Trail using triangle strip and a vbo

[shadmar]

It works but seem to render only every other frame.

Maybe someone can figure it out:

 

function Script:Start()
  	 --make a vertex buffer
       vbo = { }
       maxvbo = 100

       mat=Material:Create()
       mat:SetBackFaceCullMode(false)

       --fill it with nonsense positions
       local pos=self.entity:GetPosition(true)
       for x=1,maxvbo,2 do
          	 --just insert some data
               table.insert(vbo,Vec3(pos.x-.5,pos.y+x,pos.z))
               table.insert(vbo,Vec3(pos.x+.5,pos.y+x,pos.z))
       end

       lasttime=0

       --create a model
       model = Model:Create()
       model:SetOcclusionCullingMode(false)
    model:SetColor(1.0,0.0,1.0)

       --make surface
    local surface = model:AddSurface()

       --add vertices
       for k,v in ipairs(vbo) do
           surface:AddVertex(v.x,v.y,v.z, 0,0,-1)	   
    end

       --make triangle strip
       surface:AddTriangle(2,1,0)
    surface:AddTriangle(0,3,2)
       for x=1,maxvbo-4,2
       do
           surface:AddTriangle(x+3,x+1,x+2)
           surface:AddTriangle(x+2,x+4,x+3)
       end

       surface:Update()
    model:UpdateAABB(Entity.LocalAABB)
    model:UpdateAABB(Entity.GlobalAABB)

       model:SetMaterial(mat)
end


function Script:UpdateWorld()

   if Time:GetCurrent()-20 > lasttime then

       --get positions
       local pos=self.entity:GetPosition(false)

       table.insert(vbo,Vec3(pos.x+.5,pos.y,pos.z))
       table.insert(vbo,Vec3(pos.x-.5,pos.y,pos.z))

       --remove last vertex each loop
       table.remove(vbo,1)
       table.remove(vbo,2)

       lasttime=Time:GetCurrent()

       --ok move all vertices according to vbo

       local surface = model:GetSurface(0)
    for  v=0, surface:CountVertices()-1 do
           surface:SetVertexPosition(v,vbo[v+1])
       end

       surface:Update()
    model:UpdateAABB(Entity.LocalAABB)
    model:UpdateAABB(Entity.GlobalAABB)

   end
end

[shadmar]

Fixed. / updated.