diff --git a/src/lsystem/engine/Element.java b/src/lsystem/engine/Element.java
index a1941cf..1aed8ab 100644
--- a/src/lsystem/engine/Element.java
+++ b/src/lsystem/engine/Element.java
@@ -1,13 +1,13 @@
 package lsystem.engine;
 
-import java.util.LinkedList;
+import java.util.ArrayList;
 
 public class Element {
 
     public final ElementProperties property;
     public final Element parent;
     public final float[] rotation;
-    public final LinkedList<Element> children = new LinkedList<>();
+    public final ArrayList<Element> children = new ArrayList<>();
 
     public Element(ElementProperties property, Element parent) {
         this(property, parent, new float[]{0f, 0f, 0f});
diff --git a/src/lsystem/engine/Parser.java b/src/lsystem/engine/Parser.java
index d0987ae..2992737 100644
--- a/src/lsystem/engine/Parser.java
+++ b/src/lsystem/engine/Parser.java
@@ -92,7 +92,7 @@ public class Parser {
     }
 
     // TODO: 03/03/2021 to finish
-    public static Element parse(String word) {
+    public static Element parse(String word) throws NumberFormatException {
         char[] numbers = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '.', '+', '-'};
         Element root = null;
         Element workingElement = null;
diff --git a/src/lsystem/screen/AbstractCanvas.java b/src/lsystem/screen/AbstractCanvas.java
index 0c3917d..d3c13e7 100644
--- a/src/lsystem/screen/AbstractCanvas.java
+++ b/src/lsystem/screen/AbstractCanvas.java
@@ -65,7 +65,7 @@ public abstract class AbstractCanvas {
         return lSystem;
     }
 
-    public void setLSystem(String axiom, List<Pair<String, String>> rules, int iterations) {
+    public void setLSystem(String axiom, List<Pair<String, String>> rules, int iterations) throws NumberFormatException {
         parsedState = State.LOAD;
         this.lSystem = Parser.parse(Rewrite.rewrite(axiom, rules, iterations));
         parsedState = State.FINISH_OR_NULL;
diff --git a/src/lsystem/screen/gl3d/GLEventListener.java b/src/lsystem/screen/gl3d/GLEventListener.java
index 6292ab1..d15efe5 100644
--- a/src/lsystem/screen/gl3d/GLEventListener.java
+++ b/src/lsystem/screen/gl3d/GLEventListener.java
@@ -5,10 +5,6 @@ import com.jogamp.opengl.GLAutoDrawable;
 import com.jogamp.opengl.glu.GLU;
 import com.jogamp.opengl.util.gl2.GLUT;
 import lsystem.engine.Element;
-import lsystem.utils.Pair;
-
-import java.util.LinkedList;
-import java.util.Random;
 
 public class GLEventListener implements com.jogamp.opengl.GLEventListener {
 
@@ -19,7 +15,6 @@ public class GLEventListener implements com.jogamp.opengl.GLEventListener {
     private final float[] light_0_position = {1000f, 1000f, 1000f, 1f};
 
     private final float[] material_specular = {0.8f, 0.8f, 0.8f, 0.8f};
-    private final LinkedList<Pair<Integer, Integer>> prismPosition = new LinkedList<>();
 
     private final GLU glu;
     private final GLUT glut;
@@ -52,14 +47,6 @@ public class GLEventListener implements com.jogamp.opengl.GLEventListener {
 
         gl.glDepthFunc(GL2.GL_LEQUAL);
         gl.glHint(GL2.GL_PERSPECTIVE_CORRECTION_HINT, GL2.GL_NICEST);
-        for(int i = -50; i < 51; ++i) {
-            for(int j = -50; j < 51; ++j) {
-                if(new Random().nextFloat() < 0.05) {
-                    prismPosition.add(new Pair<>(i, j));
-                }
-            }
-        }
-        System.out.println(prismPosition.size() * 8);
         new Thread(() -> {
             while (canvas.frame.isVisible()) {
                 try {
@@ -90,6 +77,7 @@ public class GLEventListener implements com.jogamp.opengl.GLEventListener {
         glu.gluLookAt(canvas.camera[0], canvas.camera[1], canvas.camera[2], canvas.camera[0], canvas.camera[1], canvas.camera[2] - 1, 0f, 1f, 0f);
         gl.glPushMatrix();
         gl.glRotatef(90f, -1f, 0f, 0f);
+
         displayLSystem(gl, glut, canvas.getLSystem());
         gl.glPopMatrix();
 
@@ -105,9 +93,7 @@ public class GLEventListener implements com.jogamp.opengl.GLEventListener {
         gl.glRotatef(element.rotation[1]  * 360, 0f, 1f, 0f);
         gl.glRotatef((element.rotation[0] + element.rotation[1])  * 360, 0f, 0f, 1f);
         gl.glTranslated(-Math.sin(element.rotation[0]), -Math.sin(element.rotation[1]), -Math.sin(element.rotation[0] + element.rotation[1]));
-        gl.glBegin(GL2.GL_LINES);
-        glut.glutSolidCylinder(0.25f, 1f, 20, 20);
-        gl.glEnd();
+        glut.glutSolidCylinder(0.25f, 1f, 10, 10);
         gl.glTranslatef(0f, 0f, 1f);
         for(Element child : element.children) {
             displayLSystem(gl, glut, child);
diff --git a/src/lsystem/screen/main/Listener.java b/src/lsystem/screen/main/Listener.java
index d0b3008..d37e9a4 100644
--- a/src/lsystem/screen/main/Listener.java
+++ b/src/lsystem/screen/main/Listener.java
@@ -59,8 +59,13 @@ public class Listener implements ActionListener, KeyListener {
                     openDialog("Vos règles ou votre axiome ne sont pas correctement écrites, veuillez recommencer");
                 } else {
                     parserThread = new Thread(() -> {
-                        Main.joglFrame.setLSystem(axiom, parser.parseRules(), tab.getNbIterations());
-                        Main.joglFrame.setVisible(true);
+                        try {
+                            Main.joglFrame.setLSystem(axiom, parser.parseRules(), tab.getNbIterations());
+                            Main.joglFrame.setVisible(true);
+                        } catch (NumberFormatException err) {
+                            Main.joglFrame.parsedState = AbstractCanvas.State.FINISH_OR_NULL;
+                            openDialog("Une erreur de type " + err.getClass().getSimpleName() + " est survenue lors de l'execution du parser: " + err.getMessage());
+                        }
                     });
                     parserThread.start();
                 }