The chroma key feature allows you to control where a viewer sees virtual content in the mixed reality environment. When chroma key is in use, a predefined color in your physical environment is replaced with virtual content.
Preparing your environment for chroma key
Chroma key works best in good, soft lighting. Make sure the chroma key surface is evenly lit and avoid reflective objects in your environment, as the chroma key background can become visible in these places. Try to use neutral-colored lights with identical color temperatures.
Depending on your intended use, we recommend that you choose a chroma key color that is clearly distinct from human skin tones. Green and blue are typically good choices. Chroma keying requires a bright color tone as its target, and therefore black, white, or gray will not work.
Chroma key can be used either as a background for the scene or on smaller individual surfaces. When using a colored canvas as backdrop, make sure not to leave wrinkles, creases, or shadows on the surface. It helps to leave some distance between foreground elements and the background to avoid shadows falling on the canvas. When placing smaller individual elements into the scene, ensure that they are all the same color and lit similarly.
See our Developer Portal for more technical information on how to set up your environment for use with chroma key.
Chroma key settings
In Varjo Base, the chroma key feature is found under the System tab. Open Chroma key color to pick and adjust the color used for chroma key. Enable Use chroma key in all applications to force all applications to use chroma key and the mixed reality cameras. Areas in the chroma key color are replaced with application content.
You may see one of the following messages in the System tab:
| Configuration locked by another application. | Another application is using the chroma key configuration. All chroma key settings are disabled. The settings will be released once the application is closed or is no longer using the configuration. |
| Chroma key set by application. Sampling a new color will erase the current chroma key. | Another application has set the current chroma key configuration. Editing the configuration will replace the current one. |
Picking a chroma key color
To pick a chroma key color, navigate to the System tab and open Define chroma key color.
You can preview the current chroma key configuration using the Preview chroma key setting. The chroma key mask is visualized using the color you select in the drop-down list.
Start Pick colors with headset to select a chroma key color using the mixed reality cameras on your headset. While holding the headset, point it at your target color and use the Space bar or Action button 
(or Application button) on your headset to pick color samples. The color you pick is replaced with the preview color in the headset view.
We recommend you pick colors from multiple points in the environment to account for differences in lighting and surface color. The color picker is additive: each selection increases the color range in use. Select Stop to quit the color picker.
Reset will return the original color values. You can also load a color configuration or save the current one.
Your chroma key color can be fine-tuned under Adjust chroma key color. The sliders for Hue and Hue tolerance adjust the chroma key color tone and the tolerance for color variation. Saturation tolerance and Value tolerance adjust the tolerance for bright and dark areas respectively.
Accept the current chroma key color and return to the System tab by clicking Done.
Revert to the previous configuration by selecting Cancel or closing the settings menu.