How To Tell a Story with Automatic View Cycling, Narration & Dynamic Captions
A simple 3D PDF with manual views is very common. When a user is faced with several views they can select each view using the selector menu. Easy enough. But what if you want to tell a story and show your user each view in a sequence or specific order with a beginning, middle and end, and with accompanying narration?
The Hard Way to Tell a Story
In a default PDF conversion, all parts are shown in normal state and views are set to various orientations around the whole model. Part selection and isolation is possible to force a sequential selection, however it requires navigation of the model tree menu and a setting of the rendering modes by hand, which isn’t very user-friendly.
For first-time viewers without such experience, a better way is needed to show a sequence of part views, where the orientation is modified to show a specific part at a time. In this instance, all other parts would appear in a neutral colour, while the selected part would be accompanied by a caption to explain that particular part in more detail.
In this article, we’d like to show you an easier way where the automatic cycling through of each part and stage of the model progression are added without requiring any user actions. If a user makes a 3D action to zoom, rotate, and explore the detail manually, the automatic cycle pauses until the scene is quiet again after a time-out period.
The Easy Way to Tell a Story
This process assumes as a starting point:
- You have a PDF3D ReportGen program installed with valid license
- Samples are installed with supporting tutorial files
- You have access to a non-formatting text editor such as NotePad++, Visual Studio, Emacs, Vi, GEdit, or XMLSpy.
Extending XML with new tags
The standard menus in PDF3D ReportGen offer basic functionality, however there are no menus to perform the actions explained in this guide.
- First, the models and basic settings should be established and exported to the .pdf3dsettings state file.
- Next open this file in an editor
- extend it by adding additional tags
- then reload it into ReportGen then convert.
A completed customised .pdf3dsettings file is provided as a working sample. Once developed the .pdf3dsettings file can be used by the XML Server for automated production and many more XML tag options.
Parts Names, Sizes and Locations
Next, you’ll need to enable 3D mouse probe temporarily, and convert and open the model tree. Write down a list of key model tree part names you want to automate, select them with the probe and note key locations and sizes in X,Y,Z coordinates.
That little annoying less-than (<) symbol
- Cleverly re-write conditional expressions to avoid less-than, double ampersands, or
- Replace < with <
The second is easiest to do, without changing the logic of the code, but is not so good for humans reading it. The first is best if you want the code to look the same and work the same both in and out of XML context.
Extending XML Tags
Add Custom Views
Views may be either those created automatically as DefaultViews (CAD, Geospatial, Anatomical schemes), or those which arrive from an external source such as one of the file loading or plug-in interfaces which may contain view information, or they can be added here by hand in XML.
First, you’ll need to disable all except our new custom ones with:
Next, several new views area added with specific title names and orientations. Each view can be isometric (orthographic) or perspective, and the camera location is relative to the bounding box extend of the model (see below):
<Camera x=”-0.7″ y=”-0.1″ z=”-0.7″/>
<CameraUp x=”0″ y=”1″ z=”0″/>
<Camera x=”0.2″ y=”-0.5″ z=”0″/>
<CameraUp x=”0″ y=”1″ z=”0″/>
<Camera x=”0.7″ y=”0″ z=”0″/>
<CameraUp x=”0″ y=”1” z=”0″/>
Add Text Forms
You’ll then be able to add some static labels and dynamic text-field areas for the view name and the caption text. The first one is for view name (single line):
<DrawText value=”View” left=”700″ bottom=”550″/>
The second is for multi-line dynamic caption text box. These are much simplified for purposes of this article (see tutorial files for all the typical style attributes):
<DrawText value=”Description” left=”700″ bottom=”500″/>
<WidgetText isMultiLine=”true” name=”WidgetTextField-002″/>
Start by adding the automatic timing period parameters:
var interval = 5; // time interval between views
var patience = 10; // timeout after any mouse interaction stops
Now is the time to add the journey to define the view order and add narration prose. This is defined by a simple table. Paying attention to the names of views and the model tree name homework, add a small table, as in this example which shows 3 columns and 6 rows:
// part name, view name, caption description table
var caption_content = [
[“nothing”, “Overview”, “A-type Suspension, Structural Overview in 3D PDF, Part Descriptions”],
[“3_Instance1_Resource”, “Spring”, “Compression Coil Spring over Shock, Stores and Releases Energy”],
[“2_Instance2_Resource”, “Shock”, “Shock Absorber Unit, Hydraulic Damper using Oil-Piston Improves Handling”],
[“1_Instance2_Resource”, “SteeringLink”, “Control-arm for Azimuth Steering of Wheel Mount with inline damper”],
[“7_Resource”, “Wishbone”, “A-type support structure for Lateral strength, with mirror part below”],
[“nothing”, “Next”, “Next view description goes here”]
A completed sample implementation is included in
This general method can be extended to use view-dependent visibility (hiding some objects on particular views, adding hyperlinks to additional areas of the document or external URLs, adding PMI or custom annotations into the 3D scene.
And there you have it. We’d love to hear how easy you found it to add the order and narration. Get in touch to tell us how you got on.