Create traffic lights

The Half-Life 2 assets already provide a model of a signal light, this tutorial will explain how a dynamic traffic light can be set up using I/O.

Required entities

• One prop_dynamic with the following keyvalues:

Keyvalue	Value
World Model	props_c17\traffic_light001a.mdl
Disable Shadows	Yes
Collide with world	Not solid

Note:"Not solid" is necessary when you want to place the lights inside the model or very close to it

• Three point_spotlights placed at roughly the right position near the model.

• One logic_auto.

• Two logic_relays.

I/O setup

The input and output logic will define how long each light will be visible, this example will use the following durations:

• Red and green - 30 seconds

• Yellow - 3 seconds

Entity names

The targetname keyvalue defines the name of the entities, the three point_spotlights should use the following names respectively: "greenLight" "redLight" "yellowLight". The first logic_relay will be named "traffLightRelay1" and the second one "traffLightRelay2".

Outputs

The logic_auto requires the following output:

	My Output	Target Entity	Target Input	Parameter	Delay	Only Once
	OnMapSpawn	traffLightRelay1	Trigger		0.00	Yes

Add these outputs to the first logic_relay:

	My Output	Target Entity	Target Input	Parameter	Delay	Only Once
	OnTrigger	yellowLight	LightOn		28.00	No
	OnTrigger	redLight	LightOff		30.00	No
	OnTrigger	greenLight	LightOn		30.00	No
	OnTrigger	yellowLight	LightOff		30.00	No
	OnTrigger	traffLightRelay2	Trigger		32.00	No

Note:This tutorial will use both logic_relays and trigger them one after another

Add these outputs to the second logic_relay:

	My Output	Target Entity	Target Input	Parameter	Delay	Only Once
	OnTrigger	greenLight	LightOff		28.00	No
	OnTrigger	greenLight	LightOn		28.50	No
	OnTrigger	greenLight	LightOff		29.00	No
	OnTrigger	greenLight	LightOn		29.50	No
	OnTrigger	greenLight	LightOff		30.00	No
	OnTrigger	yellowLight	LightOn		30.00	No
	OnTrigger	redLight	LightOn		32.00	No
	OnTrigger	traffLightRelay1	Trigger		32.00	No
	OnTrigger	yellowLight	LightOff		32.00	No

Now the map can be compiled and the traffic lights should be working!

External links

vmf + bsp + screenshots (Counter-Strike: Source!) ^{[dead link]}