app.py

from flask import Flask, render_template, request, redirect, url_for, session, make_response, send_from_directory # Import the redirect function
from werkzeug.utils import secure_filename
import os
import ifcopenshell
import ifcopenshell.geom
import georeference_ifc
import re
import pyproj
from pyproj import Transformer
import pint
import numpy as np
import math
from scipy.optimize import leastsq
import pandas as pd
import json
from shapely.geometry import Polygon, mapping
import ifcopenshell.util.placement
import subprocess
import time


app = Flask(__name__, static_url_path='/static', static_folder='static')
app.secret_key = '88746898'
app.config['UPLOAD_FOLDER'] = 'uploads'
ALLOWED_EXTENSIONS = {'ifc'}  # Define allowed file extensions as a set

# Function to check if a filename has an allowed extension
def allowed_file(filename):
    return '.' in filename and filename.rsplit('.', 1)[1].lower() in ALLOWED_EXTENSIONS

def georef(ifc_file):
    geo = False
    #check ifc version
    version = ifc_file.schema
    message = f"IFC version: {version}\n"
    # Check the file is georefed or not
    mapconversion = None
    crs = None

    if ifc_file.schema[:4] == 'IFC4':
        project = ifc_file.by_type("IfcProject")[0]
        for c in (m for c in project.RepresentationContexts for m in c.HasCoordinateOperation):
            mapconversion = c
            crs = c.TargetCRS
        if mapconversion is not None:
            message += "IFC file is georeferenced.\n"
            geo = True
    if ifc_file.schema == 'IFC2X3':
        site = ifc_file.by_type("IfcSite")[0]
        psets = ifcopenshell.util.element.get_psets(site)
        if 'ePSet_MapConversion' in psets.keys() and 'ePSet_ProjectedCRS' in psets.keys():
            message += "IFC file is georeferenced.\n"
            geo = True
    return message , geo
        
def infoExt(filename , epsgCode):
    ureg = pint.UnitRegistry()
    ifc_file = fileOpener(filename)
    #check ifc version
    version = ifc_file.schema
    messages = [('IFC version', version)]
    ifc_site = ifc_file.by_type("IfcSite")


    #Find Longtitude and Latitude
    RLat = ifc_site[0].RefLatitude
    RLon = ifc_site[0].RefLongitude
    RElev = ifc_site[0].RefElevation
    if RLat is not None and RLon is not None:
        x0= (float(RLat[0]) + float(RLat[1])/60 + float(RLat[2]+RLat[3]/1000000)/(60*60))
        y0= (float(RLon[0]) + float(RLon[1])/60 + float(RLon[2]+RLon[3]/1000000)/(60*60))
        session['Refl'] = True
        if hasattr(ifc_file.by_type("IfcSite")[0], "ObjectPlacement") and ifc_file.by_type("IfcSite")[0].ObjectPlacement.is_a("IfcLocalPlacement"):
            local_placement = ifc_file.by_type("IfcSite")[0].ObjectPlacement.RelativePlacement
                # Check if the local placement is an IfcAxis2Placement3D
            if local_placement.is_a("IfcAxis2Placement3D"):
                local_origin = local_placement.Location.Coordinates
                bx,by,bz= local_origin
                messages.append(('IFC Local Origin', local_origin))
            else:
                    errorMessage = "Local placement is not IfcAxis2Placement3D."
                    return messages, errorMessage
        else:
                errorMessage = "IfcSite does not have a local placement."
                return messages, errorMessage
    else:
        session['Refl'] = False
        messages.append(('RefLatitude or RefLongitude', 'Not available'))
    Refl = session.get('Refl')
    crs = None
    if ifc_file.schema[:4] != 'IFC4' and ifc_file.schema != 'IFC2X3':
        errorMessage = "IFC2X3, IFC4, and newer versions are supported.\n"
        return messages, errorMessage

    bx,by,bz = 0,0,0
    # Find local origin

                
    # Target CRS unit name
    try: 
        crs = pyproj.CRS.from_epsg(int(epsgCode))
    except:
        errorMessage = "CRS is not available."
        return messages, errorMessage


