Some objects that are transparent in AR may not be rendered transparent on VR/MR devices. This is caused by the fundamental way that the devices work.
VR/MR devices use video see through to display the real world captured through cameras on an opaque display. AR devices skip capturing the real world with cameras and use transparent optical see through displays instead.
While the color displayed on an VR/MR device doesn't have a lot of limitations, AR devices can only add light and have a hard time completely overriding what's visible in the real world.
Examples
| Color | RGBA | VR/MR | AR |
|---|---|---|---|
| black | 0, 0, 0, 0 | fully transparent | fully transparent |
| black | 0, 0, 0, 255 | black | fully transparent |
| any color half transparent | #, #, #, 128 | half transparent, alpha blent with passthrough background or clear color | half transparent, alpha blent with clear color |
Differences in the perceived color result could be caused by:
- Camera clear color being set to black with (0, 0, 0, 255) or without out an alpha channel (0, 0, 0, 0).
- Shaders that do not support an alpha channel.
- Post processing effects that clear the alpha channel.
Recommendations for a consistent perceived color result on all devices:
- Choose a clear color of black without alpha channel (0, 0, 0, 0).
- Use alpha sparingly when using AR or Passthrough.
- Check shaders for support of alpha by
- Checking code.
- Setting an main color or main texture with alpha values versus without and comparing results.