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--- terrain [2019/05/02 15:14] – [Creating a terrain at runtime by procedural method] admin
+++ terrain [Unknown date] (current) – removed - external edit (Unknown date) 127.0.0.1
@@ Line 1: / Line 1: @@
-====== 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
-===== Creating a terrain at runtime from heightmap =====
-<file pascal 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;
-</file>
-===== Creating a terrain at runtime by procedural method =====
-<file pascal 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;
-</file>
-__NOTICE:__ Once you build a random terrain, you are able to store the heightmap bitmap and reload later.
-==== Implemented terrain algorithms ====
-^ Algorithm ^ Notice ^
-| Hill | A basic procedural hill algorithm. The algorithm will produce smooth hills by radius settings and a given count. |
-| DiamondSquare | A very popular algorithm to build random terrain. The algorithm creates randomly lows and highs for a realisic terrain. |
-| Mandelbrot | Creates the typical mandelbrot pattern: https://en.wikipedia.org/wiki/Mandelbrot_set This is a fixed result, but you could use this as basis for further computation. |
-| PerlinNoise | Perlin noise terrains are a good choice for random terrain. The component provides different mathmatical interpolation methods (linear, cosine, cubic). |
-| Plateau | A plateau terrain is described by a specific number of high and flat areas,  while the rest is much lower. The algorithm extends the TDiamondSquareTerrain. |
-| Brownian | Brownian terrains or brownian surface is based on the diamond square based terrain algorithm: https://en.wikipedia.org/wiki/Brownian_surface The component computes peaks by a specific number of random particles. Afterwards the complete terrain will be smooth to create a realistic landscape. |
-===== Creating an individual procedural terrain algorithm =====
-You can also develop your own procedural algorithm by extending TRandomTerrainAlgorithm or any descendant. In the example below, we generate a random terrain:
-<file pascal 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;
-</file>
-===== Resolution =====
-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.
-^ Size ^ Vertex-Count ^ Index-Count ^ Triangles ^ Memory-Size ^
-| 16 x 16 | 289 | 1536 | 512 | 26.952 Bytes |
-| 32 x 32 | 1089 | 6144 | 2048 | 102.984 Bytes |
-| 64 x 64| 4225 | 24.576 | 8192 | 402.504 Bytes |
-| 128 x 128 | 16.641 | 98.304 | 32.768 | 1.591.368 Bytes |
-| 256 x 256 | 66.049 | 393.216 | 131.072 | 6.328.392 Bytes |
-| 512 x 512 | 263.169 | 1.572.864 | 524.288 | 25.239.624 Bytes |
-| 1024 x 1024 | 1.050.625 | 6.291.456 | 2.097.152 | 100.810.824 Bytes |
-| 2048 x 2048 | 4.198.401 | 25.165.824 | 8.388.608 | 402.948.168 Bytes |
-===== Smoothing =====
-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.
-===== Decimation =====
-Due to optimization reasons the component provides an **experimental** decimation algorithm.
-<file pascal>
-// 1st parameter - static buffering of vertex data
-// 2nd parameter - decimation algorithm execution
-FTerrain.RebuildTerrain(true, >>>true<<<);
-</file>
-Generating a procedural terrain by algorithm, activate decimation like this:
-<file pascal>
-// 1st parameter - type of terrain algorithm
-// 2nd parameter - static buffering of vertex data
-// 3rd parameter - decimation algorithm execution
-FTerrain.RandomTerrain(TRandomTerrainAlgorithmType.DiamondSquare, true, >>>true<<<);
-</file>
-Next step: [[skybox|Skybox]]