    crsunit = crs.axis_info[0].unit_name

    if crs.is_projected:
        messages.append(('Target CRS Type', 'Projected'))
        messages.append(('Target CRS EPSG', epsgCode))

    else:
        errorMessage = "CRS is not projected (geographic)."
        return messages, errorMessage
    target_epsg = "EPSG:"+str(epsgCode)
    transformer = Transformer.from_crs("EPSG:4326", target_epsg)
    # IFC length unit name
    ifc_units = ifc_file.by_type("IfcUnitAssignment")[0].Units
    for ifc_unit in ifc_units:
        if ifc_unit.is_a("IfcSIUnit") and ifc_unit.UnitType == "LENGTHUNIT":
            if ifc_unit.Prefix is not None:
                ifcunit = ifc_unit.Prefix + ifc_unit.Name
            else:
                ifcunit = ifc_unit.Name
    try: 
        quantity = unitmapper(ifcunit)
        ifcmeter = quantity.to(ureg.meter).magnitude
    except:
        ifcmeter = None
    # try:
    #     if ifcunit in unit_mapping:
    #         quantity = 1 * unit_mapping[ifcunit]
    #         ifcmeter = quantity.to(ureg.meter).magnitude
    #     else:
    #         ifcmeter = None
    # except:
    #     ifcmeter = None
    try: 
        quantity = unitmapper(crsunit)
        crsmeter = quantity.to(ureg.meter).magnitude
    except:
        crsmeter = None

    # try:
    #     if crsunit in unit_mapping:
    #         quantity = 1 * unit_mapping[crsunit]
    #         crsmeter = quantity.to(ureg.meter).magnitude
    #     else:
    #         crsmeter = None
    # except:
    #     crsmeter = None

    if crsmeter is not None and ifcmeter is not None:
        coeff= ifcmeter/crsmeter
    else:
        errorMessage = "IFC/Map unit error"
        return messages, errorMessage
    if Refl:
        messages.append(("Reference Longitude",y0))
        messages.append(("Reference Latitude",x0))
        messages.append(("Reference Elevation",RElev))

    messages.append(("Target CRS Unit",str.lower(crsunit)))

    session['mapunit'] = str.lower(crsunit)

    if ifcunit:
        unit_name = ifcunit
        messages.append(("IFC Unit",str.lower(unit_name)))
        session['ifcunit'] = str.lower(unit_name)

    else:
        errorMessage = "No length unit found in the IFC file."
        return messages, errorMessage
    messages.append(("Unit Conversion Ratio",coeff))
    errorMessage = ""
    session['coeff'] = coeff
    if Refl:
        x1,y1,z1 = transformer.transform(x0,y0,RElev)
        x2= x1*coeff
        y2= y1*coeff
        session['xt'] = x1
        session['yt'] = y1
        session['z1'] = z1
        session['Longitude'] = y0
        session['Latitude'] = x0


    return messages, errorMessage

def unitmapper(value):
    ureg = pint.UnitRegistry()
    unit_mapping = {
    "METRE": ureg.meter,
    "METER": ureg.meter,
    "CENTIMETRE": ureg.centimeter,
    "CENTIMETER": ureg.centimeter,
    "MILLIMETRE": ureg.millimeter,
    "MILLIMETER": ureg.millimeter,
    "INCH": ureg.inch,
    "FOOT": ureg.foot,
    "YARD": ureg.yard,
    "MILE": ureg.mile,
    "NAUTICAL_MILE": ureg.nautical_mile,
    "metre": ureg.meter,
    "meter": ureg.meter,
    "centimeter": ureg.centimeter,
    "centimetre": ureg.centimeter,
    "millimeter": ureg.millimeter,
    "millimetre": ureg.millimeter,
    "inch": ureg.inch,
    "foot": ureg.foot,
    "yard": ureg.yard,
    "mile": ureg.mile,
    "nautical_mile": ureg.nautical_mile,
    # Add more mappings as needed
    }
    if value in unit_mapping:
            return  1 * unit_mapping[value]
    return

