Drawing to AutoCAD

ArborShadow can be used to create AutoCAD script files which can then be loaded into any version of AutoCAD for plotting. The scripts can be either the individual shadow, the day extent trace or the larger canopy outline of the tree. When you select the Export Script function you will be asked to define a filename.

The script file consists of a number of drawing entities which use the relative method for co-ordinate placement. All co-ordinates are calculated from the tree centre position so when plotting within AutoCAD we must ensure that the script also starts drawing relative to the same tree centre.

As an example I will plot the two shadow outlines on the following image. I have exported both shadow types and created to files on disk.

I have the original AutoCAD drawing loaded and positioned correctly. I have checked which units are being used and set the preferences accordingly. I also have my script toolbar active. This is a good time to create a new layer so you can keep the shadow data separate and switch able. I have created one below called Shadow_Plot and ensured it is Current. A typical plot produces hundreds of entities which can be a pain to remove or transfer to a layer at a later time.

 

To plot the shadow scripts I must ensure the current plot position is first centred to the centre of the small circle which designates the tree position. This is carried out using the ID command which is built into the custom tool button. So, after selecting the Script plot button on the custom menu I am asked to pick an ID point with the mouse. So I need to use Snap to Circle Centre which is also on my toolbar and then position the mouse cross hair near to the the target tree centre (see below).

 

Click the mouse and the Script load window appears. Its now a simple case of loading the script file which I saved from Arbor-Shadow.

 

 

Once selected the shadow outline is plotted.

I repeat the operation for the true shadow outline.

 

 

The image resembles the Arbor-Shadow screen shot at the start of this page. Obviously some accuracy is lost in the process due to the scaling of a bitmap within Arbor-Shadow. This is one good reason why it is best to use a high resolution bitmap and choose to synchronise over a long distance so that accuracy increases.

As you can see the plot only creates an outline. If you wish to fill (hatch) the shadow then you have two options.

One option is to first plot a single shadow. Then turn off all other layers. Create the Hatch (on a new layer if required). And switch all layers back on.

Or, alternatively, and probably easier is to first plot the shadow away from the site on an empty background. Create the hatch as above and then move the whole shadow plot to the target tree position.