History: Mogre Basic Tutorial VB 0

            Original version by [http://www.idleengineer.net|Clay Culver]

Initial C# edits by DigitalCyborg & ElectricBliss

Adapted to MOGRE by Adis

VB.NET port by ((User:Aeauseth|Aeauseth)).

{maketoc}

!!Getting Started
!!!Prerequisites
This tutorial assumes you have knowledge of VB.NET programming and are able to setup and compile a standard VB.NET application. You should have Visual Basic 2008 (the free [http://msdn.microsoft.com/vstudio/express/vb/|Express Version] will work fine) or [http://www.sharpdevelop.com|SharpDevelop] installed.

!!!Introduction
In this tutorial we will be going over how to install Mogre and how to setup and run a Mogre application. We will also go over some of the pitfalls of Mogre and how to avoid them, as well as proper Ogre exception handling. If you have questions about this tutorial, or Mogre in general, you should ask the question in the [http://www.ogre3d.org/phpBB2addons/viewforum.php?f=8|Mogre Forums].

!!Installation
!!!Downloading Mogre
You can download the latest version of Mogre from the [http://sourceforge.net/projects/mogre|Mogre SourceForge project page]. The filename is MogreSDK_1.4.8.exe, although there may be a newer version at some point. When you install the SDK, you will be given the choice of installation locations. This tutorial will assume you have installed the MogreSDK in default location (C:\MogreSDK).

You will also need [http://www.microsoft.com/downloads/details.aspx?familyid=32BC1BEE-A3F9-4C13-9C99-220B62A191EE&displaylang=en|vcredist_x86.exe]; check it out in the same URL above. Some users reported that applications executed correctly after installation (e.g.: Visual Studio 2005, Team Edition, Version 8.0.50727-42).

Alternatively you can install the [http://msdn2.microsoft.com/en-us/vstudio/bb265237.aspx|SP1 for your IDE] (Visual Studio, [http://www.microsoft.com/express/vcsharp|Visual|C# Express], etc.) So you also can use the debug version of DLL files.

To use the Direct3D9-Renderer you need to install the [http://www.microsoft.com/downloads/details.aspx?FamilyId=1A2393C0-1B2F-428E-BD79-02DF977D17B8&displaylang=en|DirectX Redistributables from November 2007] or newer.

!!Building Your First Mogre Application
!!!Creating a Project
Open up Visual Basic and create a new Console Application. Name it MogreTutorial0 (or whatever). 
Now that we have a project created, we need to add references to it.

!!!Adding References
From the menu bar click “Project”, then “Add Reference”. Click on the "Browse" tab, and change the directory to "C:\MogreSDK\bin\release". Select __Mogre.dll__ and then click "OK". Do this again for __Mois.dll__.

!!!Adding C++ dlls
The Mogre and Mois references are just 'wrappers' for the Ogre C++ dll's, hence the purpose of MOgre. These wrappers are dependant on several files, and we need to add these files to our project.

From the menu bar click “Project”, then “Add Existing Item”. Browse to "C:\MogreSDK\bin\release" and select __OgreMain.dll__ and then click "OK". Do this again for __cg.dll__ and __OIS.dll__.

Now you should see __OgreMain.dll__ in the Solution Explorer. Left click on __OgreMain.dll__ to select it. Take a look at the Properties window and you will see the “Copy to Output Directory” witch defaults to “Do not copy”. Change this to “Copy if newer”. Set __cg.dll__ and __OIS.dll__ to "Copy if newer".

!!!Adding Configuration Files
Before we can actually use the project, we have to add three configuration files to our project. From the menu bar click “Project”, then “Add Existing Item”. Browse to "C:\MogreSDK\bin\release" and select __media.cfg__, __Plugins.cfg__, and __resources.cfg__. Select each one from the Solution Explorer and set to “Copy if newer”. 
For simplicity we are going to use the resources located in C:\MogreSDK. However to make this a self contained and publishable program you would want to add these resources files to your project. But for now, open up the resources.cfg files you added to your project. You will notice it contains a relative path for the directories. We will have to set this manually to the absolute path. Replace all occurrences of "../../" in the document with "C:\MogreSDK\". Don’t worry about which direction the slashes are going, windows doesn’t really care.
We need to do the same thing to Plugins.cfg. Open the file and make sure the PluginFolder=C:\MogreSDK\bin\release

!!!Testing Your Application
Now that the project is fully setup and ready to be used, open up "Module1.vb" and replace the code with the following:

{CODE(wrap="1",colors="vbnet")}Imports Mogre
 
 Module Module1
    Sub Main()
 
      Try
 
             'Initialization of Ogre Root and RenderWindow
             Dim myRoot As Root = New Root("Plugins.cfg", "ogre.cfg", "ogre.log")
 
             'Show Ogre Rendering Subsystem setup dialog box
             If Not myRoot.RestoreConfig Then
                 If Not myRoot.ShowConfigDialog Then
                     Exit Sub
                 End If
             End If
 
             'Create an Ogre render window
             Dim myWindow As RenderWindow = myRoot.Initialise(True, "Application")
 
             'Start rendering
             myRoot.StartRendering()
 
      Catch ex As System.Runtime.InteropServices.SEHException
           If OgreException.IsThrown Then
                MsgBox(OgreException.LastException.FullDescription, MsgBoxStyle.Critical, _
                     "An Ogre  exception has occured!")
           Else
                MsgBox(ex.ToString, "An error has occured")
           End If
      End Try
 
    End Sub
 End Module{CODE}

From the main menu click “File” and then “Save All”. Run the application by pressing F5. You should see black dos type window, then a dialog box that allows you to pick a rendering subsystem. Pick “Direct3D9 Rendering Subsystem”. You should also set “Full Screen” to “No”. Click OK and you will see a second black window titled “Application” with a black background. If so, congratulations! You have just successfully created your first Ogre project. We will be doing more with this later.

