modelchange.lua

     /**************************************************
    SWEP Construction Kit base code
        Created by Clavus
    Available for public use, thread at:
       facepunch.com/threads/1032378
**************************************************/

/*

function SWEP:Initialize()
 self:SetWeaponHoldType(self.HoldType)
    // other initialize code goes here

    if CLIENT then

        self:CreateModels(self.VElements) // create viewmodels
        self:CreateModels(self.WElements) // create worldmodels

        // init view model bone build function
        self.BuildViewModelBones = function( s )
            if LocalPlayer():GetActiveWeapon() == self and self.ViewModelBonescales then
                for k, v in pairs( self.ViewModelBonescales ) do
                    local bone = s:LookupBone(k)
                    if (!bone) then continue end
                    local m = s:GetBoneMatrix(bone)
                    if (!m) then continue end
                    m:Scale(v)
                    s:SetBoneMatrix(bone, m)
                end
            end
        end

    end

end


function SWEP:OnRemove()

    // other onremove code goes here

    if CLIENT then
        self:RemoveModels()
    end

end

*/

if CLIENT then

    SWEP.vRenderOrder = nil
    function SWEP:ViewModelDrawn()

        local vm = self.Owner:GetViewModel()
        if !ValidEntity(vm) then return end

        if (!self.VElements) then return end

        if vm.BuildBonePositions ~= self.BuildViewModelBones then
            vm.BuildBonePositions = self.BuildViewModelBones
        end

        if (self.ShowViewModel == nil or self.ShowViewModel) then
            vm:SetColor(255,255,255,255)
        else
            // we set the alpha to 1 instead of 0 because else ViewModelDrawn stops being called
            vm:SetColor(255,255,255,1)
        end

        if (!self.vRenderOrder) then

            // we build a render order because sprites need to be drawn after models
            self.vRenderOrder = {}

            for k, v in pairs( self.VElements ) do
                if (v.type == "Model") then
                    table.insert(self.vRenderOrder, 1, k)
                elseif (v.type == "Sprite" or v.type == "Quad") then
                    table.insert(self.vRenderOrder, k)
                end
            end

        end

        for k, name in ipairs( self.vRenderOrder ) do

            local v = self.VElements[name]
            if (!v) then self.vRenderOrder = nil break end

            local model = v.modelEnt
            local sprite = v.spriteMaterial

            if (!v.bone) then continue end
            local bone = vm:LookupBone(v.bone)
            if (!bone) then continue end

            local pos, ang = Vector(0,0,0), Angle(0,0,0)
            local m = vm:GetBoneMatrix(bone)
            if (m) then
                pos, ang = m:GetTranslation(), m:GetAngle()
            end

            if (self.ViewModelFlip) then
                ang.r = -ang.r // Fixes mirrored models
            end

            if (v.type == "Model" and ValidEntity(model)) then

                model:SetPos(pos + ang:Forward() * v.pos.x + ang:Right() * v.pos.y + ang:Up() * v.pos.z )
                ang:RotateAroundAxis(ang:Up(), v.angle.y)
                ang:RotateAroundAxis(ang:Right(), v.angle.p)
                ang:RotateAroundAxis(ang:Forward(), v.angle.r)

                model:SetAngles(ang)
                model:SetModelScale(v.size)

                if (v.material == "") then
                    model:SetMaterial("")
                elseif (model:GetMaterial() != v.material) then
                    model:SetMaterial( v.material )
                end

                if (v.skin and v.skin != model:GetSkin()) then
                    model:SetSkin(v.skin)
                end

                if (v.bodygroup) then
                    for k, v in pairs( v.bodygroup ) do
                        if (model:GetBodygroup(k) != v) then
                            model:SetBodygroup(k, v)
                        end
                    end
                end

                if (v.surpresslightning) then
                    render.SuppressEngineLighting(true)
                end

                render.SetColorModulation(v.color.r/255, v.color.g/255, v.color.b/255)
                render.SetBlend(v.color.a/255)
                model:DrawModel()
                render.SetBlend(1)
                render.SetColorModulation(1, 1, 1)

                if (v.surpresslightning) then
                    render.SuppressEngineLighting(false)
                end

            elseif (v.type == "Sprite" and sprite) then

                local drawpos = pos + ang:Forward() * v.pos.x + ang:Right() * v.pos.y + ang:Up() * v.pos.z
                render.SetMaterial(sprite)
                render.DrawSprite(drawpos, v.size.x, v.size.y, v.color)

            elseif (v.type == "Quad" and v.draw_func) then

                local drawpos = pos + ang:Forward() * v.pos.x + ang:Right() * v.pos.y + ang:Up() * v.pos.z
                ang:RotateAroundAxis(ang:Up(), v.angle.y)
                ang:RotateAroundAxis(ang:Right(), v.angle.p)
                ang:RotateAroundAxis(ang:Forward(), v.angle.r)

                cam.Start3D2D(drawpos, ang, v.size)
                    v.draw_func( self )
                cam.End3D2D()

            end

        end

    end

    SWEP.wRenderOrder = nil
    function SWEP:DrawWorldModel()

        if (self.ShowWorldModel == nil or self.ShowWorldModel) then
            self:DrawModel()
        end

