Transparent images in ArchiCAD

Written by Balázs Biacs

The 20th Anniversary Edition Version [R3/v3] of ArchiCAD 7.0 introduced a new additional feature, the Transparent Picture.

This feature lets you use even simple images with a white background as transparent pictures. This means that the images do not have to have an alpha channel mask - their white pixels will not hide what's 'behind' them.

Let's see how to use this new easy-to-use function through an example:

Let's insert an image of a pine tree into an elevation of a residential house:

Let's try to insert it using ArchiCAD's Figure Tool.
First we have to resize this picture to the correct scale. In this example a width of 5.1 meters [approx. 15 feet] seems to be appropriate.

To make the picture transparent, tick the 'Transparent' checkbox as shown in the screenshot below.

After placing it into our elevation, we need to select this figure and bring it to the front using the 'Bring to Front' command from the Tools menu.

However, there seems to be a problem: even though the placed picture has the 'Transparent' checkbox checked, it still blocks out the lines of the elevation:

Let's check to see if the background of the picture is a true white:

Open the file in an image editor software and use the Dropper Tool to check the RGB values of the background:

There it is: the background has RGB values of 248,248,248 (a very light shade of grey) instead of 255,255,255 (White). We can remedy this by using 'Flood Fill' to make the background a pure white fill, and then saving the image under a different name.

Important:
We recommend to use PNG or TIFF images - these have a fixed color table which JPEGs have not. JPEGs sometimes get their colors shifted which results in the loss of transparency in the floor plan.

Now delete the original figure in the elevation, and place the one with the true white background.
The elevation should now look like this: (the white pixels became transparent)

Note: don't forget to bring this picture to the front using the Tools/Bring to Front command!

Printing - Plotting Transparent Pictures

Plotting:

Plotting images from PlotMaker with white background works the same way as in previous versions (images were always plotted transparent). The addition in 7.0 R3/v3 is that now you can plot the images as opaque images meaning the images can now hide out what's 'behind' them.

Note: to avoid possible confusion in PlotMaker select to Show Pictures 'As Arranged' in the Options/Display Options dialog.

Printing:

Generally there's nothing special about printing transparent images, however, here are few hints if you happen to experience problems:

• Mac OS X:
  Sometimes the image happens to print non-transparent, meaning the background still hides out everything that's behind it. In this case try downloading a more recent printer driver from the printer manufacturer's website.
  
• Windows:
  Sometimes the image looks OK on screen but prints badly. If updating the printer driver does not help, we recommend you try the following:
  1. Start 'Regedit' (Start Menu/Run/ type in 'regedit' and hit 'Enter')
  2. Navigate to the key:
     'HKEY_CURRENT_USERSoftwareGraphisoftArchiCADArchiCAD 7.0 USADriver Error PatchBad TransparentBlt on Printer'
     and change its value from '0' to '1'.

     

     Note: the key name may vary depending on your localized version of ArchiCAD.

     This setting is meant to be used with the faulty printer drivers only. Use it only with problematic printers, or you may experience problems with the previously non-faulty printers.

Page last updated: Thursday, June 10, 2004