@app.route('/')
def index():
    return render_template('upload.html')

@app.route('/upload', methods=['POST'])
def upload_file():
    if 'file' not in request.files:
        return "No file part"
    file = request.files['file']
    if file.filename == '':
        return "No selected file"
    if file and allowed_file(file.filename):  # Check if the file extension is allowed
        filename = secure_filename(file.filename)
        file.save(os.path.join(app.config['UPLOAD_FOLDER'], filename))
        ifc_file = fileOpener(filename)

        message, geo = georef(ifc_file)
        if geo:
            IfcMapConversion, IfcProjectedCRS = georeference_ifc.get_mapconversion_crs(ifc_file=ifc_file)
            df = pd.DataFrame(list(IfcProjectedCRS.__dict__.items()), columns= ['property', 'value'])
            dg = pd.DataFrame(list(IfcMapConversion.__dict__.items()), columns= ['property', 'value'])
            html_table_f = df.to_html()
            html_table_g = dg.to_html()
            IfcMapConversion, IfcProjectedCRS = georeference_ifc.get_mapconversion_crs(ifc_file=ifc_file)
            target = IfcProjectedCRS.Name.split(':')
            epsg = int(target[1])
            message2 = infoExt(filename,epsg)
            coeff = session.get('coeff')
            if coeff is None:
                return render_template('result.html', filename=filename, table_f=html_table_f, table_g=html_table_g, message=message2)

            if int(coeff)!=1 and IfcMapConversion.Scale is None:
                message += "There is a conflict between Scale factor and unit conversion. (Yet to be decided by buildingSmart.)"
                session['scaleError']=True
                return render_template('result.html', filename=filename, table_f=html_table_f, table_g=html_table_g, message=message)
            if int(coeff)!=1 and int(IfcMapConversion.Scale) == 1:
                message += "There is a conflict between Scale factor and unit conversion. (Yet to be decided by buildingSmart.)"
                session['scaleError']=True
            return render_template('result.html', filename=filename, table_f=html_table_f, table_g=html_table_g, message=message)
        
        return redirect(url_for('convert_crs', filename=filename))  # Redirect to EPSG code input page
    else:
        return render_template('upload.html', error_message="Invalid file format. Please upload a .ifc file.")

@app.route('/devs', methods=['GET', 'POST'])
def devs_upload():
    if request.method == 'POST':
        if 'file' not in request.files:
            return "No file part"

        file = request.files['file']

        if file.filename == '':
            return "No selected file"

        if file and allowed_file(file.filename):
            filename = secure_filename(file.filename)
            file.save(os.path.join(app.config['UPLOAD_FOLDER'], filename))
            ifc_file = fileOpener(filename)

            # Check if the IFC file is georeferenced
            message, geo = georef(ifc_file)

            if geo:
                IfcMapConversion, IfcProjectedCRS = georeference_ifc.get_mapconversion_crs(ifc_file=ifc_file)
                dg = pd.DataFrame(list(IfcMapConversion.__dict__.items()), columns= ['property', 'value'])
                message += "IfcMapconversion:\n\n" + dg.to_string()
                return f"Filename: {filename}\nGeoreferenced: YES\n{message}"
            else:
                message += "For georeferencing the IFC file, please visit the following address in a web browser:\nhttps://ifcgref.bk.tudelft.nl"
                return f"Filename: {filename}\nGeoreferenced: NO\n{message}"
                
@app.route('/convert/<filename>', methods=['GET', 'POST'])
def convert_crs(filename):
    if request.method == 'POST':
        try:
            epsg_code = int(request.form['epsg_code'])
        except ValueError:
            message = "Invalid EPSG code. Please enter a valid integer."
            return render_template('convert.html', filename=filename, message=message)
        session['target_epsg'] = epsg_code
       # Call the infoExt function and unpack the results
        messages, error = infoExt(filename, epsg_code)
        if error == "":
            # Pass x2, y2, and z1 to the survey_points route
            return redirect(url_for('survey_points', filename=filename))
        return render_template('convert.html', filename=filename, message=error)

    return render_template('convert.html', filename=filename)

