It all becomes transparent…..

6 January , 2008

Happy New Year!!! So here is my first post of 2008 – I did intend to post a few times over the festive period but got caught up in mince pies and sherry……But better late than never.

When AutoCAD Map 2007 was released with its new FDO (Feature Data Object) engine I found the transparency functionality and thought – ‘excellent see-through data!’. There was a catch however, although it’s great for polygons, I have never been able to make raster data transparent – until now!!

Through some useful posts from the community on the AutoCAD Map discussion forum; and through some trial error, I can now make my raster images transparent. This is how to do it……..

Step 1 – Add the raster image to the DWG through FDO

Open the ‘Data Connect’ menu found on the ‘Display Manager’. Once in the editor, select ‘Add Raster Image or Surface Connection’, navigate to the file you wish to connect to and then tick the box and hit ‘Add to Map’.This will add your raster image connection to your DWG.

Before Insertion

 

After insertion

As you can see from the screen captures above, the image displays in the correct location as AutoCAD Map understands its associated ‘World File’. However it has been placed in front of the stadium design CAD data, hiding it.

Using the Display Manager I am able to manage the draw order of my data in Model Space and could force the image behind the CAD data. In future posts I will explain the tips for doing this. In this example however I want to make the image transparent.

Step 2 – Save a ‘Layer file’ for the image

A Layer file is an XML based file that you can export from AutoCAD Map for any FDO connection you have made in the Display Manager. Within the file it will save all the styling information and it also records the location of the data source e.g. Location on disk of the Raster Image file. Once the file has been created you can add saved Layer files into any AutoCAD Map DWG to re-use them – making it very easy to connect and style the data.

To create a Layer file for the raster image that has been connected simply right mouse click the layer on the Display Manager and select ‘Save Layer’

It will prompt you for a name and location to save the Layer file. 

Step 3 – Edit the Layer file to enable the transparency.

To make the image transparent you need to add a extra line to the Layer file. In Windows Explorer, navigate to the Layer file that has just been saved and open it in Notepad.

This is the data contained within a Layer file.

To add the transparency setting, find the line that defines the ‘FeatureName’. Its usually about 22 lines down in the file. 

It looks like this: 

FeatureName: <FeatureName>rasters:MyRasterImage</FeatureName>

Underneath this section on a new line add the following…..

<Opacity>0.6</Opacity>

0.5 being the degree of transparency – 0.1 is very transparent, 0.9 is not very transparent.

This is how your file should look:

Before Edit

  

After Edit

Once you are happy, save the notepad file.

Step 4 – Add the Layer file to AutoCAD Map DWG.

Now you have added the transparency in the Layer file you can add the Layer file to your DWG.

Turn off any other Raster Imagery in your DWG. From the Data button on the Display Manager select ‘Load Layer’ and point to your Layer file.

This will add the Raster Image to the Display Manager in the same way as doing a Data Connect would do, except this time the transparency should be activated.

You now can see the Stadium CAD data below the image.

Check back for more soon!

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The power of the Display Manager – Part I

14 December , 2007

For today’s post I want to go back to basics and highlight the unsung hero of AutoCAD Map – The Display Manager.

When the AutoCAD Map application opens the Display Manager will appear automatically on either the right or left hand side of the GUI. At first sight its use may seem slightly ambiguous, with a lot of white space and just a few buttons. DO NOT SWITCH IT OFF! All too often I train users that simply turn the Display Manager off, and in doing this, lose access to huge amounts of functionality.

In short, the Display Manager enables you to manage how data is displayed in the model space and how that data is styled. It doesn’t replace the AutoCAD Layer Control, it just compliments it.

The Display Manager is a bit ‘Dr Jekyll and Mr Hyde’ depending on the type of data you are managing…..It will provide different functions and options dependant on where your data resides. When managing data held within the DWG file, i.e. CAD entities, it provides one set of functions for styling and querying. When managing data accessed through the FDO (Feature Data Objects) connection mechanism it provides a whole range of other functions, including connection to the data, styling, editing and a quite a bit more. A major advantage of the Display Manager is its ability to manage all of this data, regardless of its source and produce a map for you to use in model or paper space.

In this post I will highlight some of the cool things you can do with the Display Manager when managing data held within the DWG.

Cool Thing no. 1 – Managing the display of your CAD layers

You can use the Display Manager as a time save for turning layers, and groups of layers, on and off. All you have to do is pick which layers you would like to add to the display manager…..

 LayerAdd

This will open the ‘Select Layers’ editor which lists all the layers within the DWG.

Each layer you tick is added to the Display Manager. Once on the Display Manager you can control the visibility of the layers within your Map very easily by simply switching the data on and off using the tick box.  

Another top tip is to group the layers together by using the ‘Group Selection’ option. This way you can turn a number of layers on and off at the same time. Any layers that aren’t added to the display manager can be turned on and off all together by toggling the ‘Map Base’ option, which automatically groups all other DWG layers.

Managing your layers through the Display Manager in this way will allow you very powerful control over what you see in your Model or Paper space. It also provides a effective way of managing draw order – more on this in a future post!!

Cool thing no. 2 – Managing Styles on your layers 

Once you have added your DWG layers to the Display Manager you then have a range of functions you can perform on that data. One such function is ‘Add Style’. The different styles available can be found by selecting the layer in the Display Manager and right mouse clicking.

Styles offer you the ability to apply hatching, annotation, symbols and themes to the data. You can style based on your standard CAD properties such as .Area or you can style based on intelligent Object Data (data attributes) that can be stored against each entity. For example you may be storing an attribute on a set of polygons recording the ‘Use’ of a building – The resulting Theme may look like this…

Cool thing no. 3 – Querying the data

Any CAD entity within the current DWG or stored within an external DWG can be “queried”. The results of the query are added to the Display Manager as a single display layer. 

The query can be based on a range of conditions such as a location – e.g. All entities within a rectangle, or it can be based on a property or data condition. It is possible to build up very powerful query by using a combination of different conditions.

Queries can be saved reused over and over. As long as you know your data, the query tool can be extremely powerful.

Continuing with the ‘Buildings’ example, the following query has produced a Display Manager layer containing all polygons in which the CAD property .Area is greater than 2000 msq.

So if the first thing you do when you open AutoCAD Map is to turn off the Display Manager – don’t. Have a play with some of your data and some of the functions and I bet you will like what you see.