Developing Site Plans in 2D Rhino + Illustrator



This workflow explores the best practices in tracing existing maps for generating site plans. Some of these steps may also be helpful for tracing existing drawings, or re-working drawings that may have lost vector information. Emphasis is placed on precision, organization and efficiency.
Uses Tool(s) Rhinoceros , Illustrator CS5

Similar to this workflow that shows how to trace existing 2D drawings, this workflow emphasis proper techniques for tracing an existing raster image for purposes of analysis or presentation. These could also be helpful in cases of re-creating digital models from working drawings for other purposes like modeling making or digital analysis. This workflow emphasis organization, precision and making good judgement calls when tracing - such as alignment and consistency.


Bringing in Artwork to Rhino

Within this workflow, we will be tracing aerial raster images of a site located in downtown San Francisco. These may include the following image file types: .bmp, .tga, .jpg, .jpeg, .pcx, .png, .tif, and .tiff. Certain file types, such as .pdf, may include both vector AND raster information - therefor you may want to try opening the file in Adobe Illustrator to see if any of the linework is already in vector form.

After opening Rhino, the first step to tracing a drawing is to bring the rasterized image into the workspace. We will be working in the TOP view for the entirety of this drawing.

Use the command "PictureFrame" to place the image. A crosshair icon will appear. If you type "0,0,0" the PictureFrame will begin at the origin of your document. A rectangular bounding box will appear. Drag to a relatively appropriate scale. If you hold SHIFT while dragging, the image the bounding box will remain orthogonal to the X or Y axis. Note: We will be accurately scaling the raster image next.

Picture Frame

2-picture frame-hybridmap.JPG Picture Frame brings the image file in as a textured surface and is therefore an object in the workspace, visible to all viewports. To edit the image, select the object as usual. If the image is not showing up, change the display mode for just this object with the command SetObjectDisplayMode . Change to "Rendered".

Scale the Image

Before actually tracing the image, it is important to size it correctly so that as you draw, you can reference specific measurements and have an understanding of what scale drawing you are making. Check the Units by typing Units in the command line. Make sure that the units you desire are those of the actual building scale (NOT the drawing scale - we will export to this scale later). It is also nice to have the Decimal Display set to Feet & Inches.



Find a reference of scale on the image. For the San Francisco map we just placed, lets use on of the adjacent edges of the block that our site is located within. The block that our site is located (between Minna & Natoma) is 155 feet wide.

Type Line and place your crosshair on the upper left corner of the leftmost lot and Type 155 . This will insure that our line is 155 feet long. Now move the crosshair horizontally to the right while holding the SHIFT KEY, or make sure to work in ORTHO mode (button on the bottom of your document window) to make sure that you are creating a straight line.

Now that we have a straight reference line, we can see a problem. The lines within the placed image are not orthogonal to the X Axis within our document.

Rotation Needed

4-rotation needed.JPG

Before we rotate, it would wise to document the North Orientation of the image. We know that the top of the placed image is oriented to north.

From the left main toolbar select the CIRLCE or simply type Circle . Follow the commands from the COMMAND LINE. Make a reasonably scaled circle. To give the circle an orientation type Line and hover your cursor in the center of the circle.

If the CENTER option from your OBJECT SNAPS is selected. The line will snap to the center of the circle. Now, holding SHIFT, or with the ORTHO mode (next to O(bject)Snaps) along bottom row, draw a vertical line upward.

Object Snaps


If the line does not appear straight, this can because other Object Snaps were selected and causing Rhino to automatically search for conditions to snap to. You can avoid this problem one of two ways.

1) Turn of OSNAPS by selecting DISABLE (far right of Object Snap options)

2) Draw the line vertically and beyond the edge of the circle. Trim the line by typing Trim and following the commands from the COMMAND LINE.

Straight North Line




Now we can rotate the image. Type Rotate and select the image and north arrow manually. In most CAD programs (including Rhino), you can select objects in three ways:

1) Drag your cursor over the entire object from LEFT to RIGHT

2) Drag your cursor over any part of an object from RIGHT to LEFT

3) Simply click on the object(s)

After you have selected the two objects, follow the questions / steps within the COMMAND LINE.

1) Select the Center of rotation - In our case select the left end of our horizontal line.

