Shredder

A shredder in Portal 2.

Shredders (a.k.a. grinders) are spinning blades in Portal 2 that destroy objects and players dropped into them. They function just like bottomless pits and deadly goo, but are factory themed.

Creation

Note:Although the shredder model has rotating animations, there is a "pop" every time the animation is about to loop. For this reason, the method below is recommended.

1. Create a new map file to hold the shredder instance.

2. Create a long, thin brush. Tie it to a func_rotating entity with the following settings:

Property Name	Value
Name	shredder1_left_axle
Blocking Damage	500

3. Create another long, thin brush. Tie it to a func_rotating entity with the following settings:

Property Name	Value
Name	shredder1_right_axle
Blocking Damage	500

4. Create a prop_dynamic entity with the following settings:

Property Name	Value
Name	shredder1_left
Parent	shredder1_left_axle
World Model	models/props_gameplay/shredder_left_b.mdl

5. Create a prop_dynamic entity with the following settings:

Property Name	Value
Name	shredder1_right
Parent	shredder1_right_axle
World Model	models/props_gameplay/shredder_right_b.mdl

6. Position the props so that the teeth interlock and the brush entities are in the center of their respective props.

7. Create a 256×1024×128 brush where things would fall into it. Tie the brush to a trigger_hurt entity with the following settings:

Property Name	Value
Name	shredder1_trigger_hurt
Damage	1000
Damage Cap	1000
Damage Type	CRUSH

8. Create a brush in front of that brush and tie it to a trigger_multiple entity with the following settings:

Property Name	Value
Name	shredder1_dissolver
Delay Before Reset	5

Tick the "Physics Objects" flag and add the following output:

	My Output	Target Entity	Target Input	Parameter	Delay	Only Once
	OnTrigger	!activator	Dissolve		0.00	No
	OnTrigger	!activator	SelfDestructImmediately		0.00	No

9. Create a logic_relay with the following settings:

Property Name	Value
Name	shredder1_relay_on

and the following outputs:

	My Output	Target Entity	Target Input	Parameter	Delay	Only Once
	OnTrigger	shredder1_trigger_hurt	Enable		0.00	No
	OnTrigger	shredder1_dissolver	Enable		0.00	No
	OnTrigger	shredder1_axle_left	StartForward		0.00	No
	OnTrigger	shredder1_axle_right	StartForward		0.25	No

10. Create a logic_relay with the following settings:

Property Name	Value
Name	shredder1_relay_off

and the following outputs:

	My Output	Target Entity	Target Input	Parameter	Delay	Only Once
	OnTrigger	shredder1_trigger_hurt	Disable		0.25	No
	OnTrigger	shredder1_dissolver	Disable		0.00	No
	OnTrigger	shredder1_axle_left	Stop		0.00	No
	OnTrigger	shredder1_axle_right	Stop		0.25	No

11. Create a func_instance_io_proxy with the following settings:

Property Name	Value
Name	shredder1_proxy

and the following outputs:

	My Output	Target Entity	Target Input	Parameter	Delay	Only Once
	OnProxyRelay	shredder1_relay_on	Trigger		0.00	No
	OnProxyRelay	shredder1_relay_off	Trigger		0.00	No

12. Save and close the file.

To use, create a func_instance in your map and set the VMF filename to the name of the file you saved your shredder instance in. Then use the following outputs to turn the shredder on or off:

	My Output	Target Entity	Target Input	Parameter	Delay	Only Once
	<on condition>	<Fix-up Name of the func_instance>	instance:shredder1_relay_on;Trigger		0.00	No
	<off condition>	<Fix-up Name of the func_instance>	instance:shredder1_relay_off;Trigger		0.00	No