Tips and Tricks

Accessing the Parameter Block of Any Plug-in - If a plug-in does not explicitly provide access to its parameter blocks, you can still access it by iterating over the references. The following returns a pointer to the first parameter block of any plug-in:

IParamBlock2* GetParamBlock(ReferenceMaker* obj) {
    int nRefs = obj->NumRefs();
    for ( int i = 0; i < nRefs; ++i ) {
        ReferenceTarget* ref = obj->GetReference(j);
    if ( ref && ref->SuperClassID() == PARAMETER_BLOCK2_CLASS_ID ) {
        returndynamic_cast<IParamBlock2*>( ref );
    }
    }
    return NULL;
}

Executing Code in Main Thread - You can execute code safely in the main thread of 3ds Max by either creating a Windows timer object using the main 3ds Max window as the window handle, or by using the following function to trigger code when 3ds Max is next idle.

#define WM_TRIGGER_CALLBACK WM_USER+4764
void PostCallback( void (*funcPtr)(UINT_PTR), UINT_PTR param )
{
    PostMessage( GetAppHWnd(), WM_TRIGGER_CALLBACK, (UINT_PTR)funcPtr, (UINT_PTR)param );
}

In .NET, the System.Windows.Dispatcher class can be used to achieve the same effect. See MSDN () for more information about this class.

Executing a Python Script from a .NET Assembly - After downloading and installing IronPython, you can execute a Python script from a .NET assembly with a few lines of code as follows:

using IronPython.Hosting;
using Microsoft.Scripting.Hosting;
public static void RunPythonFile(string filename) {
    try  {
        var options = new Dictionary<string, object>();
        options["Debug"] = true;
        ScriptEngine se = Python.CreateEngine(options);
        ScriptSource ss = se.CreateScriptSourceFromFile(filename);
        CompiledCode cc = ss.Compile();
        cc.Execute();
    }
    catch (Exception e){
    MessageBox.Show("Error occurred: " + e.Message);
    }
}

Execute Code in C# - You can execute code in C# after 3ds Max is fully initialized by registering a callback with the notification listener as shown in the following example:

using ManagedServices;
public class My3dsMaxAssembly
{
    public const int StartUpNotification = 0x50;
    public static void AssemblyMain()
    {
    // This causes an event to be raised once the 3ds Max application has been started 
    var m = new MaxNotificationListener(StartUpNotification);
    m.NotificationRaised += new EventHandler<MaxNotificationEventArgs>(AfterStartup); 
    } 
    public static void AfterStartup(object sender, MaxNotificationEventArgs e) { 
    if (e.NotificationCode == StartUpNotification) { 
        // Do whatever 
    } 
    } 
} 

Generate C++ Code from Mesh Data - If you create a mesh using 3ds Max and wish to capture the data as a sequence of C++ instructions for manually constructing the mesh can be very time consuming if the object contains a large number of vertices.

The MAXScript script found in the SDK under howto\objects\widget\mesh2cpp.ms can be used to write all the mesh generating instructing information to a header (.h) file that you can include in your project. The script can be found Here is how to use the script:

1. Open the script and evaluate it. This will compile the script and create an action entry in the 3dsmax action system.
2. In the Customize > Customize User Interface ... dialog, look up the command Mesh2CPP under the 'SDK Tools" category.
3. Assign this command to a button or hotkey.
4. Select your object in the viewport.
5. Run the script. A Save As dialog will appear.
6. Specify the header filename and select Save.

This will generate a header (.h) file that you can copy or include into the source of your plug-in.