@app.route('/survey/<filename>', methods=['GET', 'POST'])
def survey_points(filename):
    epsg_code = session.get('target_epsg')
    messages, error = infoExt(filename, epsg_code)
    ifcunit = session.get('ifcunit')
    mapunit = session.get('mapunit')
    Refl = session.get('Refl')
    if request.method == 'POST':
        box_number = request.form.get('boxNumber')
        if box_number == '3':
            session['Refl'] = False
            Refl = False
    if Refl:
        messages , error = local_trans(filename,messages)
        Num = []
        if request.method == 'POST':
            try:
                Num = int(request.form['Num'])
                if Num < 0:
                    error += "Please enter zero or a positive integer."
                    return render_template('survey.html', filename=filename, messages=messages, error=error)
            except ValueError:
                error += "Please enter zero or a positive integer."
                return render_template('survey.html', filename=filename, messages=messages, error=error)
            session['rows'] = Num
            if Num == 0:
                return redirect(url_for('calculate', filename=filename))
        return render_template('survey.html', filename=filename, messages=messages, Num=Num, ifcunit=ifcunit, mapunit=mapunit, error=error, Refl = Refl)
    else:
        error += '\nThe model has no surveyed or georeferenced attribute.\nYou need to provide at least one point in local and target CRS.'
        error += '\n\nAccuracy of the results improves as you provide more georeferenced points.\nWithout any additional georeferenced points, it is assumed that the model is scaled based on unit conversion and rotation is derived from TrueNorth direction (if availalble).\n'
        Num = []
        if request.method == 'POST':
            try:
                Num = int(request.form['Num'])
                if Num <= 0:
                    error += "Please enter a positive integer."
                    return render_template('survey.html', filename=filename, error=error)
            except ValueError:
                error += "Please enter a positive integer."
                return render_template('survey.html', filename=filename, error=error)
            session['rows'] = Num
        return render_template('survey.html', filename=filename, messages=messages, Num=Num, ifcunit=ifcunit, mapunit=mapunit, Refl = Refl)


def local_trans(filename , messages):
    ifc_file = fileOpener(filename)
    xt = session.get('xt')
    yt = session.get('yt')
    z1 = session.get('z1')
    bx,by,bz = 0,0,0
    error = ""
    if hasattr(ifc_file.by_type("IfcSite")[0], "ObjectPlacement") and ifc_file.by_type("IfcSite")[0].ObjectPlacement.is_a("IfcLocalPlacement"):
        local_placement = ifc_file.by_type("IfcSite")[0].ObjectPlacement.RelativePlacement
        # Check if the local placement is an IfcAxis2Placement3D
        if local_placement.is_a("IfcAxis2Placement3D"):
            local_origin = local_placement.Location.Coordinates
            bx, by, bz = map(float, local_origin)
            messages.append(("First Point Local Coordinates",str(local_origin)))
        else:
                error += "Local placement is not IfcAxis2Placement3D."
    else:
            error += "IfcSite does not have a local placement."
    session['bx'] = bx
    session['by'] = by        
    session['bz'] = bz        

    messages.append(("First Point Target coordinates" , ("(" + str(xt) + ", " + str(yt) + ", " + str(z1) + ")")))
    error += '\n\nAccuracy of the results improves as you provide more georeferenced points.\nWithout any additional georeferenced points, it is assumed that the model is scaled based on unit conversion and rotation is derived from TrueNorth direction (if available).\n'

