<cat>Ref.Hook</cat> These hooks are used inside of a Lua effect. Lua effects are stored in either the &lt;kbd&gt;/lua/effects&lt;/kbd&gt; directory or in a gamemode in &lt;kbd&gt;/gamemodes/&lt;gamemodename&gt;/entities/effects&lt;/kbd&gt;. Effects are entities with the class CLuaEffect, and as such, <page>Entity</page> functions are usable on them (using the &lt;kbd&gt;self&lt;/kbd&gt; argument). These hooks are used inside of a Lua effect. Lua effects are stored in either the <kbd>/lua/effects</kbd> directory or in a gamemode in <kbd>/gamemodes/<gamemodename>/entities/effects</kbd>. Effects are entities with the class CLuaEffect, and as such, <page>Entity</page> functions are usable on them (using the <kbd>self</kbd> argument). An EFFECT is made using either a combination of the <page>EFFECT:Init</page>, <page>EFFECT:Render</page> and optionally the <page>EFFECT:Think</page> hook. Another way is to create all particles in one go in the `Init` hook and don't use the other hooks at all. <example> <description>Creates a particle effect using a combination of the Init and the Think hooks.</description> <code> function EFFECT:Init( data ) self.data = data self.particles = 4 end function EFFECT:Think() return true end function EFFECT:Render() local vOffset = self.data:GetOrigin() + Vector( 0, 0, 0.2 ) local vAngle = self.data:GetAngles() local emitter = ParticleEmitter( vOffset, false ) for i=0, self.particles do local particle = emitter:Add( "effects/softglow", vOffset ) if particle then particle:SetAngles( vAngle ) particle:SetVelocity( Vector( 0, 0, 15 ) ) particle:SetColor( 255, 102, 0 ) particle:SetLifeTime( 0 ) particle:SetDieTime( 0.2 ) particle:SetStartAlpha( 255 ) particle:SetEndAlpha( 0 ) particle:SetStartSize( 1.6 ) particle:SetStartLength( 1 ) particle:SetEndSize( 1.2 ) particle:SetEndLength( 4 ) end end emitter:Finish() end </code> </example> <example> <description>Creates a particle effect using only the Init hook. To use this effect in a loop one needs to create a new instance of this effect every drawn frame.</description> <code> function EFFECT:Init( data ) local vOffset = data:GetOrigin() + Vector( 0, 0, 0.2 ) local vAngle = data:GetAngles() local emitter = ParticleEmitter( vOffset, false ) for i=0,4 do local particle = emitter:Add( "effects/softglow", vOffset ) if particle then particle:SetAngles( vAngle ) particle:SetVelocity( Vector( 0, 0, 15 ) ) particle:SetColor( 255, 102, 0 ) particle:SetLifeTime( 0 ) particle:SetDieTime( 0.2 ) particle:SetStartAlpha( 255 ) particle:SetEndAlpha( 0 ) particle:SetStartSize( 1.6 ) particle:SetStartLength( 1 ) particle:SetEndSize( 1.2 ) particle:SetEndLength( 4 ) end end emitter:Finish() end function EFFECT:Think() return false end function EFFECT:Render() end </code> </example>