Wie ruft man POVRAY aus einem Programm heraus auf ?

[mrpix777]

Tja, ist schon eine Weile her, daß diese Frage gestellt wurde!
Ich starte schon sehr lange das PovRay Rendering Programm (http://www.povray.org/) von meinem 3d-Programm aus.
Eine etwas umfangreichere Lösung zur gestellten Frage möchte ich allen Interessierten nicht vorenthalten, da man sonst zu diesem Thema eher wenig detaillierte Infos erhält.

Das Testprogramm geht wie folgt vor:
- übergebene Programmparameter checken
- Startkommando aus Registry checken
- ev. eigenes Startkommando verwenden
- PovRay starten und dabei Bild als PNG-Datei speichern

Übrigens, der Unterschied der beiden Exe-Dateien ist beachtlich!

Delphi-Quellcode:

//********************************************************************
// Project File:   PovRayStarter.dpr  v1.02   2021-01-03
// A Delphi console example program for starting 'PovRay rendering'.
// PovRayStarter.exe tested with:  Delphi-6 release with      8.704 Bytes
//                                 Delphi-Sydney-CE with  1.162.752 Bytes
// Ref.: https://www.delphipraxis.net/35458-wie-ruft-man-povray-aus-einem-programm-heraus-auf.html
//********************************************************************
{$D+,L+,Y+,R+,S+,Q+,O-,C+}   // debug
{$D-,L-,Y-,R-,S-,Q-,O-,C-}   // release

{$APPTYPE CONSOLE}

program PovRayStarter;

uses  SysUtils, ShellApi, Windows, Registry;

const
  NL = #13#10;   // NewLine = carriage return + linefeed
  PovRayStartCommand36 = 'C:/Program Files/POV_Ray/POV-Ray 3.6/bin/pvengine.exe +FP ';
  PovRayStartCommand37 = 'C:/Program Files/POV_Ray/POV-Ray 3.7/bin/pvengine.exe ';
  // set your individual start command here:
  PovRayStartCommand37b= 'E:\Programming_Tools\POV_Ray\POV-Ray_3.7\bin\pvengine32-sse2.exe';

var
  povStartCommand, povStartParams: string;

//*********************************************************
// Gets a string value from the registry from the given root and sub key.
// Converts integer value to a string
// Returns '', if the sub key or value name are unknown.
//---------------------------------------------------------
function GetRegistryString (const rootKey: HKEY;
                            const subKey, name: string): string;
var
  reg: TRegistry;            // registry access object
  valueInfo: TRegDataInfo;   // info about registry value
begin
  Result := '';
  reg := TRegistry.Create;
  try
    reg.RootKey := rootKey;
    if reg.OpenKeyReadOnly (subKey)
    then if reg.GetDataInfo (name, valueInfo)  // check if registry value is string or integer
    then begin
      case valueInfo.RegData of
        // string value: just return it
        rdString, rdExpandString:   Result := reg.ReadString (name);
        // integer value: convert to string
        rdInteger:   Result := IntToStr (reg.ReadInteger(name));
      end;
    end;
  finally
    reg.CloseKey;
    reg.Free;
  end;
end;
//*********************************************************
// get start command of PovRay Renderer
//---------------------------------------------------------
procedure GetPovRayStartCommand;
var si: integer;
begin
  povStartCommand := paramStr(1);
  if povStartCommand = ''
  then begin
    povStartCommand := GetRegistryString (HKEY_CLASSES_ROOT
                    , '\Applications\pvengine.exe\shell\open\Command', '');
    if povStartCommand <> ''
    then begin
      // cut text after 'pvengine.exe"'
      si := pos('pvengine.exe"', povStartCommand);
      if si > 0
      then delete (povStartCommand, si+13, 999);
    end;
  end;
  if povStartCommand = ''
  then povStartCommand := PovRayStartCommand36;
  if povStartCommand = '' then
    povStartCommand := PovRayStartCommand37;
  writeln ('Start command of PovRay program : '#13#10,'  ', povStartCommand);
end;
//*********************************************************
// execute Windows application
// input:    name: string     application name
//           param: string    application start parameters
// result:   boolean          =true application started
//           errorCode        e.g.  2 = ERROR_FILE_NOT_FOUND
// see:      https://docwiki.embarcadero.com/RADStudio/Sydney/en/Input-Output_Errors
// examples: started := RunApplication ('pvengine.exe', '/RENDER example.pov');
//           started := RunApplication ('ReadMe.txt', '');  // view text file
//           RunApplication ('notepad', 'info.txt');        // view text file with notePad
//           RunApplication ('Explorer', 'C:\');            // start windows explorer
//---------------------------------------------------------
function RunApplication (const name, param: string): boolean;
var   errorCode: cardinal;
begin
  writeln (NL,'try starting PovRay with command...', NL, name, param);

  errorCode := ShellExecute (0, 'open', PChar(name), PChar(param), nil, SW_SHOWNORMAL);

  result := (errorCode = 0) or (errorCode = 42);
  if result
  then writeln ('  successfully started ')
  else writeln ('RunApplication:  ', NL
               ,'  can not start application ''', name+param, '''' + NL
               ,'  error code = ' + IntToStr(errorCode));

  // german info from Delphi-Praxis:
  //   https://www.delphipraxis.net/126563-shellexecute-error.html
end;
//*********************************************************
// start rendering of povray scene
//---------------------------------------------------------
procedure StartPovRayRendering (const povfilename: string);
var
  result: boolean;
begin
  povStartParams := ' /EDIT ' + povfilename
                  + ' /RENDER ' + povfilename
                  + ' +FN';   // PNG output see http://www.povray.org/documentation/view/3.6.1/219/

  // try to start PovRay 3.6
  result := RunApplication (povStartCommand, povStartParams);
  if not result
  // try to start PovRay 3.7b
  then RunApplication (PovRayStartCommand37b, povStartParams);
end;
//*********************************************************
// create povray test scene file
//---------------------------------------------------------
procedure SavePovRayTestFile (const povfilename: string);
var  pov: text;
begin
  Assign (pov, povfilename);
  ReWrite (pov);
  writeln (pov, '// File: ' + povfilename, NL
              , 'camera {location -3*z}', NL
              , 'light_source {<9,9,-9> 1 parallel}', NL
              , 'sphere {0 1 pigment {rgb<1,1,0.5>}}', NL);
  Close (pov);
end;
//*********************************************************
const
  povFilename = 'Test1.pov';
begin
  writeln (NL, '=== PovRayStarter v1.02 ===', NL);
  SavePovRayTestFile (povFilename);
  GetPovRayStartCommand;
  StartPovRayRendering (povFilename);
  sleep(7000);
end.