    ifc_file = ifc_file.end_transaction()
    return messages, error

@app.route('/calc/<filename>', methods=['GET', 'POST'])
def calculate(filename):
    #if request.method == 'POST':
        # Access the form data by iterating through the rows
        coeff = session.get('coeff')
        rows = session.get('rows')
        fn = os.path.join(app.config['UPLOAD_FOLDER'], filename)
        ifc_file = fileOpener(filename)
        data_points = []
        Refl = session.get('Refl')
        if Refl:
            xt = session.get('xt')
            yt = session.get('yt')
            bx = session.get('bx')
            by = session.get('by')
            data_points.append({"X": bx, "Y": by, "X_prime": xt, "Y_prime": yt})
        #seperater
        if not Refl and rows == 1:
            Rotation_solution = 0
            S_solution = coeff
            ro = ifc_file.by_type("IfcGeometricRepresentationContext")[0].TrueNorth
            if ro is not None and ro.is_a("IfcDirection"):
                xord , xabs = round(float(ro[0][0]),6) , round(float(ro[0][1]),6)
            else:
                xord , xabs = 0 , 1
            Rotation_solution = math.atan2(xord,xabs)
            A = math.cos(Rotation_solution)
            B = math.sin(Rotation_solution)
            E_solution = float(request.form[f'x_prime{0}']) - (A*float(request.form[f'x{0}'])*coeff) + (B*float(request.form[f'y{0}'])*coeff)
            N_solution = float(request.form[f'y_prime{0}']) - (B*float(request.form[f'x{0}'])*coeff) - (A*float(request.form[f'y{0}'])*coeff)
            session['z1'] = float(request.form[f'z_prime{0}'])
            session['bz'] = float(request.form[f'z{0}'])

        #seperater
        else:
            if rows == 0:
                Rotation_solution = 0
                S_solution = coeff
                ro = ifc_file.by_type("IfcGeometricRepresentationContext")[0].TrueNorth
                if ro is not None and ro.is_a("IfcDirection"):
                    xord , xabs = round(float(ro[0][0]),6) , round(float(ro[0][1]),6)
                else:
                    xord , xabs = 0 , 1
                Rotation_solution = math.atan2(xord,xabs)
                A = math.cos(Rotation_solution)
                B = math.sin(Rotation_solution)
                E_solution = xt - (A*S_solution*bx) + (B*S_solution*by)
                N_solution = yt - (B*S_solution*bx) - (A*S_solution*by)
            else:
                for row in range(rows):
                    x = request.form[f'x{row}']
                    y = request.form[f'y{row}']
                    z = request.form[f'z{row}']
                    x_prime = request.form[f'x_prime{row}']
                    y_prime = request.form[f'y_prime{row}']
                    z_prime = request.form[f'z_prime{row}']

                    try:
                        x = float(x)
                        y = float(y)
                        z = float(z)
                        x_prime = float(x_prime)
                        y_prime = float(y_prime)
                        z_prime = float(z_prime)
                    except ValueError:
                        message = "Invalid input. Please enter only float values."
                        Num = rows
                        return render_template('survey.html', message=message, Num=Num)

                    data_points.append({"X": x, "Y": y, "X_prime": x_prime, "Y_prime": y_prime})

                def equations(variables, data_points):
                        S, Rotation, E, N = variables
                        eqs = []

                        for data in data_points:
                            X = data["X"]
                            Y = data["Y"]
                            X_prime = data["X_prime"]
                            Y_prime = data["Y_prime"]

                            eq1 = S * np.cos(Rotation) * X - S * np.sin(Rotation) * Y + E - X_prime
                            eq2 = S * np.sin(Rotation) * X + S * np.cos(Rotation) * Y + N - Y_prime
                            eqs.extend([eq1, eq2])

                        return eqs
                    # Initial guess for variables [S, Rotation, E, N]
                if Refl:
                    initial_guess = [coeff, 0, xt, yt]
                else:
                    initial_guess = [coeff,0,0,0]

                # Perform the least squares optimization for all data points
                result, _ = leastsq(equations, initial_guess, args=(data_points,))
                S_solution, Rotation_solution, E_solution, N_solution = result

