Loading terrain

Gorilla3D provides a simple terrain component for generation from height-map image. Besides the default usage, different procedural builders are available: diamond square, mandelbrot, perlin-noise (linear, cosine and cubic), plateau algorithms. The resolution / number of vertices is configurable.

For detailed information about the component and its methods, check out: Gorilla.Terrain

Form1.pas

uses
  Gorilla.Terrain,
  Gorilla.Material.Lambert;
 
procedure TForm1.FormCreate(Sender: TObject);
var LTexturePath : String;
begin
  LTexturePath := IncludeTrailingPathDelimiter(ExtractFilePath(ParamStr(0)));
 
  FTerrain := TGorillaTerrain.Create(fGorilla);
  FTerrain.Parent := FGorillaViewport;
 
  // set resolution of terrain to 256 x 256 sections
  // this generates 65.536 cells with 131.072 triangles and 393.216 vertices.
  FTerrain.ResolutionX := 256;
  FTerrain.ResolutionY := 256;
 
  // here we load the height map image
  FTerrain.HeightMap.LoadFromFile(LTexturePath + 'terrain-h.jpg');
 
  // adjust terrain size and scaling
  FTerrain.HeightScale := 10;
  FTerrain.Scale.X := 100;
  FTerrain.Scale.Y := 10;
  FTerrain.Scale.Z := 100;
 
  // build terrain mesh from previously loaded heightmap
  // 1st param: static buffering for large number of vertices.
  // 2nd param: decimation disabled
  FTerrain.RebuildTerrain(true, false);
 
  // apply a material as texture to it
  FTerrainMaterial := TGorillaLambertMaterial.Create(FTerrain);
  FTerrainMaterial.Parent := FTerrain;
  FTerrainMaterial.Texture.LoadFromFile(LTexturePath + 'terrain-c.jpg');
  FTerrain.Mesh.MaterialSource := FTerrainMaterial;
end;

Form1.pas

uses
  Gorilla.Terrain,
  Gorilla.Material.Lambert;
 
procedure TForm1.FormCreate(Sender: TObject);
var LTexturePath : String;
begin
  LTexturePath := IncludeTrailingPathDelimiter(ExtractFilePath(ParamStr(0)));
 
  FTerrain := TGorillaTerrain.Create(fGorilla);
  FTerrain.Parent := FGorillaViewport;
 
  // set resolution of terrain to 256 x 256 sections
  // this generates 65.536 cells with 131.072 triangles and 393.216 vertices.
  FTerrain.ResolutionX := 256;
  FTerrain.ResolutionY := 256;
 
  // adjust terrain size and scaling
  FTerrain.HeightScale := 10;
  FTerrain.Scale.X := 100;
  FTerrain.Scale.Y := 10;
  FTerrain.Scale.Z := 100;
 
  // build a random terrain by a predefined procedural algorithm
  FTerrain.RandomTerrain(TRandomTerrainAlgorithmType.DiamondSquare);
 
  // apply a material as texture to it
  FTerrainMaterial := TGorillaLambertMaterial.Create(FTerrain);
  FTerrainMaterial.Parent := FTerrain;
  FTerrainMaterial.Texture.LoadFromFile(LTexturePath + 'terrain-c.jpg');
  FTerrain.Mesh.MaterialSource := FTerrainMaterial;
end;

NOTICE: Once you build a random terrain, you are able to store the heightmap bitmap and reload later.

Implemented terrain algorithms:

This is a fixed result, but you could use this as basis for further computation. |

The component computes peaks by a specific number of random particles. Afterwards the complete terrain will be smooth to create a realistic landscape. |

You can also develop your own procedural algorithm by extending TRandomTerrainAlgorithm or any descendant. In the example below, we generate a random terrain:

MyTerrainAlg.pas

type
  TMyTerrainAlgorithm = class(TRandomTerrainAlgorithm)
    protected
      procedure Generate();
    public
      function GetHeightMap() : TBitmap; override;    
  end;  
 
{ TMyTerrainAlgorithm }
 
 
procedure TMyTerrainAlgorithm.Generate();
var x, z: Integer;
       i : Integer;
begin
  System.SetLength(FData, 256);
  for i := 0 to High(FData) do
    System.SetLength(FData[i], 256);
 
  for x := 0 to 255 do
    for z := 0 to 255 do
    begin
      FData[x, z] := Random(100) / 100;
    end;
end;
 
function TMyTerrainAlgorithm.GetHeightMap() : TBitmap;
begin
  Generate();
 
  result := inherited;
end;
 
LMyTerrainAlgorithm := TMyTerrainAlgorithm.Create();
try
  FTerrain.RandomTerrain(LMyTerrainAlgorithm);
finally
  FreeAndNil(LMyTerrainAlgorithm);
end;

It is recommend to use 2 ^ X resolution sizes for your terrain. Set resolution by the published properties “ResolutionX” and “ResolutionY”.

The table below lists common terrain sizes and their resulting vertices.

In case you are using a height-map smaller than your terrain-resolution, the resulting terrain could show some unlovely steps. Therefore the component provides the published “Smoothing” property. Set a value between 1 and 20 to apply smoothing algorithm onto your heightmap. A value of zero means that smoothing is deactivated.

Due to optimization reasons the component provides an experimental decimation algorithm.

// 1st parameter - static buffering of vertex data
// 2nd parameter - decimation algorithm execution
FTerrain.RebuildTerrain(true, >>>true<<<);

Generating a procedural terrain by algorithm, activate decimation like this:

// 1st parameter - type of terrain algorithm
// 2nd parameter - static buffering of vertex data
// 3rd parameter - decimation algorithm execution
FTerrain.RandomTerrain(TRandomTerrainAlgorithmType.DiamondSquare, true, >>>true<<<);

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