View source for Creating custom Portal 2 funnel music

{{p2 topicon}}
{{for|more info on Soundscripts and Sound Operators|[[Soundscripts]]}}
This article will cover the creation of custom [[Soundscripts]] that will enable custom [[prop_tractor_beam|funnel/tractor beam]] music to be played in tandem with your custom music in {{portal2|2}} levels. 
==Overview==
In {{portal2|1}}, chambers that have '''Tractor Beams'''/'''Excursion Funnels''', or simply '''funnels''', contain a custom soundtrack that plays whenever a player enters a funnel. This logic is contained within the sound script used for the music in the chamber, which utilizes Sound Operators to enable these tracks. In this article, you will learn how to create your soundscript that will toggle between your normal music and your funnel music.
{{Important|Your funnel and normal music tracks must be looped to work correctly. See the [[Looping a sound]] tutorial for instructions on how to do this.}}

==Tutorial==
===Soundscript Creation===
To begin, navigate to {{path|<steam dir>\steamapps\Portal 2\portal2\scripts}} and copy {{file|game_sounds_music|txt}}. Paste this in {{path|Portal 2\portal2_dlc3\scripts}} (if you do not have a {{path|portal2_dlc3}} folder, make one).
{{Tip|For {{p2ce}}/{{Portalrev}}, the game already registers any new soundscript files on startup, so you can just create your own file and name it game_sounds_music_<yournamehere>.txt. Just paste the required code on the first line.}}
Now, open this file, and navigate to this line:
<syntaxhighlight lang=php highlight=1>
// // triple laser
// "music.laser_node_01.play"
// {
// 	"channel"		"CHAN_STATIC"
// 	"soundlevel"	"SNDLVL_70dB"
// 	"volume"		"1.0"
</syntaxhighlight>

Now, copy and paste this code '''''above''''' <code>// // triple laser</code>:
<syntaxhighlight lang=php>
//
// your_level_name_here
//
"music.your_level_name_here_tbin" // Funnel music
{
	"channel"		"CHAN_STATIC"
	"soundlevel"	"SNDLVL_NONE"
	"volume"		"0.8"


	"wave"	"*music/your_tbmusic_here.wav" // Your funnel music


	"soundentry_version" "2"
	"operator_stacks"
	{
		"start_stack"
		{
			// Random Offset logic
			"random_offset"
			{
				"operator" "math_random"
				"input_min" "0.0"
				"input_max" "126"
			}

			"negative_delay"
			{
				"operator" "math_float"
				"apply" "mult"	
				"input1" "@random_offset.output"
				"input2" "-1.0"	
			}
			"delay_output"
			{
				"operator" "sys_output"
				"input_float" "@negative_delay.output"
				"output" "delay"
			}
		}

		"update_stack"
		{
			"import_stack" 	"update_music_stereo"
			"mixer"
			{
				"mixgroup" "unduckedMusic"
			}

			"volume_fade_in"
			{
				"input_max" "3.0"
				"input_map_min" "0.05"
			}
			"volume_fade_out"
			{
				"input_max" "0.75"
				"input_map_min" "0.05"
			}
			"volume_lfo_time_scale"
			{
				"input2" "0.3"	
			}
			"volume_lfo_scale"
			{
				"input2" "0.4"
			}

		}
	}
}

"music.your_level_name_here_b1" // Normal music
{
	"channel"		"CHAN_STATIC"
	"soundlevel"	"SNDLVL_NONE"
	"volume"		".8"


	"wave"	"*music/your_music_here.wav" //Your normal music


	"soundentry_version" "2"
	"operator_stacks"
	{
		"update_stack"
		{
			"import_stack" 	"update_music_stereo"
			"volume_fade_out"
			{
				"input_max" "3.0"
				"input_map_min" "0.05"
			}

			"import_stack" "p2_update_music_play_tbeam"
			"play_entry"
			{
				"entry_name" "music.your_level_name_here_tbin"
			}	
			"stop_entry"
			{
				"match_entry" "music.your_level_name_here_tbin"
			}
		}
	}
}
</syntaxhighlight>

Use your text editing program's find and replace function to replace "your_level_name_here" with your level name, then replace "your_tbmusic_here" and "your_music_here" with the paths to your funnel and normal music, respectively. Now, save this file.

