Image Credit: Screenshot via Youtube
How do you paint a weirdly shaped 3D-printed object with a complex pattern? Take it for a dip in the pool.
A new color technique pioneered by researchers at a computer graphics and visualization lab at Zhejiang University [PDF] involves dipping an object in water while coating it in a multi-colored film. This paints the object in one stroke with zebra stripes, leopard print, or whatever other pattern you might want.
It builds on a process called hydrographic painting, which, while similar in concept, isn't terribly effective. The plastic film floated on top of the water, and it was meant to stretch across the dipped object. But it often went awry, creating an inconsistent splash of color or even tears in the paint.
Instead, computational hydrographic printing involves creating a 3D scan of the object (say, a mask) before it's lowered into the water. An algorithm takes into account the way that the plastic film will bend and distort as the object is lowered onto it by a robotic arm, drawing the pattern accordingly. The pattern is then printed out on a regular office printer and then placed on top of the pool of water. The result is a perfectly glued-on pattern, every time.
By dipping the object in the pool multiple times, you can even create a texture to the paint, as if it was painted by hand. (In case you needed to pass off some mass-produced 3D printed wares as homemade Etsy items.)