        Rotation_degrees = (180 / math.pi) * Rotation_solution
        rDeg = Rotation_degrees - (360*round(Rotation_degrees/360))

        target_epsg = "EPSG:"+str(session.get('target_epsg'))
        georeference_ifc.set_mapconversion_crs(ifc_file=ifc_file,
                                        target_crs_epsg_code=target_epsg,
                                        eastings=E_solution,
                                        northings=N_solution,
                                        orthogonal_height=(session.get('z1')-(session.get('bz')*S_solution)),
                                        x_axis_abscissa=math.cos(Rotation_solution),
                                        x_axis_ordinate=math.sin(Rotation_solution),
                                        scale=S_solution)
        fn_output = re.sub('\.ifc$','_georeferenced.ifc', fn)
        ifc_file.write(fn_output)
        IfcMapConversion, IfcProjectedCRS = georeference_ifc.get_mapconversion_crs(ifc_file=ifc_file)
        df = pd.DataFrame(list(IfcProjectedCRS.__dict__.items()), columns= ['property', 'value'])
        dg = pd.DataFrame(list(IfcMapConversion.__dict__.items()), columns= ['property', 'value'])
        dg['value'] = dg['value'].astype(str)
        html_table_f = df.to_html()
        html_table_g = dg.to_html()
        return render_template('result.html', filename=filename, table_f=html_table_f, table_g=html_table_g)
    
def fileOpener(filename):
    fn = os.path.join(app.config['UPLOAD_FOLDER'], filename)
    print("Opening IFC file:", fn)  # Add this line for debugging
    try:
        ifc_file = ifcopenshell.open(fn)
        # ifc_schema = ifc_file.schema
        # ifc_site = ifc_file.by_type("IfcSite")[0]
        # ifc_unit = ifc_file.by_type("IfcUnitAssignment")[0].Units
        # ifc_geom = ifc_file.by_type("IfcGeometricRepresentationContext")[0]
        # ifc_mapconv, ifc_projcrs = georeference_ifc.get_mapconversion_crs(ifc_file=ifc_file)
        # session['ifc_schema'] = ifc_schema
        # session['ifc_site'] = pickle.dumps(ifc_site.ObjectPlacement)
        # # session['ifc_unit'] = ifc_unit
        # # session['ifc_geom'] = ifc_geom
        # # session['ifc_mapconv'] = ifc_mapconv
        # # session['ifc_projcrs'] = ifc_projcrs
        return ifc_file
    except Exception as e:
        print("Error opening IFC file:", str(e))  # Add this line for debugging
        return None

