Viewing 3D Models
The interactive 3D Models on this site are stored in Adobe Acrobat (U3D) 3D pdf format. They can only be viewed with Adobe Reader. Most recent browsers, and, increasingly, the latest updates of operating systems as well, have built-in PDF viewers that open pdfs by default. These will not display the 3D pdfs. The most straightforward way to view these files is:
1. Install the free Adobe Reader, if it is not already present.
2. Set Adobe Reader as the default pdf viewer for your operating system.
3. Once Adobe Reader is the default pdf viewer, open a 3D pdf from a blue hyperlink on this site, by right-clicking the hyperlink, then select "Open in New Tab". The pdf will open in Adobe Reader. (Once you have followed this step once, in most cases, simply left-clicking on a blue hyperlink to a 3D pdf will open it).
4. The file will open in Adobe Reader as a blank screen with only a watermark indicating authorship of the file. Follow the yellow security band at the top of the screen over to the right and click the little "Options" drop-down. Give permission to open the file., either once or always Then left-click once in the middle of the screen and the 3D content will appear.
Windows and Mac Desktops and Laptops
On Windows PCs, when the 3D pdf opens and the 3D content is displayed, the Adobe viewer will have the "Spin" navigation mode enabled; Perspective view; and in the "Solid Outline" view mode. You can change any of these initial settings on the 3D Toolbar.
On Macs, from Safari, the model may open showing only a watermark with the credits. Moving the cursor to the bottom middle of the screen will open a dialog box. Clicking the Eye icon will display the model. (Thanks to Kurt Hasselbalch for these instructions.)
Some Mac desktops and laptops may have a pdf viewer other than Adobe Reader set as the default pdf reader. Some Macs may not even have Adobe Reader installed at all. It's easy and quick to download and install it. You need to use Adobe Reader to view these interactive 3D files.
Once you are viewing the model in Adobe Reader, you can spin the model by dragging with the left mouse button depressed; zoom in and out with the mouse wheel or by dragging with <Shift> depressed; and pan by dragging with <Ctrl> depressed. The default "Spin" navigation control seems the most intuitive, but you can also try the "Rotate" and "Fly" controls.
If the model is complex, the left-hand pane will be displayed. Expanding the "Assembly" title will show the various layers. Layers can be turned off and on by unchecking and checking the boxes next to the layer names. A few models have more than one level of layers. When the model opens, all layers will be visible.
The 3D models are set to open to fill the browser window. Most models that open with the layers pane visible on the left also show the Reader toolbar, which allows you to zoom the frame containing the image within the Browser window. Simple models that open without the layers pane visible usually have a pop-up menu near the bottom of the screen that has zooming buttons. The rightmost (Acrobat icon) button on the pop-up menu opens the full toolbar, and the rightmost button on the toolbar returns to the pop-up menu.
Occasionally, the response to the navigation commands (zooming, panning, rotating) will be very slow. If this happens, just click the Back Button to go back to the web page, then open the model again immediately - this will usually speed up the response.
iOS Devices
On the iPhone and iPad, neither the default pdf viewer nor the watered-down version of Adobe Reader for iOS can display interactive 3D models. The business of viewing 3D pdfs on mobile devices has been, unfortunately, something of a moving target. Currently the app "3D PDF Reader" by Tech Soft 3D, works well for this purpose.
Android Devices
TurboViewer is also available from Google for Android mobile devices, but we have not had the opportunity to test 3d pdf viewing on Android.
Where do these models come from?
Magic.
(Actually not.)
It's a Trade Secret.
(Actually not that either.)
It's just a bit of hard work (don't try this at home). The process of creating a 3D model like the ones you can view on this site goes like this (for example, for the models of Herreshoff boats):
1. We enter the frame offsets from a copy of the original Herreshoff Mfg. Co offset book, provided by the MIT Museum, into a particular screen of our in-house computer software BevelGage that was designed specifically to prompt for entry of feet-inches-eighths offsets.
2. BevelGage plots and fairs each frame curve (the offset books give every frame - we don't necessarily need every one to create a model). BevelGage exports each curve as an AutoCAD dxf file.
3. We bring all of the dxf frame curves together in AutoCAD in a single drawing. We also draw the profile and the sheer curve, based on the ends of the frame curves and additional points as needed from the offset book.
4. We bring the AutoCAD drawing into Rhino, then arrange the frame curves, the profile, and the sheer line in plan view in their proper locations in 3D space. We place these guide curves on a frozen layer (you can see them but you can't change or move them).
5. We create a vertical flat NURBS surface using Rhino, then convert it to a T-Spline surface using the T-Splines plug-in for Rhino. We then pull the control points of this surface out in the z-direction until the surface corresponds to the guide curves. Then there's a lot of manual fairing - and this is a lot harder than it sounds. It's much more difficult to fit a fair surface accurately to a pre-defined hull shape than it would be to design a very-similar hull from scratch.
6. Next, we use the Orca 3D marine design plug-in for Rhino to define and display the sections - the station lines, waterlines, and buttocks. Orca will produce a 2D lines drawing from the 3D model, but for the 3D models, we export directly from Rhino.
7. The interactive 3D models on this site are stored in the underutilized Adobe Acrobat 3D pdf file format. We create the 3D pdf files from Rhino using the SimLab 3D pdf Exporter plug-in. The 3D pdf format protects our source material and allows most people with desktop and laptop computers to view and manipulate the 3D models on-line using only the pdf-viewing software that is already installed on virtually all computers.