====Optional: Syncronize the funnel and main music====
The soundscript provided above by default starts the funnel music at a random time. If your tracks perfectly match up and would like your funnel music to be synced up with your main music in-game, you will need to replace the logic managing the randomized offset with synchronization logic in its place.<br/>
Locate these lines containing the "start_stack" section in the first soundscript:
<syntaxhighlight lang=php highlight=4-27>
"soundentry_version" "2"
	"operator_stacks"
	{
		"start_stack"
		{
			// Random Offset logic
			"random_offset"
			{
				"operator" "math_random"
				"input_min" "0.0"
				"input_max" "126"
			}

			"negative_delay"
			{
				"operator" "math_float"
				"apply" "mult"	
				"input1" "@random_offset.output"
				"input2" "-1.0"	
			}
			"delay_output"
			{
				"operator" "sys_output"
				"input_float" "@negative_delay.output"
				"output" "delay"
			}
		}

		"update_stack"
		{
		...
</syntaxhighlight>
Now, copy the following code and paste it over the above highlighted code:
<syntaxhighlight lang=php>
		"start_stack"
		{
            "import_stack" "start_sync_to_entry"
				
			"elapsed_time"
			{
				"entry" "music.your_level_name_here_b1"
			}
			"duration_div"
			{
				"input2" "1"
			}
			"div_mult"
			{
				"input1" "1.0"
			}
		}
</syntaxhighlight>
Now, it should look like this:
<syntaxhighlight lang=php highlight=4-31>
"soundentry_version" "2"
	"operator_stacks"
	{
		"start_stack"
		{
            "import_stack" "start_sync_to_entry"
				
			"elapsed_time"
			{
				"entry" "music.your_level_name_here_b1"
			}
			"duration_div"
			{
				"input2" "1"
			}
			"div_mult"
			{
				"input1" "1.0"
			}
		}

		"update_stack"
		{
		...
</syntaxhighlight>
Now, your music should sync up perfectly when you exit and enter the funnel. Remember, this soundscript syncs the times of the music files and does not match the waveforms. If your sounds do not perfectly match up, or at least closely enough, there will be a noticeable difference when switching between them.
{{Bug|When the tunnel soundscript gets looped, it will always loop to the beginning of the track, even if the beginning loop point is placed further in the track. There is no known fix for this issue.
{{workaround|Edit the loop points of both your normal track and your tunnel track to loop at the beginning.}}|tested = {{p2ce}}}}

===Selecting the file in Hammer===
Now, you will need to play the sound in-game. Open your map in {{hammer|2}} and create an {{ent|ambient_generic}}, then give it these properties:

{| border=1 cellpadding="2" cellspacing="1"
|-! align=left style="background:#DCDCDC; color:black" 
!! Property Name !! Value
|-
| Name (<code>targetname</code>)
| main_music_1
|-
| Sound Name (<code>message</code>)
| music.<your_level_name_here>_b1
|}

Remember to use the "b1" soundscript, as this contains the actual logic for the toggle. Now for spawnflags, make sure that "Infinite Range" is toggled and "Is NOT Looped" is untoggled. You can optionally have this sound be enabled by default, or you can have an activator (e.g. a {{ent|trigger_once}}).

==Conclusion==
If you followed this tutorial closely enough, you should now have your soundscript that automatically changes between funnel and main music upon entering and exiting a funnel. Remember, when sharing your map, to pack this file using [[BSPZIP]] or a similar program, so it plays correctly for others! Refer to the [[Soundscripts]] and [[Sound operators]] pages for documentation on the different operators and functions of Soundscripts if you would like to customize this logic further.

[[Category:Portal 2 Level Design]]
[[Category:Tutorials]]