hl2_ep2_content/materials/effects/flicker_256.vmt

"Modulate"
{
	"$translucent" 1
	"$basetexture" "effects/flicker_256"
	"$MOD2X" 1
	"Proxies"
	{
		"AnimatedTexture"
		{
			"animatedtexturevar" "$basetexture"
			"animatedtextureframenumvar" "$frame"
			"animatedtextureframerate" 24
		}
	}
}