catjpeg.lua

local catjpeg = Material("catjpeg.jpg", "noclamp")
catjpeg = catjpeg:GetTexture("$basetexture")

local function GetStaticProps()
    local static_props = {}

    local map = string.format("maps/%s.bsp", game.GetMap())
    local fl = file.Open(map, "rb", "GAME")

    fl:Seek(568)

    local lump_data = {
        data = {},
        fileofs = fl:ReadLong(),
        filelen = fl:ReadLong(),
        version = fl:ReadLong(),
        fourCC = fl:Read(4),
    }

    fl:Seek(lump_data.fileofs)

    for i = 1, fl:ReadLong() do
        lump_data.data[i] = {
            id = fl:Read(4),
            flags = fl:ReadShort(),
            version = fl:ReadShort(),
            fileofs = fl:ReadLong(),
            filelen = fl:ReadLong(),
        }
    end

    for _, lump in ipairs(lump_data.data) do
        fl:Seek(lump.fileofs)

        for i = 1, fl:ReadLong() do
            local mdl = fl:Read(128)
            mdl = string.match(mdl, "^[%Z]+")

            if (mdl) then
                table.insert(static_props, mdl)
            end
        end
    end

    fl:Close()

    return static_props
end

do
    local brushes = Entity(0):GetBrushSurfaces()

    for i, surfaceinfo in ipairs(brushes) do
        if (surfaceinfo:IsWater() or surfaceinfo:IsSky()) then continue end

        local mat = surfaceinfo:GetMaterial()
        mat:SetTexture("$basetexture", catjpeg)
        mat:SetTexture("$basetexture2", catjpeg)
    end
end

do
    local props = GetStaticProps()
    local ent = ClientsideModel("error")

    for i, mdl in ipairs(props) do
        ent:SetModel(mdl)

        for _, mat in ipairs(ent:GetMaterials()) do
            mat = Material(mat)
            mat:SetTexture("$basetexture", catjpeg)
            mat:SetTexture("$basetexture2", catjpeg)
        end
    end

    ent:Remove()
end