Lab 031 – Faking some Stage Lights

Using a cone shape, material alpha, and a spotlight to create a fake stage light effect.

We could create a more complex effect using shader graph, but somethings a faking it is good enough. This lab is something I mocked up quickly during the MIT Reality Hack.

How it works

1. Parent Transform: an empty container for the cone mesh and light
2. Cone Mesh: I created a cone mesh and sized it to hide the end below the floor of the scene. I moved the cone down on the Y axis in the parents coordinate space. This will position the top of the cone at the parent position. The material uses an opacity to let us look through it. The diffuse and emissive colors are set to the same color as the light. I also culled the front faces so we only ever see the “inside” of the cone.
3. Spot Light: I positioned this at the parent position with a inner and outer angles to shape the light to shine in the cone.

All the work was done in Reality Composer Pro, so there is no code to share for this lab. You could download the USDA file for the scene to play with it in your project.

Download the Xcode project with this and many more labs from Step Into Vision.