Beam Script

[reepblue]

A beam script that'll stretch a sprite from one point to another. Useful for lasers and cables. You can enable or disable auto updating if it isn't necessary.

 

--[[
This script will create a simple sprite that looks like a beam or a cable.
The beam is does not do any raycasting along and gets updated via the physics step.
You can apply a script to the beam to change it's appearance such as flickering or pulsing.
]]--
Script.fxscriptfile=""--path "Beam Script" "Script (*.lua):lua|Scripts/Objects/Effects"
Script.beamcolor=Vec4(1,1,1,1) --color "Beam Color"
Script.beambrightness=1.0--float "Beam Brightness"
Script.materialfile=""--path "Material" "Material (*.mat):mat|Materials"
Script.beamwidth = .25 --float "Beam Width"
Script.startpoint = nil --entity "Start Position"
Script.endpoint = nil --entity "End Position"
Script.beamhidden = false --bool "Hidden"
Script.autoupdate = true --bool "Auto-Update"

function Script:Start()
 -- Ignore pickers from picking us!
 self.entity:SetPickMode(0)

 -- Beam Sprite
 self.sprite = Sprite:Create()
 local material = Material:Load(self.materialfile)
 if material then
   self.sprite:SetMaterial(material)
   material:Release()
 else
   System:Debug("Beam material is missing.")
 end
 self.sprite:SetViewMode(6)--Rotate around z axis
 if self.fxscriptfile ~= nil then self.sprite:SetScript(self.fxscriptfile) end
 self.sprite:SetColor(self.beamcolor)
 self.sprite:SetIntensity(self.beambrightness)
 if not self.beamhidden then self.sprite:Show() else self.sprite:Hide() end

 -- If the first feild is nil, assume the user want's it to be the entity that holds this script.
 if self.startpoint == nil then
   self.startpoint = self.entity
 end

 -- A end point is needed. If nil, report error.
 if self.endpoint == nil then
   System:Debug("End point is nil.")
 end

 -- Only draw the beam once of auto-update is false.
 if not self.autoupdate then
   self:UpdateBeam()
 end
end

function Script:UpdateBeam()
 -- Return if the beam is hidden.
 if self.sprite:Hidden() then return end

 local p0 = self:GetStartPoint()
 local p1 = self:GetEndPoint()

 self.allignvector = p0 - p1
 self.sprite:SetPosition((p0+p1)/2)
 self.sprite:AlignToVector(self.allignvector:Normalize(),2)

 -- Find distance between the two points.
 local distanceX = math.pow(p0.x - p1.x, 2)
 local distanceY = math.pow(p0.y - p1.y, 2)
 local distanceZ = math.pow(p0.z - p1.z, 2)
 local total_distance = math.sqrt(distanceX + distanceY + distanceZ)

 -- Modify the size of the beam based on the 2 points.
 self.sprite:SetSize(self.beamwidth, math.abs(total_distance))
end

function Script:UpdatePhysics()
 if self.autoupdate then
   self:UpdateBeam()
 end
end

function Script:GetStartPoint()
 return self.startpoint:GetPosition(true)
end

function Script:GetEndPoint()
 return self.endpoint:GetPosition(true)
end

function Script:TurnOn()--in
 if self:IsOn() then return end
 self.sprite:Show()
end

function Script:TurnOff()--in
 if not self:IsOn() then return end
 self.sprite:Hide()
end

function Script:Toggle()--in
 if self:IsOn() then
   self:TurnOff()
 else
   self:TurnOn()
 end
end

function Script:IsOn()
 return not self.sprite:Hidden()
end

function Script:Release()
 self.sprite:Release()
end

 

If you're looking for a laser beam in which the end position is the end of a pick test, you can check out this post for details on how to do it. This script just has the basic functionality.

 

You can reuse the script for more complex effects by ether cloning the script, or setting the script to an entity and then modifying it's values like.

 

-- Make Pivot
local p = Pivot:Create()
-- Set Script to Pivot
p:SetScript("scripts/objects/effects/beam.lua")
-- Modify some values
p.script.beamcolor=Vec4(1,0,0,1)
p.script.autoupdate = false
....
....