Thin Film

This glass model describes thin glass materials that show perfect (mirror) reflection and transparency. Thin Film models are very accurate models and are great for assigning to thin surfaces, such as windows and thin transparent plastics. Although you could also use a glass material with transmittance enabled and index of refraction set to 1, it is recommended to use the glass model whenever you want to achieve transparency.

  • Transmittance: The amount of light that passes through a material
  • Interference: Makes a surface iridescent, simulating a phenomenon called thin film interference. You may have seen this in soap bubbles, oil slicks on water, or peacock feathers. When light waves come into contact with a thin film, some waves are reflected from the top surface while others penetrate the film, hit the bottom surface, and are reflected. When these light waves interact, momentary streaks of color result. The iridescent colors change when the viewing angle is changed
  • Thickness: The thickness changes the iridescence level. 200-1000 is a good general range for making a visible change
  • Bump: Adds texture to the material at a macroscopic level. A bump map gives the illusion of texture without physically distorting the geometry, minimizing rendering time