The 3D block provides an interactive view of a 3D object. Such objects can be made either using a 3D software, or scanned using a mobile phone or a specialized 3D scanner. Many museums and other organizations are using 3D scanning techniques to visualize and digitally preserve artifacts. Being able to look at an object from all angles, almost as if you were holding it in your hand, is a great way to present such content to your visitors.
You can rotate and zoom in on the object by natural gestures, such as swiping and pinching on a touch screen. Buttons can be added to the object, acting as hot-spots to navigate to other objects or specialized views, play related content, or interact with the environment in any other way supported by Blocks.
Watch this video for a brief overview.
The 3D block requires Blocks 5 or later. Furthermore, this is a premium block type, which is an optional add-on to your Blocks license. Display spots will show a placeholder instead of the 3D object image if this option isn't included in your license.
To try out this on your own, start with the general setup guide to recreate this application using this Blocks root.
- Add a separate browser window (or a PIXILAB Player) pointed to your Blocks server.
- Assign it to the display spot shown in the list.
- The 3D block appears on the display spot.
- Swipe (or drag with the mouse) to navigate.
- Click the buttons to trigger actions.
Obtaining 3D Models
The 3D Block requires a GLB file as its model. This has become a web standard 3D file format, popularized by websites such as Sketchfab, the Smithsonian Museum and many others. While the Smithsonian provide its models in GLB format as standard, Sketchfab instead supports the closely related GLTF format. Both GLTF and GLB are part of the same standard, with GLB being self-contained and more compact, making it suitable for efficient distribution and display purposes.
If your model isn't in the GLB format, you can often convert it quite easily using any of the following methods:
- A GLTF file collection can be directly converted to a single GLB file using a number of on-line converters. Just google for gltf glb convert.
- Use a 3D application such as Blender to import the GLTF files then export it as GLB.
- Since Blender can import a wide variety of 3D file formats, it can often be used to convert those too, although this may require a bit more manual adjustments.
If you have a Sketchfab account, you can also use Sketchfab to convert other 3D file formats since Sketchfab can import a variety of common 3D file formats. Once imported into Sketchfab, download it as a GLTF and proceed as described above.
Using a 3D Scanner
A physical object can be scanned to produce a 3D file. Making a good 3D scan is often a very time consuming process, requiring a skilled operator for best results. Numerous professional grade 3d scanner options exist, both based on regular camera images and other technologies such as laser, lidar and structured light. There are also companies specialized in 3D scanning, as well as on-line services that can help.
Finally, there's a rather new breed of 3D scanner apps, such as this one, taking advantage of the combination of camera and lidar scanners built into some modern phones and tablet devices, such as Apple iPhone 12 models. Search for 3d lidar scan to find several such apps. Note that the results obtained by such methods are often far from what can be obtained by a professional grade scanner, but can be used as a quick test.
Reducing 3D Model Complexity
Some 3D models may be too complex to display in Blocks with adequate performance. A very large model takes longer to load, requires more memory during playback and interaction may be sluggish. This is often the case for models obtained using a 3D scanner. To use such a model in Blocks, you may need to reduce its complexity:
- Decimate the number of triangles used in the model file to express its geometry.
- Reduce the resolution of the textures applied to the model, and save them using the JPEG format.
This is a manual and often time consuming process, that requires specialized tools and skills. A general-purpose 3D program, such as Blender mentioned above, can be used as part of this process. Look for terms such as "simplification" or "decimate" that can be applied to complex meshes. There are also a few free, specialized programs such as Meshlab and Instant Meshes, as well as several commercial alternatives.
Here are a few more resources related to producing and using 3D content, especially for cultural heritage purposes.