In most cases you need two types of transparency: mask-based (for example holes in paper) and refraction-based (glass and similar things). Boxshot supports both and here are some samples you may start with:

Mask-based transparency

That’s really easy. Create a PNG or TIFF file with transparency, assign it to the shape and you’ll get what you need:

transparent materials

Boxshot automatically detects that the image has an alpha-channel (transparency mask) and uses it. Please note that not all the shapes are designed to work with transparent sides, so they may not have inner geometry and may appear just transparent there.

Refraction-based transparency

Well, this is about glass, plastic and other semi-transparent materials that are used for CD boxes, wine bottles and so on. Boxshot supports semi–transparent, refractive materials and provides enough parameters to fine tune the material. The most important parameters are located in Surface and Transparency sections of the Materials panel.

  • Index of refraction — the parameter defines how strong the surface changes the direction of the refracted ray. There are tables of refraction indices for various materials that you may find in the Internet. For example water has refraction index 1.33, diamond — 2.4;
  • Opacity — defines the level of transparency of the surface. The less this level, the more rays go through it.

Here is the water ball with the fresnel reflection enabled.

transparent materials

Medium Color

Sometimes you need to render a thick not–so–transparent glass. That’s where you may use the medium color parameters. There is a special section in the materials panel for that with just two options there: attenuation and transmittance. Here’s how it works:

Transmittance defines a color that the medium has if it is attenuation centimeters thick.

Pretty simple, but needs some practice to get used to. Here are six glass cylinders with the same transmittance color and different attenuation values.

transparent materials

The cylinders themselves are 4cm in diameter. Attenuations are: 0.5cm, 1cm, 5cm, 20cm, 100cm and 800cm. As you may see, the larger the attenuation is, the more transparent the cylinders are. That’s because attenuation is a thickness that a medium needs to have to make the transmittance color.

Rough Surfaces

It is pretty much like the rough reflection, just for refraction.

refraction blur

This is useful for “old glass” or “frozen window” effects.