3D Printing Concepts: The Play of Light

Welcome back!

Today we're going to dive into the concept of lighting. For those of you with filament printers and resin printers alike, we can get into the fun realm of designing for and choosing the right materials for lit prints. 

Printing models for use with LED candles (not fire candles, nope don't do it), there are 2 fundamental concepts to consider; material opacity & model thickness. Assuming the LED lights you'll be experimenting with are all equal, these two things will directly influence how your light will translate through the print. 

Opacity. 

Simply put, opacity is how much light transmits through a medium, sometimes referred to as light permeability. Light is essentially a wave that bounces off objects, an action called scattering. The more opaque a medium is, the less light can pass through it, scattering completely. A brick is very opaque vs window glass which is the complete opposite, entering the realm of translucency or ultimately to complete transparency. So our resin or filament will transmit light based on how opaque the material inherently is. Here's a simple reference: (brick) opaque ↔ translucent ↔ transparent (glass)

Thickness.

Opacity works in tandem with the thickness of the print, but it behaves differently depending on the degree of opacity.

OPAGUE: 

Imagine a Halloween pumpkin. The thick gourd walls block the light, however if the outside is scraped down we begin to see some light coming through even though the gourd walls are very opaque. This gives us the ability to achieve the sharpest and most controlled details.

TRANSLUCENT: 

A frosted light bulb shade is a great example of a translucent medium. The light transmits through the frosted glass, scattering some light while also allowing light through, giving off the look of a soft glow. This is particularly nice when we want to achieve a whimsical fuzzy appearance, but not a sharp defined detail.

TRANSPARENT:

Our go to example of a window pane demonstrates that almost all light passes through, giving off neither a soft glow nor a distinct edge. This is ideal for instances when the translucent material is meant to a different purpose than decorative light effects, say a clear protective barrier. 

So how about those baubles?

1. Using a very opaque material is ideal when we want to enhance only specific portions of the print. In our example, the bauble has the P3D logo which we want to be more lit than the surrounding model. The logo has a much thinner wall than the rest, so the light will permeate the material, lighting up the logo, best seen in the white version as it's the most opaque material. 
2. Using a translucent material is ideal when the goal is to evenly light up the entire print. The yellow print is the most translucent material. When lit and compared to the other prints, the logo is washed out. Not what we were going for, so to make the bauble usable we decided to fill the recesses with glitter!

Stay tuned for the next post where we get into how to apply glitter to prints.

Thanks for stopping by!