Friday, 31 October 2008

Version-sniffing for inline PDF files

The inline object below contains a PDF file with a 3D interactive model. Because 3D only works in Adobe Reader 8.5 or above, the PDF uses two filtering stages to ensure the 3D element is only displayed when the correct plugin is available. If you have Adobe Reader 9 (or Acrobat 9) then you will see the activated 3D model open below, after a second or two delay.

The first thing we do is insert the PDF using the 'Stirfry' method - a standards-compliant bit of HTML code which works in the main browsers, but ensures that if the user has no PDF viewer plugin, something else appears (in this case the 'get Adobe Reader' image and hotlink:

<object type="application/pdf"
data="" width="320"
<a href="" title="Get Adobe Reader">
<img border="0"
width="158" height="39" /></a>

If the PDF loads, then we use a single line of Javascript inside the PDF itself to handle versioning (we can't access the version number for Adobe Reader directly in a web browser). The PDF has two pages - page 1 is a "you must upgrade" message, and page 2 contains the actual 3D object, so all the Javascript does is move to page 2 if the viewer version is greater than 8. The Document Javascript therefore says:

if (app.viewerVersion >8) this.pageNum++;

You can download the above PDF directly from this link (right-click and Save As), if you want to poke about inside it.

Saturday, 18 October 2008

Horizontal Matthew Walker knot and cowstails

Following a suggestion by the great tyer of string Mr 'Paddy' Morris, we've recently looked at a new, and intensely obscure, knot for making up the harness-end loops on a set of cowstails. The 'horizontal Matthew Walker knot' has, as far as we know, never been used for anything even remotely related to climbing and rope access, and instead has been the knot of choice for salt-encrusted sea-dogs wishing to fashion rope ladders and impress The Ladies. It appears in Ashley (#800) but not a lot since then, and that's a shame.

It turns out that the HMWK is rather a good choice (compared to the usual figure-8 loop knot) and is equally strong, well-behaved even under expansion, but an utter beast of a knot to learn. If there is one knot that you won't be able to get right twice in a row, it's this one - but if you can, it's a damn good knot. It looks nice too!

You can download our report from the link below, which includes test data and background info. It's a 4.8MB Adobe PDF with embedded videos, so you'll need to have Adobe Reader 9, or Acrobat 9, installed in order to open it.

Wednesday, 8 October 2008

P3DF USAR Timber Shoring now available

We're pleased to announce that our first P3DF document package is now available from our website. Covering timber shoring systems for Urban Search and Rescue, the P3DF system uses the latest interactive 3D features of Adobe Reader 9 to deliver a unique and captivating learning experience.

The package contains every standard timber shore pattern, from simple rakers to complex column and sloped-floor systems, and is suitable for use by anyone trained under the US FEMA/USACE/TEEX systems or the UK New Dimensions program.

Single-seat licences are available right now for instant purchase and download - group and academy licences are available on request for those wishing to circulate the documents amongst their employees or students, including the option to add your own logo and styling.

Head over to our website for a free sample!