- Start Fade Dist/Pixels (fademindist)
- Distance at which the prop starts to fade. If 'Screen Space Fade' is selected, this represents the number of pixels wide covered by the prop when it starts to fade. For less than 0, use fademaxdist.
- End Fade Dist/Pixels (fademaxdist)
- Maximum distance at which the prop is visible. If 'Screen Space Fade' is selected, this represents the minimum number of pixels wide covered by the prop when it fades. 0 for don't fade out.
- Fade Scale (fadescale)
- If you specify a fade in the worldspawn, or if the engine is running under dx7, then the engine will forcibly fade out props even if fademindist/fademaxdist isn't specified. This scale factor gives you some control over the fade. Using 0 here turns off the forcible fades.
- Comma-separated list of interaction layers.