3D Scanning¶
Key Concept¶
3D scanning is a design mechanism that allows you to read, generate, and digitize 3D design from real-world physical object.
3D Scanning Techniques¶
There are many techniques to do 3D scanning, but here are the most popular ones for product design and fabrication:
- Laser-scanning: basically scanning the object by shooting laser beams to the object’s surface so that the device can calculate the depth and proximity of the surface’s texture. Most 3D scanner devices utilize this method.
- Photogrammetry : the technique of making accurate measurements from photographs and using optics’ principles, the camera’s interior structure, and its orientation to reconstruct dimensions and positions of objects from overlapping images (Campbell and Wynne, 2011).
- Axis Probing: I remember my colleague, Eka, once did a 3D scanning by using the Modella Milling Machine, and basically, the process is just like doing height-mapping / z-probing
Choosing 3D Scanning Technique and Software for Mac Users¶
My consideration is to find the software that:
- cloud-based
- faster processing time
- less to no installation
- free / open source if possible
Polycam
After researching and (almost) desperate, I found Polycam as the one that suits my condition the most.
- It’s cloud based! So you can either upload your capturing data through web or from your phone directly!
- It has amazing UI!
- Suitable for environment or architectural rendering
- Many people have used it as you can see a lot of people upload their works in the explore gallery, so it seems very trusted!
- The only downfall is that it’s not free…
But anyway, I decided to try this as nothing works with other softwares that I try. I’m utilising my 7-day free trial access for this assignment.
Photogrammetry with Polycam¶
For this week’s assignment, I’m going to scan this turtle mini sculpture object in our house.
Here’s the general workflow to do photogrammetric 3D scanning with Polycam:
1. Capturing Object¶
First of all, you need to have a Polycam account. Once you signed in, just go to the + sign which says ‘Capture’. It will then direct you to this page. You have option to take videos, and the polycam will take the pictures automatically, or manually by capturing images one by one by yourself.
💡 Tips: how to take good capture? The photogrammetry works by connecting multiple info from your image data, so try to capture from as many angles as possible, with good lighting, but not too intense. If your object is reflective or shiny, try to diffuse the light because it’s difficult to read shiny reflective object.
Once you are done, you can upload the captured images. As you can see, at this stage you can already choose the processing mode and details of quality that you’re looking for. I have tested the Medium, Full, and Raw quality, for this type of 3D scanning, Medium quality is already good enough.
2. Processing Data¶
Next, once we’ve decided on the quality detail, we can go ahead to process the image data into digital 3d design model. And just wait for the result.
3. Scanning Result¶
4. Editing¶
Next, polycam comes with ability to do basic edits and cleanup. For example here, I cropped the outeredges
Aside from accessing Polycam in the mobile version, you can also go to the web version. There is a mesh inspector feature where you can view and evaluate in the’mesh’ mode and also ‘shaded without texture’ mode.
Default view mode:
Mesh-view mode:
Shaded mode:
5. Export¶
In Polycam, you have a wide range of export options. To maintain the image texture, you can export it in GFTL (.gbl) format.