the rectangle.

Offset the vertical line of the house by 1400, then by 3900, then by 6300, then by 7600 to set the position for the poles.

Extend the newly offset lines through to the back boundary. Erase the horizontal line left when we offset the back boundary 500 mm.

Double click on the Set option in the status line and set the object snap to intersection. Leave the grips option on. Make sure that the set grips object snap is on.

Copy the rectangle across as shown in the movie.

Adjusting the entity snap options ready for copying the rectangles (posts).

Hatch Posts and extend to back boundary

We will as part of our design, reflect these posts into the backyard area to tie out design to the house.

Draw decking support poles.

Hatch all the rectangles representing poles. (It would have been better to have done this before the copy step.)

Switch the drawing colour to yellow.

Make sure that the Set option for entity snap is still set to intersection and grips.

Draw construction lines lines as shown in the movie (labelled [confusingly] point F and point G).

Now select the Mirror command and the objects that you want to mirror, when asked for the first point of the mirror line, select from mid point to midpoint. Keep the shift key depressed as you effect the mirror operation and the rectangle representing the base of the poles will be reflected against the rear boundary.

Create elevation views of support poles

This is a good opportunity to create and elevation view of these poles on the back boundary.

Create elevation views

As shown in the movie, draw a horizontal line above the rear boundary. Make sure that tracking is on when you draw the line so the line is at zero angle.

When you have drawn the line, check that its angle in the XY plane is indeed zero by selecting it, right clicking and pop up the Properties dialog box.

Use Modify>Extend and extend the yellow construction lines up from the center of the plan view of the poles (to points H, I and J).

Now offset the horizontal ground line by the height of the poles (2200) and this line by 200 to give the thickness of the 'fascia'.

Copy all three red rectangles up to points H, I and J as shown in the movie.

Select Modify>Explode and break up each of the red post bases. This breaks each up into its constituent parts.

Double click on the set option in the status line and set perpendicular on.

Now select Line and draw from the edge of the rectangle perpendicular to the fascia board as shown in the movie.

Repeat so that all the elevation views of the poles are drawn.

A small problem

If you cannot complete all three poles easily, play the movie below.

Copy a pole as shown in the movie.

Trim elevation view

We need to clean up our elevation view by trimming off overhanging entities.

Trim elevation view

Extend the top and bottom lines of the elevation.

Now use the trim command to slice off the overhanging entities.

Trimming off the overhanging entities on the elevation view.

Draw steps

The decking is raised above the level of the backyard. There are a set of existing steps leading from the deck to the lower area (our design space). Now is a good time to do that. You can see that we are concentrating on generating a base plan.

Draw steps.

The steps are 1500 mm long leading from the decking to a lower level.

Offset the edge of the decking by 1500.

Make sure that the intersect object snap on.

Use the rectangle command to draw the plan view of the steps as shown in the movie. hatch the steps with the same pattern, but use a scale of 200 instead of 100. This gives a series of steps.

Draw steps.

Draw existing path

An existing curve pebbled path runs from the side boundary to the base of the steps. The client wishes to retain this path. The path is composed of some quite complex shapes. We will use the polyline (or flexible line) command to create the curves of the path.

Draw path edge

We need some construction lines to help denote the path edge. We took some measurements while on site and these can be used to set our path edge.

Turn off the perpendicular object snap setting.

Offset the edge of the decking by 1600 (the maximum bulge value), by 1450 (the point of inflexion) and 450 minimum width.

Click on these three offset lines and change their colour to cyan.

Set object snap to Near and Intersect. Clear the grips setting.

Choose the Polyline command and draw the path edge as shown in the movie.

Offset and edit the polyline

Offset (copy) the path, then use grips to edit the path edge.

Offset (copy parallel) the path edge 800 mm to create the path. Keep tracking on and copy at 90 degrees.

If required, click on the blue handles and drag into position to set the new edge correctly.

Locate existing tree

The client has identified one tree which she wishes to retail. This tree is 3200 mm from the edge of the `decking and 1800 in from the line of the dwelling.

Locate tree

Offset the line representing the decking edge by 3200.

Offset the edge of the dwelling 1800.

Locate a circle diameter 1000 at this intersection.

Remove any construction lines not required.

Create a new layer called L-CONSTRUCTION and move any lines not required to that layer.

Turn the layer L-CONSTRUCTION off.

The base plan is complete.

Save your design in the jobs folder. things do't look too exciting at this point, but you have an accurate model - a base plan with which to work. This drawing can be plotted at any size on any size sheet of paper

The completed base plan.

The new design

The next and by far most interesting stage is to apply our design elements. Instead of adding directly to the design, we will develop some separate drawings and then place these directly into our base plan.

We have mentioned that we want to specify the location of a child's cubby house, an outdoor entertaining area for adults, a sand pit play area etc. It is better in the long run to complete some of these aspects of the design as separate drawings. They can then be used again.

Adult entertaining area

The client has requested an outdoor adult entertaining area. because we have a design in a block library, we can show her what we have in mind here quite easily.

Perspective view of seating area.

Plan view of proposed adult seating area.

Examine adult seating area

Open the design LShapedSeat.

Right click on the desk top and set the grid to 410 (both X and y) Set snap on.

Click Draw>Insert block and insert the 400mm paver block as shown in the movie.

Save the drawing in your jobs folder. Later we will insert this whole drawing into our base plan.

Examine any other drawings that you can find in the blocks folder.

Here is a partial list: CrushedRockPathway, RockeryWall, Tree&ShrubPlanting On Slopes, Cubby House.

Tree and shrub planting on slopes.

We may not use any of these in our current design, but it is good to know that they are there.

The Cubby house

The client has a small child. we need to design a cubby house and sandpit. The sandpit needs to be in line withe view from the kitchen while the cubby house (placed on a rubberised safety surface) will be used as the child gets older.

Back to the design

It is now time to re-open our base plan and begin our design work. We will be able to build up some geometry quite quickly because the blocks (symbols) that we have just looked at will be laced as single entities - we will not have to draw them in.

Begin the design

Open your base plan drawing.

Add plants from your symbol library to complete the design.

Review

Please review your knowledge of the material in this module before progressing to the next stage. If you are taking this course by CD-ROM based learning, click the back button on your browser. If you are taking this course by broadband earning, click the Resources link at the top of the page.