!!Troubleshooting
!!!Checklist
If you have problems getting started, check the following things first:

* Did you install the Mogre SDK and NOT the standard OgreSDK? The Mogre SDK can be obtained from the [http://sourceforge.net/projects/mogre]. The Mogre SDK will include Mogre.dll in the C:\MogreSDK\bin\debug and C:\MogreSDK\bin\release directories.
* FileLoadException was unhandled and something about a prodecure imported by 'Mogre, Version=1.4.6.0'? First disable the [http://msdn2.microsoft.com/en-us/library/ms185330(VS.80).aspx|Visual Studio hosting process].
* Did you download more than one version of Ogre? If so then close Visual Basic. Delete the C:\MogreSDK directory, rerun the MOgreSDK extract. Remember the MOgre and Ogre have different SDK's! Delete all the files in your “MyDocuments\Visual Studio 2008\Projects\MogreTutorial0\MogreTutorial0\bin\Debug” and “MyDocuments\Visual Studio 2008\Projects\MogreTutorial0\MogreTutorial0\bin\Release” directories. Restart Visual Basic and load your project. Now delete all the DLL's in your Solution Explorer. Re-add them (see previous section if you forgot how to do this).
* Did you add references to "Mogre.dll" in your project?
* Browse to “MyDocuments\Visual Studio 2008\Projects\MogreTutorial0\MogreTutorial0\bin\Debug”. You should have cg.dll, mogre.dll, ogremain.dll, and Plugins.cfg files. If not review the previous sections to see what you missed.
* Browse to “MyDocuments\Visual Studio 2008\Projects\MogreTutorial0\MogreTutorial0\bin\Debug”. Is there an ogre.log file? If so open it and see if there are any errors reported.
* The application has failed to start because d3dx9_36dll was not found. Note that your Plugins.cfg file has the line Plugin=RenderSystem_Direct3D9. This is required in order to use the Direct3D9-Renderer. However it is also required that you have [http://www.microsoft.com/downloads/details.aspx?FamilyId=1A2393C0-1B2F-428E-BD79-02DF977D17B8&displaylang=en|DirectX Redistributables from November 2007] or newer installed (don't forget to run DXsetup after the download). Try commenting out the line Plugin=RenderSystem_Direct3D9 (use a #) and see if it works.

!!!Getting Help
If you have checked these things, feel free to post the problem you are having to the [http://www.ogre3d.org/phpBB2addons/viewforum.php?f=8|Mogre forums]. Be sure to include a detailed description of the problem, the things you have tried to fix it, and paste the error messages from the Ogre.log file if there are any (this file is located in the project's output directory).

!!Exception Handling With Mogre
Before wrapping up this tutorial, I'd like to breifly mention how to handle exceptions which originate from Ogre itself. Mogre and VB can handle C++ exceptions, but they do not act as you would expect them to. If you ever see a message which states "Runtime Error! ... This application has requested the Runtime to terminate in an unusual way..." then you probably encountered an error in Ogre somewhere.

To properly handle an exception thrown by the C++ Ogre library, you need to catch an exception of the type System.Runtime.InteropServices.SEHException. After catching this exception, you can see if it's an Ogre exception (instead of just a crash) by checking the static OgreException.IsThrown property. If that property is true, then you handle the exception. For example, here is a chunk of code to catch and display an Ogre exception:

{CODE(wrap="1",colors="vbnet")}Try
 …
 Catch ex As System.Runtime.InteropServices.SEHException
      If OgreException.IsThrown Then
           MsgBox(OgreException.LastException.FullDescription, MsgBoxStyle.Critical, _
                "An Ogre  exception has occured!")
      Else
           MsgBox(ex.ToString, "An error has occured")
      End If
 End Try{CODE}

Wrapping your main method with a try block such as this one can save you lots of headaches down the line when you are debugging your application. Notice we have not added a catch block to catch a generic Exception object. This way when we are debugging the application, Visual Basic can insert a breakpoint for an unhandled VB exception, whereas Visual Basic cannot do this for C++ exceptions.

!!Final Note
By this point you should be able to create and run an empty Mogre project. All subsequent tutorials will assume you can successfully set up a Mogre project. 
Also, a possible way to speed up the creation of new Mogre projects is to create a new Template. From the main menu select “File” then “Export Template”. Take the defaults, although I recommend changing the Template name to “Mogre”.

Proceed to ((Mogre Basic Tutorial VB 1)) ''The SceneNode, Entity, and SceneManager constructs''