Terrains and Heightmaps Tutorial

This tutorial demonstrates how to render a heightmap-based terrain using the Terrain scene manager.

[From App_Terrain.hpp]

class App_Terrain: public BaseDemo
{
public:
  virtual void shutdown() {}

  virtual void run() {}

  virtual void initEvent()
  {
    if (!GLEW_ARB_multitexture)
    {
      vl::Log::error("GL_ARB_multitexture required.\n");
      openglContext()->quitApplication();
      return;
    }
    BaseDemo::initEvent();

    ghostCamera()->setMovementSpeed(5);
    // allocate terrain scene manager
    vl::ref<vl::Terrain> terrain = new vl::Terrain;
    // use GLSL?
    terrain->setUseGLSL(GLEW_ARB_shading_language_100?true:false);
    // dimensions of the terrain
    terrain->setWidth(100);
    terrain->setDepth(100);
    terrain->setHeight(5.0f);
    // heightmap texture size used by the GLSL program
    if (GLEW_ATI_texture_float || GLEW_ARB_texture_float)
      terrain->setHeightmapTextureFormat(vl::TF_LUMINANCE16F);
    else
      terrain->setHeightmapTextureFormat(vl::TF_LUMINANCE);
    // origin of the terrain
    terrain->setOrigin(vl::vec3(0,0,0));
    // define textures
    terrain->setHeightmapTexture("/images/terrain-h.jpg");
    terrain->setTerrainTexture("/images/terrain-t.jpg");
    terrain->setDetailTexture("/images/noise.png");
    terrain->setDetailRepetitionCount(8);
    // define shaders to be used to render the terrain
    terrain->setFragmentShader("/glsl/terrain.fs");
    terrain->setVertexShader("/glsl/terrain.vs");
    // initialize the terrain
    terrain->init();
    // add the terrain scene manager to the rendering
    vl::VisualizationLibrary::rendering()->as<vl::Rendering>()->sceneManagers()->push_back( terrain.get() );

    // adds fog if we are not using GLSL but the fixed function pipeline
    if (!terrain->useGLSL())
    {
      // set sky to white
      vl::VisualizationLibrary::rendering()->as<vl::Rendering>()->camera()->viewport()->setClearColor(vlut::white);
      // set fog render state
      vl::ref<vl::Fog> fog = new vl::Fog;
      fog->setColor(vlut::white);
      fog->setDensity(0.045f);
      fog->setMode(vl::FM_EXP);
      // install and enable fog
      terrain->shaderNode()->setRenderState(fog.get());
      terrain->shaderNode()->setEnable(vl::EN_FOG,true);
      terrain->shaderNode()->updateHierachy();
    }

    // for debugging purposes
    #if 0
      showBoundingVolumes(1,0);
    #endif
  }
};

// Have fun!