_{specular ray depth keyframed over time (1-50)}

This simple tutorial shows you how to create an infinity mirror scene. It demonstrates what happens when a light is traced multiple times inside a reflective cube. The specular ray depth is increased to reveal multiple reflections inside the cube. The scene consists of a simple reflective tapered cube with a point light inside it (far end) and a camera pointing at it (also inside the cube).

A scene file can be downloaded here.

Scene

• Start off by creating a cube and scaling it out in one direction.

• Select the end face of the cube and taper it out slightly. This will help to create more internal reflections.

• Create a point light and position it towards the back face (tapered end) of the tapered cube.

• Create a camera and position it at the other end of the cube (inside it) pointing at the point light.

  

  _{Camera pointing at a point light inside a tapered reflective cube}

Shading

• Assign a standard surface shader to the cube and change the following attributes:
• Reduce the base weight to 0. We only want to see specular reflections inside the cube.
• Reduce the specular roughness to a very low amount. Something like 0.004. This value will depend on how high the specular ray depth is set. With a high specular roughness value and a high specular ray depth the resulting render may look too bright.
• Render the scene. You should see something like the render below using the default Arnold render settings.

_{Render using the default specular ray depth: 1}

Specular Ray Depth

• Try increasing the specular ray depth to see more internal reflections of the point light.