gzdoom/wadsrc/static/zscript/shared/skies.txt

class SkyViewpoint : Actor native 
{
	default
	{
		+NOSECTOR
		+NOBLOCKMAP
		+NOGRAVITY
		+DONTSPLASH
	}
}

class SkyPicker : Actor native 
{
	default
	{
		+NOSECTOR
		+NOBLOCKMAP
		+NOGRAVITY
		+DONTSPLASH
	}
}

class SkyCamCompat : SkyViewpoint native
{
}

class StackPoint : SkyViewpoint native 
{
}

class UpperStackLookOnly : StackPoint
{
}

class LowerStackLookOnly : StackPoint
{
}


class SectorSilencer native 
{
	default
	{
		+NOBLOCKMAP
		+NOGRAVITY
		+DONTSPLASH
		RenderStyle "None";
	}
}