Blender 3D: Noob to Pro/Creating a Light Probe

< Blender 3D: Noob to Pro

The light probe is, in the simplest terms, a photograph of your environment. they work in very much the same way that reflection maps do, and are made the same way.

Equipment:

  1. A pure silver ball. Try a plastic Christmas tree ball ornament.
  2. A camera, preferably digital. If you have a high-end digital camera, you'll have less work ahead.
  3. A place you'd like to capture the lighting from. Try laying different things in your environment to get a good idea.
  4. Something to fire the shutter without touching the camera. For digital cameras, Paul Debevec recommends using a program that will take all the pictures for you.
  5. A tripod.

Set it up like so. Remember that the height of your camera and the height of the ball relative to each other controls the angle at which the horizon will be shot. In other words, shoot the ball at the same angle that you plan to shoot your 3D scene in. If your scene is animated... consider making a similar rig except attaching your reflective ball to a video camera as was done for Flight of the Navigator.

Lightprobe hardware diagram.png

(note from a VFX pro who is using this technique for years: on a mirror ball everything is reflected except the area right behind the sphere opposite to the camera - where the tape is on the above picture)

The process:

  1. Set up your rig and take a series of images with varying exposure times.
  2. Taking 2 sets of pictures, each offset by 90 degrees, will enable you to get better coverage of the background and eliminate the reflection of the camera taking the picture.