Custom scene viewer

This application allows us to view a number of pre constructed scenes.

When the application starts you will see a blank window. When you click the + or - keys you can change the scene. By pressing the Tab button you will advance to the next render engine.

The following scenes have more primitive objects such as cones or cilinders. Again, you can see the scene with different render engines pressing Tab. Some of the scenes available include:

• Shapes
• Textures
• Normal mapping
• Reflective property
• Soft shadows

There are some scenes demonstrating reflective materials and mutiple point light shadows but they appear the same in ogre because they are not supported.

Compile and run the example

Clone the source code, create a build directory and use cmake and make to compile the code:

git clone https://github.com/gazebosim/gz-rendering
cd gz-rendering/examples/custom_scene_viewer
mkdir build
cd build
cmake ..
make

To run the example:

./custom_scene_viewer

Code

In the main function we can have a look at all the defined scenes.

  ManualSceneDemoPtr sceneDemo(new ManualSceneDemo);
  sceneDemo->AddScene(SceneBuilderPtr(new SceneBuilder));
  sceneDemo->AddScene(SceneBuilderPtr(new SimpleSceneBuilder));
  sceneDemo->AddScene(SceneBuilderPtr(new AllShapesSceneBuilder));
  sceneDemo->AddScene(SceneBuilderPtr(new TextureSceneBuilder));
  sceneDemo->AddScene(SceneBuilderPtr(new NormalMapSceneBuilder));
  sceneDemo->AddScene(SceneBuilderPtr(new ReflectionSceneBuilder));
  sceneDemo->AddScene(SceneBuilderPtr(new NormalReflectionSceneBuilder));
  // sceneDemo->AddScene(SceneBuilderPtr(new TransparencySceneBuilder));
  sceneDemo->AddScene(SceneBuilderPtr(new ShadowSceneBuilder(1)));
  sceneDemo->AddScene(SceneBuilderPtr(new ShadowSceneBuilder(2)));
  sceneDemo->AddScene(SceneBuilderPtr(new ShadowSceneBuilder(3)));
  sceneDemo->AddScene(SceneBuilderPtr(new ShadowSceneBuilder(4)));
  sceneDemo->AddScene(SceneBuilderPtr(new ShadowSceneBuilder(5)));

Inside SceneBuilder.cc some classes are defined which create the world. The method BuildScene will create the world for each scene.

For example, we can have a look at the SimpleSceneBuilder class inside SceneBuilder.cc. This class will only define the floor, the sphere and the light.

void SimpleSceneBuilder::BuildScene(ScenePtr _scene)
{
  SceneBuilder::BuildScene(_scene);
  VisualPtr root = _scene->RootVisual();
  _scene->SetAmbientLight(0.1, 0.1, 0.1);
 
  DirectionalLightPtr light = _scene->CreateDirectionalLight(LIGHT);
  light->SetDirection(0.3, 0.5, -1.0);
  light->SetDiffuseColor(0.8, 0.8, 0.8);
  light->SetSpecularColor(0.8, 0.8, 0.8);
  root->AddChild(light);
 
  VisualPtr sphere = _scene->CreateVisual(SPHERE);
  sphere->AddGeometry(_scene->CreateSphere());
  sphere->SetLocalPosition(3.0, 0.0, 0.5);
  sphere->SetLocalRotation(0.0, 0.0, 0.0);
  sphere->SetMaterial("Red");
  root->AddChild(sphere);
 
  VisualPtr plane = _scene->CreateVisual(PLANE);
  plane->AddGeometry(_scene->CreatePlane());
  plane->SetLocalPosition(3.0, 0.0, 0.0);
  plane->SetLocalRotation(0.0, 0.0, 0.0);
  plane->SetLocalScale(5.0, 10.5, 1.0);
  plane->SetMaterial("White");
  root->AddChild(plane);
}

The AllShapesSceneBuilder class inside SceneBuilder.cc will define more objects such us: CYLINDER, CONE or BOX.

void AllShapesSceneBuilder::BuildScene(ScenePtr _scene)
{
  SimpleSceneBuilder::BuildScene(_scene);
  VisualPtr root = _scene->RootVisual();
 
  VisualPtr cylinder = _scene->CreateVisual(CYLINDER);
  cylinder->AddGeometry(_scene->CreateCylinder());
  cylinder->SetLocalPosition(3.3, 1.0, 0.5);
  cylinder->SetLocalRotation(0.0, -0.5, 0.0);
  cylinder->SetLocalScale(0.5, 0.5, 1.5);
  cylinder->SetMaterial("Green");
  root->AddChild(cylinder);
 
  VisualPtr cone = _scene->CreateVisual(CONE);
  cone->AddGeometry(_scene->CreateCone());
  cone->SetLocalPosition(2.6, -0.8, 1.2);
  cone->SetLocalRotation(-0.5, -0.75, 0.0);
  cone->SetLocalScale(0.8, 0.8, 1.0);
  cone->SetMaterial("Blue");
  root->AddChild(cone);
 
  VisualPtr box = _scene->CreateVisual(BOX);
  box->AddGeometry(_scene->CreateBox());
  box->SetLocalPosition(2.2, -0.8, 0.2);
  box->SetLocalRotation(GZ_PI / 4, 0.0, GZ_PI / 4);
  box->SetLocalScale(0.5, 0.5, 0.5);
  box->SetMaterial("Yellow");
  root->AddChild(box);
}

The class TextureSceneBuilder includes all the objects and the textures:

void TextureSceneBuilder::BuildScene(ScenePtr _scene)
{
  AllShapesSceneBuilder::BuildScene(_scene);
 
  VisualPtr box = _scene->VisualByName(BOX);
  box->SetMaterial("TextureYellow");
 
  VisualPtr cone = _scene->VisualByName(CONE);
  cone->SetMaterial("TextureBlue");
 
  VisualPtr cylinder = _scene->VisualByName(CYLINDER);
  cylinder->SetMaterial("TextureGreen");
 
  VisualPtr plane = _scene->VisualByName(PLANE);
  plane->SetMaterial("TextureWhite");
 
  VisualPtr sphere = _scene->VisualByName(SPHERE);
  sphere->SetMaterial("TextureRed");
}

The class NormalMapSceneBuilder includes all the objects, the textures and the normal maps:

void NormalMapSceneBuilder::BuildScene(ScenePtr _scene)
{
  TextureSceneBuilder::BuildScene(_scene);
 
  VisualPtr box = _scene->VisualByName(BOX);
  box->SetMaterial("NormalYellow");
 
  VisualPtr cone = _scene->VisualByName(CONE);
  cone->SetMaterial("NormalBlue");
 
  VisualPtr cylinder = _scene->VisualByName(CYLINDER);
  cylinder->SetMaterial("NormalGreen");
 
  VisualPtr plane = _scene->VisualByName(PLANE);
  plane->SetMaterial("NormalWhite");
 
  VisualPtr sphere = _scene->VisualByName(SPHERE);
  sphere->SetMaterial("NormalRed");
}