diff --git a/angular.json b/angular.json
index 32b9018..14cd9ca 100644
--- a/angular.json
+++ b/angular.json
@@ -55,6 +55,7 @@
               }
             ],
             "styles": [
+              "./node_modules/@angular/material/prebuilt-themes/indigo-pink.css",
               "src/styles.scss",
               "node_modules/leaflet/dist/leaflet.css"
             ],
@@ -122,6 +123,7 @@
               "src/assets"
             ],
             "styles": [
+              "./node_modules/@angular/material/prebuilt-themes/indigo-pink.css",
               "src/styles.scss"
             ],
             "scripts": []
@@ -159,4 +161,4 @@
   "cli": {
     "analytics": false
   }
-}
+}
\ No newline at end of file
diff --git a/package.json b/package.json
index c633f94..b548676 100644
--- a/package.json
+++ b/package.json
@@ -59,11 +59,13 @@
   "private": true,
   "dependencies": {
     "@angular/animations": "~9.1.1",
+    "@angular/cdk": "9.2.4",
     "@angular/common": "~9.1.1",
     "@angular/compiler": "~9.1.1",
     "@angular/core": "~9.1.1",
     "@angular/forms": "~9.1.1",
     "@angular/localize": "^9.1.1",
+    "@angular/material": "9.2.4",
     "@angular/platform-browser": "~9.1.1",
     "@angular/platform-browser-dynamic": "~9.1.1",
     "@angular/router": "~9.1.1",
diff --git a/src/app/app.module.ts b/src/app/app.module.ts
index 1ca00ea..bc1081b 100644
--- a/src/app/app.module.ts
+++ b/src/app/app.module.ts
@@ -1,27 +1,29 @@
-import { BrowserModule } from '@angular/platform-browser';
-import { NgModule } from '@angular/core';
+import {BrowserModule} from '@angular/platform-browser';
+import {NgModule} from '@angular/core';
 
-import { AppRoutingModule } from './app-routing.module';
-import { AppComponent } from './app.component';
-import { NgbModule } from '@ng-bootstrap/ng-bootstrap';
-import { LoadConfigComponent } from './load-config/load-config.component';
-import { ExportConfigComponent } from './export-config/export-config.component';
-import { FontAwesomeModule, FaIconLibrary } from '@fortawesome/angular-fontawesome';
-import { HashLocationStrategy, LocationStrategy } from '@angular/common';
+import {AppRoutingModule} from './app-routing.module';
+import {AppComponent} from './app.component';
+import {NgbModule} from '@ng-bootstrap/ng-bootstrap';
+import {LoadConfigComponent} from './load-config/load-config.component';
+import {ExportConfigComponent} from './export-config/export-config.component';
+import {FaIconLibrary, FontAwesomeModule} from '@fortawesome/angular-fontawesome';
+import {HashLocationStrategy, LocationStrategy} from '@angular/common';
 
-import { FormsModule } from '@angular/forms';
-import { LoadConfigCsvComponent } from './load-config-csv/load-config-csv.component';
-import { LoadConfigTxtComponent } from './load-config-txt/load-config-txt.component';
-import { LoadConfigEmptyComponent } from './load-config-empty/load-config-empty.component';
-import { LicenseInfoComponent } from './license-info/license-info.component';
-import { GcpsMapComponent } from './gcps-map/gcps-map.component';
-import { ImagesTaggerComponent } from './images-tagger/images-tagger.component';
-import { LeafletModule } from '@asymmetrik/ngx-leaflet';
-import { fas } from '@fortawesome/free-solid-svg-icons';
-import { far } from '@fortawesome/free-regular-svg-icons';
-import { SmartimageComponent } from './smartimage/smartimage.component';
-import { ConfirmDialogComponent } from './confirm-dialog/confirm-dialog.component';
-import { NgOpenCVModule, OpenCVOptions } from "ng-open-cv";
+import {FormsModule} from '@angular/forms';
+import {LoadConfigCsvComponent} from './load-config-csv/load-config-csv.component';
+import {LoadConfigTxtComponent} from './load-config-txt/load-config-txt.component';
+import {LoadConfigEmptyComponent} from './load-config-empty/load-config-empty.component';
+import {LicenseInfoComponent} from './license-info/license-info.component';
+import {GcpsMapComponent} from './gcps-map/gcps-map.component';
+import {ImagesTaggerComponent} from './images-tagger/images-tagger.component';
+import {LeafletModule} from '@asymmetrik/ngx-leaflet';
+import {fas} from '@fortawesome/free-solid-svg-icons';
+import {far} from '@fortawesome/free-regular-svg-icons';
+import {SmartimageComponent} from './smartimage/smartimage.component';
+import {ConfirmDialogComponent} from './confirm-dialog/confirm-dialog.component';
+import {NgOpenCVModule, OpenCVOptions} from 'ng-open-cv';
+import {MatSlideToggleModule} from '@angular/material/slide-toggle';
+import { BrowserAnimationsModule } from '@angular/platform-browser/animations';
 