        if (!self.WElements) then return end

        if (!self.wRenderOrder) then

            self.wRenderOrder = {}

            for k, v in pairs( self.WElements ) do
                if (v.type == "Model") then
                    table.insert(self.wRenderOrder, 1, k)
                elseif (v.type == "Sprite" or v.type == "Quad") then
                    table.insert(self.wRenderOrder, k)
                end
            end

        end

        local opos, oang = self:GetPos(), self:GetAngles()
        local bone_ent

        if (ValidEntity(self.Owner)) then
            bone_ent = self.Owner
        else
            // when the weapon is dropped
            bone_ent = self
        end

        local bone = bone_ent:LookupBone("ValveBiped.Bip01_R_Hand")
        if (bone) then
            local m = bone_ent:GetBoneMatrix(bone)
            if (m) then
                opos, oang = m:GetTranslation(), m:GetAngle()
            end
        end

        for k, name in pairs( self.wRenderOrder ) do

            local v = self.WElements[name]
            if (!v) then self.wRenderOrder = nil break end

            local model = v.modelEnt
            local sprite = v.spriteMaterial

            local pos, ang = Vector(opos.x, opos.y, opos.z), Angle(oang.p, oang.y, oang.r)

            if (v.type == "Model" and ValidEntity(model)) then

                model:SetPos(pos + ang:Forward() * v.pos.x + ang:Right() * v.pos.y + ang:Up() * v.pos.z )
                ang:RotateAroundAxis(ang:Up(), v.angle.y)
                ang:RotateAroundAxis(ang:Right(), v.angle.p)
                ang:RotateAroundAxis(ang:Forward(), v.angle.r)

                model:SetAngles(ang)
                model:SetModelScale(v.size)

                if (v.material == "") then
                    model:SetMaterial("")
                elseif (model:GetMaterial() != v.material) then
                    model:SetMaterial( v.material )
                end

                if (v.skin and v.skin != model:GetSkin()) then
                    model:SetSkin(v.skin)
                end

                if (v.bodygroup) then
                    for k, v in pairs( v.bodygroup ) do
                        if (model:GetBodygroup(k) != v) then
                            model:SetBodygroup(k, v)
                        end
                    end
                end

                if (v.surpresslightning) then
                    render.SuppressEngineLighting(true)
                end

                render.SetColorModulation(v.color.r/255, v.color.g/255, v.color.b/255)
                render.SetBlend(v.color.a/255)
                model:DrawModel()
                render.SetBlend(1)
                render.SetColorModulation(1, 1, 1)

                if (v.surpresslightning) then
                    render.SuppressEngineLighting(false)
                end

            elseif (v.type == "Sprite" and sprite) then

                local drawpos = pos + ang:Forward() * v.pos.x + ang:Right() * v.pos.y + ang:Up() * v.pos.z
                render.SetMaterial(sprite)
                render.DrawSprite(drawpos, v.size.x, v.size.y, v.color)

            elseif (v.type == "Quad" and v.draw_func) then

                local drawpos = pos + ang:Forward() * v.pos.x + ang:Right() * v.pos.y + ang:Up() * v.pos.z
                ang:RotateAroundAxis(ang:Up(), v.angle.y)
                ang:RotateAroundAxis(ang:Right(), v.angle.p)
                ang:RotateAroundAxis(ang:Forward(), v.angle.r)

                cam.Start3D2D(drawpos, ang, v.size)
                    v.draw_func( self )
                cam.End3D2D()

            end

        end

    end

    function SWEP:CreateModels( tab )

        if (!tab) then return end

        // Create the clientside models here because Garry says we can't do it in the render hook
        for k, v in pairs( tab ) do
            if (v.type == "Model" and v.model and v.model != "" and (!ValidEntity(v.modelEnt) or v.createdModel != v.model) and
                    string.find(v.model, ".mdl") and file.Exists ("../"..v.model) ) then

                v.modelEnt = ClientsideModel(v.model, RENDER_GROUP_VIEW_MODEL_OPAQUE)
                if (ValidEntity(v.modelEnt)) then
                    v.modelEnt:SetPos(self:GetPos())
                    v.modelEnt:SetAngles(self:GetAngles())
                    v.modelEnt:SetParent(self)
                    v.modelEnt:SetNoDraw(true)
                    v.createdModel = v.model
                else
                    v.modelEnt = nil
                end

            elseif (v.type == "Sprite" and v.sprite and v.sprite != "" and (!v.spriteMaterial or v.createdSprite != v.sprite)
                and file.Exists ("../materials/"..v.sprite..".vmt")) then

                local name = v.sprite.."-"
                local params = { ["$basetexture"] = v.sprite }
                // make sure we create a unique name based on the selected options
                local tocheck = { "nocull", "additive", "vertexalpha", "vertexcolor", "ignorez" }
                for i, j in pairs( tocheck ) do
                    if (v[j]) then
                        params["$"..j] = 1
                        name = name.."1"
                    else
                        name = name.."0"
                    end
                end

                v.createdSprite = v.sprite
                v.spriteMaterial = CreateMaterial(name,"UnlitGeneric",params)

            end
        end

    end

    function SWEP:RemoveModels()
        if (self.VElements) then
            for k, v in pairs( self.VElements ) do
                if (ValidEntity( v.modelEnt )) then v.modelEnt:Remove() end
            end
        end
        if (self.WElements) then
            for k, v in pairs( self.WElements ) do
                if (ValidEntity( v.modelEnt )) then v.modelEnt:Remove() end
            end
        end
        self.VElements = nil
        self.WElements = nil
    end

end