2) Angle or First Reference Point - Select the upper rightmost corner of the block that we are referencing.

3) Second Reference Point - Select the line we previously drew.

Image Rotated

5-rotated.JPG Note: We can double check the accuracy of our rotation by drawing a vertical line from the upper right corner of the block downward and checking for vertical alignment.

To scale the image type Scale and follow the series of commands within the COMMAND LINE.

1) Select objects to scale

2) Origin Point - Select the left end / upper left corner of our referenced block

3) Scale Factor - Select the upper right corner of block along the line that we previously drew.

4) Second Reference Point - Selected the right end of our drawn line.

Rotated & Scaled

6-rotated and scaled.JPG Double check the scale by using the Distance command over the same referenced measurement.

Set up the Layers

Layer organization is key for a good drawing, especially as the work becomes more detailed. Architecture offices are usually very particular about layer titles and maintenance. Check out this website for a listing of typical layers used in a drawing. Notice how many of the layers have the same display color, which organizes the lineweights when the drawing is plotted (for example, all magenta layers are used on detail layers and would probably be given a 0.125 pt line type). For more information on line weights, see this Tool page .

To create new layers, simply select the new layer button in the layer tab of Rhino. You may chose to coordinate the layers with lineweights or object types to help quicken the process when you export the work to Illustrator. Because you are working with an existing drawing, you can probably identify the different lineweight types and organize the layers accordingly.

For our site plan drawing, lets name a new layer "Streets" and make sure to name the layer we have been working within "Base Image". We should lock the "Base Image" as well. This will keep us from altering it for now.

Double click on the "Streets" layer to start drawing.

Tracing Streets

Before we begin to trace the streets from the map, it is best to think about our overall layout. Because of the rotation of our base image, we have an irregularly oriented rectangular shape. It is smart if we define a border to work within.

First, select the RECTANGLE TOOL or simply Type Rectangle . Select the rightmost corner of the placed image and then the leftmost corner (the order is not important).

Slender Rectangle


Now, to SCALE the rectangle type Scale1d and follow the commands from the COMMAND LINE. When prompted to select the "Second Reference Point" select the topmost and the bottommost corners of the placed image.

Scaled Boundary


Because all of our streets are orthogonally aligned we should work on ORTHO mode (select ORTHO from the bottom menu).

Starting with a street of your choice, use the Line command to begin tracing. Draw a straight line along a street edge until it intersects with the bounding box. Now to finish the opposite end of the line, simply type Extend and follow the commands.

Now, to create the opposite side of the street, we need to get a sense of what the width should be. Using the Distance command measure the width of the street that you are drawing. Now, type Offset , select the line you are offsetting, move the cursor to the side that the new offset line should be drawn on, and type in the number of feet (in this case the width) to be offset.

Repeat these steps for the remaining streets, both vertically and horizontally.

Note: It is most efficient to work from open operation to the next rather than carrying out every operation on a single street and then moving to the subsequent street. In other words, follow these steps:

1) Draw one side of all of the vertically oriented streets.

2) Extend them all together under a single Extend command

3) Measure each street's respective width and Offset appropriately

4) Repeat for the horizontally oriented streets

You will probably encounter similarly dimensioned street widths. If they are close then it is probably a safe bet that they are the same width. Offset accordingly.

For the sake of the studio assignment associated with this workflow we will concentrate on the streets within the immediate area of the selected site [all streets passing through the white highlighted area and Jessie St (the first street to the left of Mission)]

Streets Gridded

12-streets gridded.JPG


Now we can trim the street grid into city blocks.

Type Trim and select one of the two horizontal lines that represent a single city street. These are your cutting lines.

Trim - First Step


After hitting ENTER, you will select the lines to be cut. These are the lines inside of the two selected horizontal lines.

Trim - Second Step


Now repeat the process running vertically for every intersection along the selected street. After selecting Trim , select the vertical lines that intersect with the selected street. These are you new cutting lines.

Trim - Third Step


Finally, trim the lines inside of your cutting lines

Trim - Final Step


Note: Remember to be mindful of where streets dead end and trim accordingly. AND PAY ATTENTION TO THE STEPS INDICATED WITHIN YOUR COMMAND LINE.

Creating a Sidewalk Edge

Now, JOIN all touching lines. You can easily do this by selecting all lines and typing Join .