 const openCVConfig: OpenCVOptions = {
     scriptUrl: `assets/opencv/opencv.js`,
@@ -51,6 +53,8 @@ const openCVConfig: OpenCVOptions = {
         FormsModule,
         LeafletModule.forRoot(),
         NgOpenCVModule.forRoot(openCVConfig),
+        MatSlideToggleModule,
+        BrowserAnimationsModule
     ],
     providers: [
         {
diff --git a/src/app/export-config/export-config.component.html b/src/app/export-config/export-config.component.html
index 47c83a2..2e723df 100644
--- a/src/app/export-config/export-config.component.html
+++ b/src/app/export-config/export-config.component.html
@@ -13,7 +13,7 @@
                 <tr>
                     <th>X</th>
                     <th>Y</th>
-                    <th>Z</th>
+                    <th>Z <mat-slide-toggle [(ngModel)]="replaceNanZ">NaN -> 0</mat-slide-toggle></th>
                     <th>ImageX</th>
                     <th>ImageY</th>
                     <th>Filename</th>
@@ -32,7 +32,7 @@
                         {{ imgGcp.geoY }}
                     </td>
                     <td>
-                        {{ imgGcp.geoZ }}
+                        {{ (imgGcp.geoZ !== imgGcp.geoZ) && replaceNanZ ? 0 : imgGcp.geoZ }}
                     </td>
                     <td *ngIf="!storage.getLicense().demo">
                         {{ imgGcp.imX }}
@@ -60,11 +60,11 @@
         </table>
     </div>
 </div>
-<div class="fixed-bottom bg-white d-flex justify-content-between align-items-center">    
+<div class="fixed-bottom bg-white d-flex justify-content-between align-items-center">
     <button class="btn btn-primary ml-3 my-3" (click)="back()">
         <fa-icon icon="long-arrow-alt-left" class="mr-2"></fa-icon>Back
     </button>
     <button class="btn btn-primary mr-3 my-3" (click)="exportTxt()">
         <fa-icon icon="download" class="mr-2"></fa-icon>Download gcp_list.txt
     </button>
-</div>
\ No newline at end of file
+</div>
diff --git a/src/app/export-config/export-config.component.ts b/src/app/export-config/export-config.component.ts
index 92f872a..9bac292 100644
--- a/src/app/export-config/export-config.component.ts
+++ b/src/app/export-config/export-config.component.ts
@@ -1,9 +1,8 @@
-import { Component, OnInit } from '@angular/core';
-import { Router } from '@angular/router';
-import { StorageService } from '../storage.service';
-import { ImageGcp, GCP, Projection, GcpsUtilsService } from '../gcps-utils.service';
+import {Component, OnInit} from '@angular/core';
+import {Router} from '@angular/router';
+import {StorageService} from '../storage.service';
+import {GCP, GcpsUtilsService, ImageGcp, Projection} from '../gcps-utils.service';
 import * as FileSaver from 'file-saver';
-import { stringify } from 'querystring';
 
 @Component({
     selector: 'app-export-config',
@@ -16,6 +15,7 @@ export class ExportConfigComponent implements OnInit {
     public gcps: GCP[];
     public projection: Projection;
     public extras: string[];
+    public replaceNanZ: boolean;
 
     constructor(private router: Router, public storage: StorageService, private utils: GcpsUtilsService) {
 
@@ -33,6 +33,7 @@ export class ExportConfigComponent implements OnInit {
         this.gcps = storage.gcps;
         this.projection = storage.projection;
         this.extras = utils.generateExtrasNames(this.imageGcps);
+        this.replaceNanZ = false;
     }
 
     ngOnInit(): void {
@@ -47,7 +48,8 @@ export class ExportConfigComponent implements OnInit {
         let content = this.projection.str + '\n';
 
         for (const img of this.imageGcps) {
-            content += `${img.geoX}\t${img.geoY}\t${img.geoZ}\t${img.imX}\t${img.imY}\t${img.imgName}\t${img.gcpName}\t${img.extras.join('\t')}`.trim() + '\n';
+            const geoZ = (img.geoZ !== img.geoZ) && this.replaceNanZ ? 0 : img.geoZ;
+            content += `${img.geoX}\t${img.geoY}\t${geoZ}\t${img.imX}\t${img.imY}\t${img.imgName}\t${img.gcpName}\t${img.extras.join('\t')}`.trim() + '\n';
         }
 
         return content;
diff --git a/src/index.html b/src/index.html
index 8493f1b..a40e501 100644
--- a/src/index.html
+++ b/src/index.html
@@ -10,6 +10,8 @@
     <link rel="icon" type="image/png" sizes="32x32" href="assets/favicons/favicon-32x32.png">
     <link rel="icon" type="image/png" sizes="16x16" href="assets/favicons/favicon-16x16.png">
     <link rel="manifest" href="assets/favicons/site.webmanifest">
+    <link href="https://fonts.googleapis.com/css?family=Roboto:300,400,500&display=swap" rel="stylesheet">
+    <link href="https://fonts.googleapis.com/icon?family=Material+Icons" rel="stylesheet">
 </head>
 
 <body>