Using liquid to create a displacement map of an object for 3D computer imaging
Figure A: Lego rig, with milk bath, webcam, lighting
Figure B: Close-up of camera head on Lego rig
Using liquid to create a displacement map of an object for 3D computer imaging
Figure A: Lego rig, with milk bath, webcam, lighting
Figure B: Close-up of camera head on Lego rig
The Milkscanner is a simple tool that allows the scanning of physical objects, via liquid displacement, and creates a displacement map for use with Moviesandbox (moviesandbox.net) or any other 3D application that allows for the use of displacement mapping.
Ingredients:
A webcam
A plastic bowl
3 Cups of milk
A custom Lego rig (or other means of holding
You can download the Milkscanner PC application and source code (creates the displacement map automatically from a webcam image) from the Milkscanner webpage: milkscanner.moviesandbox. net. If you have questions, please feel free to leave a comment on the Moviesandbox forums at: forums. moviesandbox.net.
1. Scanning
Fix the webcam above the bowl (you don’t necessarily have to use a Lego rig, but it is a fast way to build and adjust) and put the object to be scanned camera) in it (Figure C).
Figure C: The object to be scanned in the empty bowl
Figure D: The height map
Figure E: The color map
Figure F: The finished unreal 3D model
Figure G: Using soda as the liquid and a simple camera mount made from a soldering third hand
Figure H: Full body scanning using a kiddie pool and ink
Figure I: 3D rendering of the scanning point cloud
Note: The scanner can only scan half an object at a time.
Now, begin the process of covering the object in milk. This displacement process basically create a series of visual “slices” through the object in your image-capturing software. You then subtract the white part from the pictures that the webcam takes, and the remaining images serve as the slices. From these, you build your 3D rendering. The process involves adding milk, three tablespoons at a time, and taking another picture. Through this sequence, a series of consistent visual components are created, three spoonfuls of liquid at a time.
2. Use your displacement map
After creating a displacement map from the scanning process, you can use it with the Trace Tool and bring it into Moviesandbox. How this all works will be much clearer after you watch the YouTube video at youtube.com/watch?v=XSrW-wAWZe4.
You can also import it as a displacement map in Blender or Maya or any other application that supports displacement maps. Remember: the displacement map can only cover half the object.
That’s all there is to it. Enjoy!
Update: Check out a life-size version of the milkscanner, where people can scan their bodies using a cheap swimming pool, a webcam, and ink: vimeo.com/1190405.
Friedrich Kirschner is a filmmaker, visual artist, and software developer. He re-purposes computer games and real-time animation technology to create animated narratives and interactive performances.