We will now be creating sidewalks. It will be useful to create a new layer. Name it "Sidewalks" and double-click it to begin working within the new layer.

Offset the interior of each block by 6 to 15 feet in order to represent the sidewalk. While sidewalk widths can vary, for this workflow we are relying primarily on using our best judgement. When working in an architectural office on designing a project to be built accuracy would be paramount. Therefore, we would be using city plans, civil engineering plans, or measurements we would take in the field when drawing our site plan.

Sidewalk + Street Layer


Tracing Buildings

Create a NEW LAYER and title it "Buildings". Working within the blocks that we have outlined, begin to trace every individual buidling. Make sure to Join every building after tracing. After joining, within the COMMAND LINE, make sure that each respective building's curves are "joined into one closed curve." This is important for later linework adjustments in Illustrator.

Closed Curves

16-closed curve.JPG

Some buildings can be rather complicated to draw in plan. To make sure that you are being as accurate as possible, use the tools at your disposal:

1 - Use the Distance command frequently in order to make sure that building dimensions are reasonable.

2 - Within the raster image, take note of lot dimensions and shadow lengths. These can provide important clues in determining specific dimensions and spatial relationships.

3 - Use Bing or Google to cross-reference your raster image. Perspective and axon views can provide clarification.

Bing References

15-map.JPG 15-mapbing.JPG

While tracing, remember, many different commands can provide the same results. Explore the following commands:

- Line

- Polyline

- Rectangle

- Trim

- Split

- Offset

- Copy

- Mirror

- Join

- Extend

Things to remember:

- Explore ORTHO mode and OSNAPS. These will prove to play a significant role in both precision & time management.

- Drawing is a form of observation. Inevitably, you will need to adjust what you have previously drawn. For example, sidewalk / street dimensions may need to be changed. If you are working with closed curves, these should be easy adjustments with the help of Scale & Scale1d .

Traced Buildings


Including Cars

After tracing the site it is apparent that parking lots represent a significant portion of the area. To signify the the location and magnitude of parking lots we will include drawings of cars.

From the top menu bar select "File > Import" or simply type Import . Select the Car.3dm file. A small drawing of a single car will appear within the document window.

With the car selected change it to a new layer titled "Cars". You can easily move objects to new layers from the drop down menu within the Properties Panel. Type Properties to open the Properties Panel.

Properties Panel

18-changing layers.JPG

Now, Group the curves of the car and begin to Copy it appropriately throughout the site plan. Scale and Rotate if needed.

After, the cars have been drawn, we are ready to begin the process of bringing our linework into Illustrator.

First, Rotate all of our layers back to orient back to north pointing upward and then deactivate the "Base Image" layer.

Site Plan Linework


Exporting to Illustrator

To bring our linework into a vector based editing program, or in this case Illustrator, type Export . Make sure to select .ai (Illustrator) file format from the drop down menu. Next, a dialog box will appear. Scale your drawing accordingly.

Exporting Dialog Box


Illustrator Adjustments

Open the file in Illustrator and you will notice that all of the layers you had selected have been preserved. The drawing will be located on the artboard similarly as it was located in your Top view.

Change the document layout so that all the linework fits on the artboard. Adjusting the linework should be quick if all the layers are properly organized.

Illustrator Artbord


Experiment with FILL and STROKE.

Final Image Example


Common Problems?

  • I'm having difficulty scaling the drawing.
Check to make sure that your Units are correct - both the unit of measurement as well as the display settings. Note that it is difficult to perfectly scale the drawing - when double checking the distance, the measurement might be off by 1/4'.
  • My file won't open in Illustrator. Why?
Sometimes newly exported files do not read properly right away. Try opening the program (Illustrator) and then open the drawing within Illustrator.
  • Only half my linework exported to Illustrator.
Only the linework selected when using the Export command will be exported to Illustrator. Make sure that you do not have any layers or objects locked in Rhino. Re-select everything and try exporting the artwork again. Layers that have a White display color may seem hidden in Illustrator because of the white art board.
  • I cannot drag the linework onto my artboard in Illustrator.
Make sure that the approximate center of your linework to be exported is positioned at the origin of your Rhino document. You can move all of your linework by selecting it, typing Move , selecting its approximate center, and typing "0,0,0".