@app.route('/show/<filename>', methods=['POST'])
def visualize(filename):
    fn = os.path.join(app.config['UPLOAD_FOLDER'], filename)
    fn_output = re.sub('\.ifc$','_georeferenced.ifc', fn)
    if not os.path.exists(fn_output):
        fn_output = fn
    ifc_file = ifcopenshell.open(fn_output)
    IfcMapConversion, IfcProjectedCRS = georeference_ifc.get_mapconversion_crs(ifc_file=ifc_file)
    target = IfcProjectedCRS.Name.split(':')
    org = ifc_file.by_type('IfcProject')[0].RepresentationContexts[0].WorldCoordinateSystem.Location.Coordinates
    E = IfcMapConversion.Eastings
    N = IfcMapConversion.Northings
    S = IfcMapConversion.Scale
    if S is None:
        S = 1
    ortz = IfcMapConversion.OrthogonalHeight
    cos = IfcMapConversion.XAxisAbscissa
    if cos is None:
        cos = 1    
    sin = IfcMapConversion.XAxisOrdinate
    if sin is None:
        sin = 0
    Rotation_solution = math.atan2(sin,cos)
    A = math.cos(Rotation_solution)
    B = math.sin(Rotation_solution)        
    target_epsg = "EPSG:"+ target[1]
    transformer2 = Transformer.from_crs(target_epsg,"EPSG:4326")
    scaleError = session.get('scaleError')
    Gx , Gy = 0 , 0
    eff = session.get('coeff')
    if scaleError:
        saver = S
        S = eff
        session.pop('scaleError', None)  # Corrected line
        E=E*S
        N = N*S
        ortz= ortz*S
        xx = S * org[0]* A - S * org[1]*B + E
        yy = S * org[1]* A + S * org[1]*B + N
        z = S * org[2] + ortz
        S = saver
        Snew = S
    else:
        xx = S * org[0]* A - S * org[1]*B + E
        yy = S * org[1]* A + S * org[1]*B + N
        zz = S * org[2] + ortz
        Snew = S/eff
    if xx==0 and yy==0:
        products = ifc_file.by_type('IfcProduct')
        for product in products:
            if product.Representation:
                placement = product.ObjectPlacement
                lpMAat = ifcopenshell.util.placement.get_local_placement(placement)
                Gx , Gy = lpMAat[0][3]*eff,lpMAat[1][3]*eff
                xx = xx+Gx
                yy = yy+Gy
                break
    x2,y2 = transformer2.transform(xx,yy)
    Latitude =x2
    Longitude =y2
    projstring = pyproj.CRS(target_epsg).to_proj4()
    crs = pyproj.CRS(projstring)
    alpha_value = crs.to_dict().get('alpha', None)
    Scale_value = crs.to_dict().get('k', None)
    # if Scale_value is not None:
    #     Snew = Snew/Scale_value
    # if alpha_value is not None:
    transformer3 = Transformer.from_crs(target_epsg, "EPSG:3857", always_xy=True)
    x_3857, y_3857 = transformer3.transform(xx, yy)
    xn_3857, yn_3857 = transformer3.transform(xx+1000, yy)
    dx = -x_3857 + xn_3857
    dy = -y_3857 + yn_3857
    angle_radians = math.atan2(dy, dx)
    angle_degrees = math.degrees(angle_radians)
    Rotation_solution = Rotation_solution + angle_radians
    length = math.sqrt(dx**2 + dy**2)
    # transformer3 = Transformer.from_crs(target_epsg, "EPSG:3857", always_xy=True)
    x_3857, y_3857 = transformer3.transform(xx, yy)
    xn_3857, yn_3857 = transformer3.transform((xx+50), (yy+50))
    dx = -x_3857 + xn_3857
    dy = -y_3857 + yn_3857
    length = math.sqrt(dx**2 + dy**2)
    min_z_value = float('inf')

    for product in ifc_file.by_type('IfcProduct'):
    # Check if the product has a placement
        if product.Representation:
            placement = product.ObjectPlacement
            location = ifcopenshell.util.placement.get_local_placement(placement)
            z_value = location[2][3]*eff  # Z is usually the 3rd coordinate (0: X, 1: Y, 2: Z)            
            if z_value < min_z_value:
                min_z_value = z_value
    return render_template('view3D.html', filename=filename, Latitude=Latitude, Longitude=Longitude, Rotate=Rotation_solution, origin = org, Scale = Snew, ScaleCRS = Scale_value, Gx=Gx, Gy=Gy, LowestLevel = min_z_value)

@app.route('/download/<filename>', methods=['GET'])
def download(filename):
    # Define the path to the GeoJSON file
    fn = re.sub('\.ifc$','_georeferenced.ifc', filename)
    file_path = os.path.join(app.config['UPLOAD_FOLDER'], fn)

    # Ensure the file exists
    if os.path.exists(file_path):
        # Set the response headers to indicate a file download
        response = make_response()
        response.headers['Content-Type'] = 'application/octet-stream'
        response.headers['Content-Disposition'] = f'attachment; filename={fn}'
        
        # Read the file content and add it to the response
        with open(file_path, 'rb') as file:
            response.data = file.read()
        
        return response
    else:
        # Return a 404 error if the file doesn't exist
        return 'File not found', 404
@app.route('/templates/<path:filename>')
def temp(filename):
    return send_from_directory('templates', filename)
   
@app.route('/uploads/<path:filename>')
def ups(filename):
    return send_from_directory('uploads', filename)
   
if __name__ == '__main__':
    app.run(debug=True)