upgrade to .net6 part 2

Pilz.Drawing.Drawing3D.OpenGLRenderer/Preview/ModelPreview.vb

@@ -11,6 +11,7 @@ Imports OpenTK.Mathematics
 Imports OpenTK.WinForms
 Imports OpenTK.Input
 Imports OpenTK.Windowing.GraphicsLibraryFramework
+Imports Key = OpenTK3.Input.Key
 
 Namespace PreviewN
 
@@ -31,6 +32,12 @@ Namespace PreviewN
         Public Property Scaling As Single = 500.0F
         Public Property ClearColor As Color = Color.CornflowerBlue
 
+        Public ReadOnly Property Keyboard As OpenTK3.Input.KeyboardState
+            Get
+                Return OpenTK3.Input.Keyboard.GetState
+            End Get
+        End Property
+
         Public Property EnableCameraControlling As Boolean
             Get
                 Return _EnableCameraControlling
@@ -82,14 +89,14 @@ Namespace PreviewN
 
         Private ReadOnly Property IsStrgPressed As Boolean
             Get
-                Dim state As KeyboardState = Keyboard.GetState()
+                Dim state = Keyboard
                 Return state(Key.ControlLeft) OrElse state(Key.ControlRight)
             End Get
         End Property
 
         Private ReadOnly Property IsShiftPressed As Boolean
             Get
-                Dim state As KeyboardState = Keyboard.GetState()
+                Dim state = Keyboard
                 Return state(Key.ShiftLeft) OrElse state(Key.ShiftRight)
             End Get
         End Property
@@ -286,7 +293,7 @@ Namespace PreviewN
             Dim allowCamMove As Boolean = Not (IsMouseDown AndAlso IsShiftPressed)
 
             If allowCamMove Then
-                Dim state As KeyboardState = Keyboard.GetState
+                Dim state = Keyboard
 
                 If state(Key.W) Then
                     'camera.Move(moveSpeed, moveSpeed, camMtx)

Pilz.Drawing.Drawing3D.OpenGLRenderer/Rendering/Renderer.vb

@@ -1,9 +1,13 @@
 Imports System.Drawing
 Imports System.Threading
 Imports System.Windows.Forms
+
 Imports OpenTK
 Imports OpenTK.Graphics.OpenGL
+Imports OpenTK.Mathematics
+
 Imports Pilz.S3DFileParser
+
 Imports Bitmap = System.Drawing.Bitmap
 Imports Color = System.Drawing.Color
 Imports Image = System.Drawing.Image