30 days of 3D Scan

Starting 2021, I came across the trend #1ScanADay on twitter started by Alban denoyel, Ceo of Sketchfab, based on doing 1 scan a day (obviously) and uploading the 3D Scan to Sketchfab.

So I decided to document all my learnings regarding 3D scanning with my Iphone 12 Lidar capabilities and validate an hypothesis:

Soon, I discovered that there were a variety of apps to try with different functionalities and I kept learning about new ones each day. Different apps made updates during the challenge so the capabilities improved over time while other apps restricted their free capabilities to share.

So here you have my insights after trying most of them.

What I learned about 3D Scanning

Across the challenge I thought that some of my scans were awful. But we should learn from our mistakes and keep improving. How could I make beautiful creations as the rest of the people in the challenge were posting? Maybe I was not using the correct app?

Here you have some tips I learned and recommendations from other users:

  • Size: It is not recommended to scan things that are smaller than a shoebox. Also, with really big things you won’t be able to cover all the angles.
  • Technique: go slow while you are scanning, go around the object (remember to cover the top too) and don’t go over again the same area.
  • Light: this will also affect the look of your 3D scan. If you are going to scan objects, try to do it with daylight and with homogeneus light (better if it is a cloudy day). But you can also play with shadows and lights for more artistic results.
  • Don’t try transparent or shiny things: This will make the scan imprecise at best or it will be filled with holes at worst. Also shiny surfaces from a car are tricky to scan.
  • Hard edges and dark surfaces are dificult too to scan. I spent a almost an hour trying to scan the ear of my Pichu (which are supposed to be pointy):
Captured with 3dScannerApp

Also, in this scan you can see the difference of detail on the red guitar vs the black guitar:

Guitar wall captured with Scaniverse
  • Soft rounded things are easier. While I have had a lot of trouble with smaller objects and dark surfaces, this Armchair took me less than 10 seconds with 3dscannerapp. The texture is super smooth and the mesh almost has no holes.
  • Depth Range: The frame of the capture sequence. The max range of 5m is set by the range of the LiDAR sensor and in some apps you can also modify the depth range to limit your capture. But don’t try to scan something very far away.
  • Mesh: collection of vertices, edges and faces that defines the shape of an object. Some apps will apply simplication to the mesh, reducing the polygon count. This could make your 3d model vary between a lower-poly model and a highly-detailed one.
  • Point clouds: different apps base their scan either on point clouds or mesh and this will affect the final look of your scan. You can export the .ply file and edit/trim the cloud points on blender/meshlab.
  • Try to change the settings of the app you are using: For example, in 3dscannerapp you can change the High Res setttings like resolution, masking or range. You can set whether you are scanning an object or a person for better scan results.
  • Texturization: responsible for models being colorful and interesting instead of blank and boring. This will add the color to your 3d object and its quality can vary too.
  • Trimming: some of these apps allow free trimming of your scan and some don’t. To improve the quality of your scan and have a more clean 3D model, you can export your model to you computer, open it on Blender, Meshlab or Meshmixer and cropped the parts you don’t want. See the difference of my donut scan before and after trimming it:
Donut scan captured with Trnio
  • Take into account the size of your scan when you export it. My street art scan was 121,3 MB and I could not uploaded directly to Sketchfab. Luckly, Sitescape have a userguide on how to edit the scans later.

So I used MeshLab to adjust it the number of points and reduce it to 1,000,000 to meet the target max size. You can find more info on: https://www.sitescape.ai/user-guide

  • Export format: In some apps, the free functionalities would only allow me to share my scan in usdz format. So I had to export it to my Mac, open it on Xcode and then export it to a supported Sketchfab format (usually in .dae). So, try to use the embeded functionality and export directly to Sketchfab.
  • And lastly, iterate with the settings on @Sketchfab. The editor can turn a poor scan into an ok scan. Try changing your point size.

What app should I use?

Depends on what you are trying to scan. I have tried different apps to see if an specific app might be better for it. This are my preferences:

  • Object Scanning: My prefered free apps are Scaniverse and 3DScannerApp. You can find other apps like Polycam or Qlone as well as point cloud based apps like EveryPoint or SiteScape for a different artistic result. But for more quality results, for a few euros/dollars you can make really detailed models with Trnio app.
  • Mural Scanning: Scaniverse and Polycam make great Mural Scans. And specially Polycam has invested a bit of work into enabling very large scans.
  • Spaces/Scenes Scanning: I love the results with point clouds apps like EveryPoint and SiteScape. Also great to play with the light. For example, this nighttime playground scan:
Captured with EveryPoint
  • Face Scanning: ScandyPro is the prefered app for the moment. Also tried Capture, but this last one did not allow to export the textures.
  • 3D Video: I tested the Record3D app and the results are super cool. With the premium version you also have RGBD Video Streaming which can be the future for holographic remote meetings. The downsize is that for most recordings, the size of the video was too big to upload to Sketchfab, specially if you are using the Lidar scanner at 60FPS. But you can make super cool hologram videos with the unity demo:
  • Room Scanning: you can find Canvas, Matterport and RoomScanLidar for this specific use, but other apps previously mentioned like Polycam, Scaniverse, SiteScape and EveryPoint make great results.

With all of this continuous testing, here you have my complete Lidar Scan Challenge Collection on Sketchfab. You can see the different quality/artistic results depending on the app used:

Be inspired by the community

Through the past month I have learned a lot from the community on twitter and I encourage you to check some of their creations. I would often go into the Sketchfab library, check what other people are scanning, what are they using for it and their results.

These are some of the creations I liked the most:

My main conclusion is …

You can make profesional 3d models only with your phone. You will probably have to make some modifications to your 3D scan with the app free functionalities or after exporting it, but if you are not required to use high-detailed models, this can be enough.

With the latest iphone capabilities, you don’t need an equipment of 500€ anymore. And in the past months, Sketchfab has become a great library for volumetric scans and it looks awesome.

Also, mid-challenge I saw some users exporting their Lidar scans to unity and WebXR environments and this opens a whole lot of different opportunities. This has the potential to create virtual content that really merges the real & virtual world.

I also got more curious about 3D Design so I will continue my 3D journey and start tweaking with blender and 3D modeling.

What other things do you recommend to improve the quality of 3D scans?

For more recommendations, you can also check the 3d scanning with the iphone lidar post by alban.

Hope that this post was helpful for you.

I would love to hear your feedback. Follow me on twitter at @patritevi and let me know you comments!

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Exploring the extended reality

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