3D Scanning and Photogrammetry Explained

With most of the world staying safe at home for the foreseeable future, retailers of all kinds are grappling with a new normal. One central tenet is that, for now, e-Commerce has replaced in-person shopping scenarios.

Given this new reality, it’s more important than ever for retailers to create online shopping experiences that mimic what happens in stores. One key element of doing that is adding 3D digital twins of their products.

By more closely mirroring what shoppers experience in person, 3D images can boost consumer engagement, increase sales, and decrease returns. But how do you go about creating a 3D version of your existing product?

In this post we’ll explore 3D scanning and photogrammetry, the two main ways to capture real world objects and create 3D digital models that can be used in Augmented Reality (AR), Virtual Reality (VR), 3D web viewers, and more.

What is 3D scanning?

3D scanning is the process of analyzing a real-world object to best capture its shape and appearance. The data collected by the 3D scan is used to construct digital 3D models or “digital twins” of real world objects.

There are several types of 3D scanners, each with its own limitations, advantages, and costs. The two most common types are laser and structured light scanners. Both scanning techniques provide extremely accurate dimensions and can be used to reverse engineer parts and create CAD data for manufacturing.

1. Laser scanner

As its name suggests, laser 3D scanning uses a laser to map the surface of an object’s geometry. A digital 3D model is then made from this data. This is accomplished be shooting out laser beams that are reflected into a sensor which then accurately calculate the distance between the sensor and the object.

Pros: Laser scanning is extremely accurate and you can find them at reasonable costs.

Cons: Laser scanning is highly dependent on the type of surface and does not do well with very shiny or transparent. They are also better at close range and have a hard time at a far distance.

2. Structured light scanner

Structured light 3D scanning consists of an LCD projector and at least two cameras to map the geometry of an object. The object must be rotated or the scanners can be moved around the object to capture all sides. With this method, tracking stickers are used so the software knows how to align the data to create the final 3D model.

Pros: This technology can scan large areas very quickly. They are also very accurate

Cons: Structed light scanners are very sensitive to light. Scanning an object outside this way is almost impossible. They are also better at close range and have a hard time at a far distance.

3. Time-of-Flight Scanners:

Another type of laser scanner uses time-of-flight technology (ToF). The scanner works by sending out laser beams and then measures the time it takes for the beams to bounce back to approximate the distance from the laser to the object. Doing this around the entire object allows the software to recreate a crude 3D model representation.

Pros: These scanners are good a far distance so if you want to scan a building this is a great choice.

Cons: Not as accurate as laser scanners or structured light scanners.

Many phones today have this type of time-of-flight (ToF) technology, however the new iPad Pro 2020 and iPHone 12 Pro have LiDAR scanners which are much better. LiDAR shoots out multiple lasers at once. This provides a lot more information and enables users to shoot from a farther distance (up to five meters). The technology is also better with object occlusion – understanding when one object is behind another object. LiDAR is actually not new. It has been around since the 1960s, but it is finally getting cheap enough and small enough to incorporate in consumer devices like the iPhone 12.

Below is an example of a LiDAR using the new iPhone 12:

As you can see, scanning objects with LiDAR is still crude and is not ideal for ecommerce products yet. This type of scanner is best used for room scale games. It also can be used to accurately place objects, like furniture, in a room. For this reason, it is great for testing out if a piece of furniture fits in you living room or to understand how big a purse really is. This type of AR has proven to increase buyer confidance and lead to more sales. However, to create an accurate digital twin of the product in the first place, we recommend photogrammetry.

What is photogrammetry?

Photogrammetry is the process of taking many photographs of an object from a variety of angels and stitching them together to create a 3D model. A standard digital camera can be used with specific software that detects overlapping patterns to build up a 3D reconstruction of the photographed object.

By comparing pixel colors and defining anchor points, photogrammetry software evaluates and creates 3D models of a vast variety of objects.

The pros and cons of photogrammetry

A benefit of photogrammetry is that it provides more realistic 3D models because the photographs translate to great materials and textures. This allows you to create accurate digital twins.

This technology also is not as expensive as 3D scanners. To digitally replicate objects using photogrammetry, all you need is a camera and a room which has enough light to film in. If the object is human or animal, a multi-camera system may be required in a studio.

Photogrammetry is also good at a variety of size objects. Whether you are trying to capture a small ring or an entire building, both are possible.

One downside to photogrammetry is that it’s difficult to capture parts that have a smooth, flat, and/or solid-colored surface as these objects have no visual pattern to detect. To remedy this powder can be used to add texture to the smooth or shiny surfaces. However, if you are not allowed to distort the surface of the object a 3D scanner is a better alternative.

Conclusion

Photogrammetry and 3D scanning are efficient technologies boasting unique—and advantageous—ways to capture real world objects and create 3D models for ecommerce and more. Overall, when choosing between these technologies, it’s most important that you first consider the types of objects you plan to scan.

Whether you are using a 3D scanner or photogrammetry, it’s important to note that your final result will be a very large 3D file. This will require optimization and conversion to be used on web, AR, or VR. Luckily, VNTANA’s patented algorithms completely automate this process so you can upload an .STL or .OBJ scan and instantly share a 3D web version with built in AR.

No matter what technology you choose, VNTANA can help with your 3D scanning and photogrammetry needs through our 3D scanning partner network. Schedule a demo or contact us by phone or email today.