Houdini Engine for Unreal (Improved Path Handling on Windows)

HoudiniEngineRuntime.Build.cs

// [GIST NOTE] Added at the bottom of the existing class (for editor and runtime).

// Check the system environment variables for HOUDINI_PATH (instead of just hard-coded path searching like the default plugin does).
public static bool GetHoudiniPath( int PluginVersionMajor, int PluginVersionMinor, int PluginVersionPatch, out string HoudiniPathOut )
{
  string version = null;

  // Do the easy check: an environment variable I recommend to people (trent, 12/31/17).
  HoudiniPathOut = System.Environment.GetEnvironmentVariable("HOUDINI_PATH", System.EnvironmentVariableTarget.User);
  if ( !string.IsNullOrEmpty( HoudiniPathOut ) )
  {
    // NOTE (trent, 12/31/17): Can't do a version check in this case (I have it installed to a \Houdini\ path instead of \Houdini <version>\). Maybe could do a regex for "{number}.{number}.{number}" somewhere if needed?

		// Ensure that any backslashes are replaced with forward slashes (or the C++ code gets angry).
		HoudiniPathOut = HoudiniPathOut.Replace( "\\", "/" );
    
    System.Console.WriteLine( string.Format( "[Houdini Engine Plugin (Editor)]: Found Houdini path successfully ({0}).", HoudiniPathOut ) );
    return true;
  }

  // Interrogate the Win32 registry.
  Microsoft.Win32.RegistryKey sideEffectsKey = Microsoft.Win32.RegistryKey.OpenBaseKey( Microsoft.Win32.RegistryHive.LocalMachine, Microsoft.Win32.RegistryView.Default ).OpenSubKey( "SOFTWARE\\Side Effects Software" );
  if( sideEffectsKey == null )
  {
    // Likely does not have Houdini uninstalled.
    HoudiniPathOut = null;

    System.Console.WriteLine( "[Houdini Engine Plugin (Editor)] WARNING: HOUDINI_PATH (and registry) failed to locate Houdini." );
    return false;
  }

  version = sideEffectsKey.GetValue( "ActiveVersion" ) as string;
  if( string.IsNullOrEmpty( version ) )
  {
    // Likely does not have Houdini uninstalled.
    System.Console.WriteLine( "[Houdini Engine Plugin (Editor)] WARNING: HOUDINI_PATH (and registry) failed to locate Houdini." );
    return false;
  }

  // Query the path specified in the Houdini regkey.
  string key = string.Format( "SOFTWARE\\Side Effects Software\\Houdini {0}", version );
  Microsoft.Win32.RegistryKey houdiniKey =  Microsoft.Win32.RegistryKey.OpenBaseKey( Microsoft.Win32.RegistryHive.LocalMachine, Microsoft.Win32.RegistryView.Default ).OpenSubKey( key );
  if( houdiniKey == null )
  {
    // Likely does not have Houdini uninstalled.
    System.Console.WriteLine( "[Houdini Engine Plugin (Editor)] WARNING: HOUDINI_PATH (and registry) failed to locate Houdini." );
    return false;
  }

  HoudiniPathOut = houdiniKey.GetValue( "InstallPath", "" ) as string;
  if( string.IsNullOrEmpty( HoudiniPathOut ) )
  {
    // Failed to find the path.
    System.Console.WriteLine( "[Houdini Engine Plugin (Editor)] WARNING: HOUDINI_PATH (and registry) failed to locate Houdini." );
    return false;
  }

  // Do a little bit more to check the version.
  string pluginVersion = PluginVersionMajor + "." + PluginVersionMinor + "." + PluginVersionPatch;

  // Do a trivial check for the same version.
  if( version == pluginVersion )
  {
    // Neat.
    return true;
  }

  // Parse the version key for comparison with the plugin version.
  //	NOTE (trent, 12/31/17): I'm only spitting out a warning if the installed version predates the plugin version; if only a direct match is desired, this can all be removed and replaced with a string comparison.

  {
    string[] versionValues = System.Text.RegularExpressions.Regex.Split( version, @"\D+" );
    int iteration = 0;

    foreach ( string value in versionValues )
    {
      if( !string.IsNullOrEmpty( value ) )
      {
        int i = int.Parse( value );
        if( i < ( ( iteration == 0 ) ? PluginVersionMajor : ( iteration == 1 ? PluginVersionMinor : PluginVersionPatch ) ) )
        {
          string versionWarning = string.Format( "[Houdini Engine Plugin (Editor)] WARNING: Houdini version found ({0}) precedes plugin version ({1}).", version, pluginVersion );
          System.Console.WriteLine( versionWarning );

          break;
        }
      }

      ++iteration;
    }
  }
  
  // Ensure that any backslashes are replaced with forward slashes (or the C++ code gets angry).
  HoudiniPathOut = HoudiniPathOut.Replace( "\\", "/" );

  string foundRegistryPath = string.Format( "[Houdini Engine Plugin (Editor)]: Found Houdini path successfully ({0}).", HoudiniPathOut );
  System.Console.WriteLine( foundRegistryPath );
  return true;
}


// [GIST NOTE]: Replace class definition line.
  // Runtime:
[SupportedPlatforms(UnrealTargetPlatform.Win64)]
public class HoudiniEngineRuntime : ModuleRules

  // Editor:
[SupportedPlatforms(UnrealTargetPlatform.Win64)]
public class HoudiniEngineEditor : ModuleRules


// [GIST NOTE]: Replaces the existing version string (just builds it from the int values).
int versionMajor = 16, versionMinor = 5, versionPatch = 332;
string HoudiniVersion = versionMajor + "." + versionMinor + "." + versionPatch;


// [GIST NOTE]: Replaces existing Windows path logic.
if( platformId == PlatformID.Win32NT )
{
  if( !GetHoudiniPath( versionMajor, versionMinor, versionPatch, out HFSPath ) )
  {
    // We first check if Houdini Engine is installed.
    //	NOTE (trent, 12/31/17): The more useful way using a user-set environment variables (HOUDINI_PATH) or, if that fails, checking the registry. If that still fails, then use the hard-coded versioned path.
    string HPath = "C:/Program Files/Side Effects Software/Houdini Engine " + HoudiniVersion;
    if( !Directory.Exists( HPath ) )
    {
      // If Houdini Engine is not installed, we check for Houdini installation.
      HPath = "C:/Program Files/Side Effects Software/Houdini " + HoudiniVersion;
      if( !Directory.Exists( HPath ) )
      {
        if ( !Directory.Exists( HFSPath ) )
        {
          string Err = string.Format( "Houdini Engine : Please install Houdini or Houdini Engine {0}", HoudiniVersion );
          System.Console.WriteLine( Err );
        }
      }
      else
      {
        HFSPath = HPath;
      }
    }
    else
    {
      HFSPath = HPath;
    }
  }
}