Refraction

Refraction is the familiar physical phenomenon of light traveling differently through different materials and thus reflecting differently off objects behind that material. For example, if you have a glass of water with a straw in it, the part of the straw that’s not in water appears to be in a different angle to the part that is in the water. This is due to water bending the light waves.

PrmanRender uses raytracing to create this effect and you can use the Refraction node to adjust the result. Without the PrmanRender node and RenderMan Pro Server software though, the Refraction node has no effect.

Inputs and Controls

Connection Type	Connection Name	Function
Input	unnamed	Either: • The 2D image you’re using for the surface texture, or • Another shader node, such as Diffuse, Specular, or Emission. Adding several shader nodes one after the other allows you to produce more complex effects.
Output	unnamed	The 3D geometry object to which you want to apply a refraction effect. If you want to apply the same effect to several objects, you can also connect a MergeGeo node here.

Connection Type

Connection Name

Function

Input

unnamed

Either:

• The 2D image you’re using for the surface texture, or

• Another shader node, such as Diffuse, Specular, or Emission. Adding several shader nodes one after the other allows you to produce more complex effects.

Output

unnamed

The 3D geometry object to which you want to apply a refraction effect. If you want to apply the same effect to several objects, you can also connect a MergeGeo node here.

Control (UI)	Knob (Scripting)	Default Value	Function
Refraction Tab
refraction index	refraction_index	1	Changes the type of refraction.
value	refraction_value	1	Sets the intensity of the refraction.

Step-by-Step Guides

Using the Refraction Node