Creating an energy ball launcher and catcher

Introduction

The purpose of this tutorial is to illustrate how to create a single ball launcher and have a single ball catcher as its target. Both, the launcher and the catcher instructions will detail how the basic animations as well as the visual and sound effects work.

The Aperture Science High Energy Pellet Launcher

Launcher assembly.

The launcher is comprised of three entities:

• func_brush
• point_energy_ball_launcher
• prop_dynamic

The model used is:

• models/props/combine_ball_launcher.mdl

To create the launcher:

1. Create a prop_dynamic entity (Shift+E) with a World Model set to "models/props/combine_ball_launcher.mdl" and the Name key of "ball_launcher".

2. Place the new entity where you want it in your map.

3. Create a point_energy_ball_launcher entity and set its name to "ball".

4. Place the new entity inside the dome of the "ball_launcher" model.

5. Create a new brush 20 units or so square and 1 unit thick with the nodraw texture.

6. Turn this brush into a func_brush entity (Ctrl+T) and name it "ball_launcher_shield".

7. Place the "ball_launcher_shield" so that it is touching the black circular shield of the "ball_launcher model".

8. Open up the point_energy_ball_launcher properties and set these outputs:

	My Output	Target Entity	Target Input	Parameter	Delay	Only Once
	OnPostSpawnBall	ball_launcher	SetAnimation	close	0.00	No
	OnPostSpawnBall	ball_launcher_shield	Disable	<none>	0.00	No
	OnPostSpawnBall	ball_launcher_shield	Enable	<none>	2.00	No

9. Adjust the keyvalues of point_energy_ball_launcher to set the desired Direction, Speed, Type, and Life of the ball.

The Aperture Science High Energy Pellet Launcher is now complete.

Note:If necessary, you can also place the point_energy_ball_launcher outside of the "ball_launcher" model and remove the "ball_launcher_shield" outputs.

The Aperture Science High Energy Pellet Target

Target assembly.

The target is comprised of eleven entities:

• ambient_generic
• env_sprite
• filter_combineball_type
• func_tracktrain
• logic_relay
• path_track (2)
• point_spotlight
• prop_dynamic (2)
• trigger_multiple

The models used are:

• /models/props/combine_ball_catcher.mdl
• /models/Effects/combineball.mdl

To create the catcher:

1. Create a prop_dynamic entity with a World Model key pointing to "models/props/combine_ball_catcher.mdl" and the Name set to "ball_trap".

2. Place the entity where you want it in your map.

Note:The model requires a hole of at least 32 units square and 8 units deep. Otherwise, when the model animates to its closed state, part of the model will be hidden in a wall.

3. Create a filter_combineball_type entity and name it "filter_ball".

4. Set the ball type for "filter_ball" to "Launched by point_combine_ball_launcher".

5. Create a cylinder brush with 8 faces, and size it to same the length and width, as the Dynamic prop. Texture it with the trigger texture to cover the opening of the "ball_trap" model.

6. Turn this brush into a trigger_multiple entity and name it "trigger_ball_trap", also set the filter_name to "filter_ball". Make sure to have the flags Physics Objects selected.

7. Create a prop_dynamic entity with a World Model of "models/Effects/combineball.mdl", set its Parent to "ball_trap" and Name it "ball_trap_ball".

8. Create a env_sprite entity, set its Sprite Name to "sprites/physring1.vmt", set its Parent to "ball_trap" and Name it "ball_trap_sprite".

9. Place both "ball_trap_ball" and "ball_trap_sprite" somewhere near the front of the "ball_trap" model.

10. Create a logic_relay entity and name it "relay_ball_trap_spawn".

11. Open up the logic_relay properties and set these outputs:

	My Output	Target Entity	Target Input	Parameter	Delay	Only Once
	OnSpawn	ball_trap_ball	SetParentAttachment	ball_attachment	0.00	No
	OnSpawn	ball_trap_sprite	SetParentAttachment	ball_attachment	0.00	No

12. Create a path_track entity and name it "path_ball_trap_01", set Next Stop Target to "path_ball_trap_02".

13. Place "path_ball_trap_01" in front of and slightly above the "ball_trap" model.

14. Create a path_track entity and name it "path_ball_trap_02, set Next Stop Target to "path_ball_trap_01".

15. Place "path_ball_trap_02" behind and slightly above the "ball_trap" model.

16. Create a brush with the nodraw texture.

17. Turn this brush into a func_tracktrain entity and name it "ball_trap_door".

18. Place it slightly above the two path_track entities and behind the "path_ball_trap_01".

19. Open up the property window for "ball_trap_door" and set these keyvalues:

Property Name	Value
First Stop Target	path_ball_trap_01
Move Sound	d3_citadel.podarm_move
Start Sound	d3_citadel.podarm_move_start
Stop Sound	d3_citadel.podarm_move_stop

20. Open up the property window for "path_ball_trap_02" and set this output:

	My Output	Target Entity	Target Input	Parameter	Delay	Only Once
	OnPass	ball_trap_door	SetSpeed	0	0.00	No

21. Create a point_spotlight entity (Shift+E) and name it "ball_trap_spotlight". You may also want to disable the Dynamic Light flag.

22. Set the Color for "ball_trap_spotlight" to "255 0 0", the Beam Length is normally the length of the room, and Beam Width somewhere between 20 and 40.

23. Create an ambient_generic entity and Name it "ball_trap_sound"

24. Set the Sound Name key for "ball_trap_sound" to "AlyxEMP.Charge"

25. Open the property window for "trigger_ball_trap" and set these outputs:

	My Output	Target Entity	Target Input	Parameter	Delay	Only Once
	OnStartTouch	trigger_ball_trap	Disable	<none>	0.00	No
	OnStartTouch	ball	Disable	<none>	0.00	No
	OnStartTouch	!activator	Kill	<none>	0.00	No
	OnStartTouch	ball_trap_ball	Enable	<none>	0.00	No
	OnStartTouch	ball_trap_sprite	Enable	<none>	0.00	No
	OnStartTouch	ball_trap	SetAnimation	close	0.00	No
	OnStartTouch	ball_trap_spotlight	LightOff	<none>	0.00	No
	OnStartTouch	ball_trap_door	SetSpeed	.5	0.00	No
	OnStartTouch	ball_trap_sound	PlaySound	<none>	0.00	No

Then under the Flags tab un-check "clients" and check everything else.

The Aperture Science High Energy Pellet Target is now complete.

Note:The "ball_trap_door" sounds are drowned out by the "ball_trap_sound", you may want to adjust the delay for the PlaySound.

The theory

Energy Pellet Launcher and Target at work.

These instructions illustrate the most basic use of the launcher and catchers. Theoretically you should be able to have one launcher and multiple catchers, or even catchers that reset themselves.

See also

• Portal Level Creation