Software for drawing 3D models is nothing new: such tools are readily available and range from prohibitively expensive to free. Your first steps in 3D design will require a considerable investment of time. Even experienced designers will acknowledge that there’s a learning curve associated with the extra dimension – not to mention a greater demand on your PC’s processor.
How to print 3D models
You don’t have to start with a blank canvas and a digital illustration package, though. You could instead create a computer model of an object that exists in the real world. You can take a series of photos of that object, captured from all possible angles, then use sophisticated software to stitch them together and create a 3D virtual model.
Suitable stitching software is available as a free online service, which also relieves your PC’s processor of the gruelling number-crunching. That’s just as well, since the pattern recognition involved could keep your PC occupied for many an hour.
You can edit your model as necessary, and spin it around onscreen for viewing from any angle. Such models are commonly used by online stores and virtual museums – they could enhance your website, too.
The basic method we explain over the following pages is just the start for 3D modelling. If you’re prepared to invest a modest amount of cash, you can use 3D printing technology to turn a virtual object into a physical item.
3D printers are rather expensive, so you’re likely to be better off instead submitting your virtual model to a 3D printing bureau. We’ve chosen the Sculpteo service, which offers reasonable prices and a six-day turnaround.
In a world in which just about everything has gone virtual, using your PC to create a real-world object is a refreshing idea.
Create and print 3D models from photos
Step 1. Take a sequence of photos of your object from all possible angles, including the top – 40 to 50 is a good number, although too many is better than too few. Ensure that there’s plenty of overlap between adjacent shots.
The automated process by which Photofly builds a 3D model requires the software to recognise the parts within each photograph that correspond to the same part of a real-world object. This requirement for sophisticated pattern recognition places some constraints on what can be photographed and how it should be captured.
• Make sure you photograph something that won’t move
• Ensure the lighting doesn’t change significantly between shots – changing shadows will cause problems
• Don’t zoom in or out or change the distance to the object unduly from one shot to another, since this could alter the perspective
• Avoid transparent or shiny objects and refrain from using the flash – this, too, might cause the object’s appearance to change as you move around it
• Bear in mind that the object or scene needs to have identifiable features or texture. Sculpteo warns that photographing the back of someone’s head can often cause problems because one area of hair looks much like any other
We created a model of a modest-sized object in our walkthrough. Photofly can also be used to model large objects such as buildings. In addition to creating a 3D model of the outside of a building, it’s possible to work with a set of photos of the inside of a room – although, in this case, creating a solid 3D-printed object wouldn’t be possible. You can also work with people, but remember that you’ll have to ask them to adopt a stiff Victorian-like pose while you capture the sequence of photographs – any movement and your subject will ruin the effect.
Step 2. Download your photos and have a good look at the sequence of shots onscreen. Make sure they’re all in focus and correctly exposed, that you haven’t accidentally cropped your subject and that the sequence covers all angles of the object with plenty of overlap. If necessary, retake some photographs.
Step 3. Register to use Photofly, then download and install the Photo Scene Editor. Launch the program and click ‘Create a new Photo Scene’. Select all your photos in the ‘Select Photos’ dialog box (hold down Ctrl as you click the mouse to select multiple images), then choose Open.
Step 4. Click ‘Compute Photo Scene’, then choose whether you want to wait or be notified by email when your 3D object is complete. We found that the process took around a quarter of an hour, and preferred to opt for email notification. The following instructions assume that you also chose this option.
Step 5. Your photos will be uploaded to Photofly, which will begin constructing your 3D object. This involves a large amount of pattern matching, so it may take some time to complete. Once you receive the email message, click the link within the message body and save the Photo Scene data file to disk. Now open this file.
Step 6. A 3D model appears in the Photo Scene Editor as a polygon mesh superimposed on a photo-realistic texture. A dialog box informs you that you’re viewing a draft-quality mesh. You’ll see thumbnails of your photos at the bottom. The position from which each shot was taken is shown as a camera icon.