diff --git a/Pilz.Drawing.Drawing3D.OpenGLRenderer/Preview/ModelPreview.vb b/Pilz.Drawing.Drawing3D.OpenGLRenderer/Preview/ModelPreview.vb
index 0172db4..f313bde 100644
--- a/Pilz.Drawing.Drawing3D.OpenGLRenderer/Preview/ModelPreview.vb
+++ b/Pilz.Drawing.Drawing3D.OpenGLRenderer/Preview/ModelPreview.vb
@@ -29,6 +29,7 @@ Namespace PreviewN
         Private ReadOnly myModels As New Dictionary(Of Object3D, Renderer)
         Private WithEvents RenderTimer As New Timers.Timer(25) With {.AutoReset = True}
         Private _EnableCameraControlling As Boolean = False
+        Private finishedLoading As Boolean = False
 
         Public Property Scaling As Single = 500.0F
         Public Property ClearColor As Color = Color.CornflowerBlue
@@ -125,13 +126,12 @@ Namespace PreviewN
         End Sub
 
         Public Sub New(objs As Object3D(), scale As Single)
-            Me.SuspendLayout()
+            SuspendLayout()
 
             InitializeComponent()
 
             'glControl1
             Dim glControl1 As New GLWpfControl
-            glControl1.IsEnabled = False
             Dim glControlHost = New ElementHost
             glControlHost.BackColor = Color.Black
             glControlHost.Name = "glControl1"
@@ -141,7 +141,6 @@ Namespace PreviewN
             glControlHost.MinimumSize = New Size(600, 120)
             glControlHost.TabIndex = 0
             glControlHost.TabStop = False
-            ResumeLayout(False)
 
             Me.glControl1 = glControl1
             Me.glControlHost = glControlHost
@@ -160,14 +159,16 @@ Namespace PreviewN
 
             ProjMatrix = Matrix4.CreatePerspectiveFieldOfView(FOV, glControlHost.Width / glControlHost.Height, 100.0F, 100000.0F)
 
+            ResumeLayout()
+
             MyCamera.SetCameraMode(CameraMode.FLY, camMtx)
             MyCamera.UpdateMatrix(camMtx)
 
-            Me.ResumeLayout()
-
             For Each obj As Object3D In objs
                 AddModel(obj)
             Next
+
+            finishedLoading = True
         End Sub
 
         Public Sub UpdateOrbitCamera()
@@ -177,12 +178,12 @@ Namespace PreviewN
         End Sub
 
         Public Sub UpdateView()
-            If glControl1.IsEnabled Then
+            If glControlHost.Enabled AndAlso finishedLoading Then
                 Invoke(Sub() InvalidateGL())
             End If
         End Sub
 
-        Public Sub InvalidateGL()
+        Private Sub InvalidateGL()
             glControl1.InvalidateVisual()
             glControlHost.Invalidate()
         End Sub
@@ -198,7 +199,6 @@ Namespace PreviewN
         End Sub
 
         Public Sub HandlesOnShown(sender As Object, e As EventArgs) Handles MyBase.Shown
-            glControl1.IsEnabled = True
             RenderModels()
             InvalidateGL()
         End Sub
@@ -248,9 +248,8 @@ Namespace PreviewN
 
         Public Sub HandlesOnPaint(renderTime As TimeSpan) Handles glControl1.Render
             GL.ClearColor(ClearColor)
-
             GL.Clear(ClearBufferMask.ColorBufferBit Or ClearBufferMask.DepthBufferBit)
-
+            GL.LoadIdentity()
             GL.MatrixMode(MatrixMode.Projection)
             GL.LoadMatrix(ProjMatrix)
             GL.MatrixMode(MatrixMode.Modelview)
@@ -262,6 +261,9 @@ Namespace PreviewN
                 End If
             Next
 
+            GL.End()
+            GL.Finish()
+
             'glControl1.SwapBuffers()
         End Sub