Custom shadow caster materials (#3048)

This allows the shadow caster material name to be specified
in a `<ignition:shadow_caster_material_name/>` SDFormat
element under `<scene/>`. To avoid breaking ABI, this
data is not added to the `scene.proto` message, but
instead is exposed through an ign-transport service named
`/shadow_caster_material_name` by `physics::World`.

An example material is provided that avoids heightmap
self-shadowing and is used in a test.

Signed-off-by: William Lew <WilliamMilesLew@gmail.com>

* Improve console messages
* Remove input parameter from service

Signed-off-by: Steven Peters <scpeters@openrobotics.org>
Co-authored-by: Steven Peters <scpeters@openrobotics.org>

gazebo/physics/World.cc

@@ -217,6 +217,18 @@ void World::Load(sdf::ElementPtr _sdf)
       msgs::SceneFromSDF(this->dataPtr->sdf->GetElement("scene")));
   this->dataPtr->sceneMsg.set_name(this->Name());
 
+  if (this->dataPtr->sdf->GetElement("scene")->
+      HasElement("ignition:shadow_caster_material_name"))
+  {
+    this->dataPtr->shadowCasterMaterialName =
+      this->dataPtr->sdf->GetElement("scene")->
+        Get<std::string>("ignition:shadow_caster_material_name");
+  }
+  else
+  {
+    this->dataPtr->shadowCasterMaterialName = "Gazebo/shadow_caster";
+  }
+
   // The period at which messages are processed
   this->dataPtr->processMsgsPeriod = common::Time(0, 200000000);
 
@@ -284,6 +296,14 @@ void World::Load(sdf::ElementPtr _sdf)
         << std::endl;
   }
 
+  std::string shadowCasterService("/shadow_caster_material_name");
+  if (!this->dataPtr->ignNode.Advertise(shadowCasterService,
+      &World::ShadowCasterService, this))
+  {
+    gzerr << "Error advertising service [" << shadowCasterService << "]"
+        << std::endl;
+  }
+
   // This should come before loading of entities
   sdf::ElementPtr physicsElem = this->dataPtr->sdf->GetElement("physics");
 
@@ -3337,3 +3357,10 @@ bool World::PluginInfoService(const ignition::msgs::StringMsg &_req,
 
   return false;
 }
+
+//////////////////////////////////////////////////
+bool World::ShadowCasterService(ignition::msgs::StringMsg &_res)
+{
+  _res.set_data(this->dataPtr->shadowCasterMaterialName.c_str());
+  return true;
+}

gazebo/physics/World.hh

@@ -651,6 +651,11 @@ namespace gazebo
       private: bool PluginInfoService(const ignition::msgs::StringMsg &_request,
           ignition::msgs::Plugin_V &_plugins);
 
+      /// \brief Callback for "<this_name>/shadow_caster_material_name" service.
+      /// \param[out] _response Message containing shadow caster material name
+      /// \return True if the info was successfully obtained.
+      private: bool ShadowCasterService(ignition::msgs::StringMsg &_response);
+
       /// \internal
       /// \brief Private data pointer.
       private: std::unique_ptr<WorldPrivate> dataPtr;

gazebo/physics/WorldPrivate.hh

@@ -385,6 +385,9 @@ namespace gazebo
 
       /// \brief SDF World DOM object
       public: std::unique_ptr<sdf::World> worldSDFDom;
+
+      /// \brief Shadow caster material name from scene SDF
+      public: std::string shadowCasterMaterialName;
     };
   }
 }

gazebo/rendering/RTShaderSystem.cc

@@ -796,8 +796,9 @@ void RTShaderSystem::UpdateShadows(ScenePtr _scene)
   // sceneMgr->setShadowTextureCasterMaterial("PSSM/shadow_caster");
 #if OGRE_VERSION_MAJOR == 1 && OGRE_VERSION_MINOR >= 11
   sceneMgr->setShadowTextureCasterMaterial(
-      Ogre::MaterialManager::getSingleton().getByName("Gazebo/shadow_caster"));
+      Ogre::MaterialManager::getSingleton().getByName(
+      _scene->ShadowCasterMaterialName()));
 #else
-  sceneMgr->setShadowTextureCasterMaterial("Gazebo/shadow_caster");
+  sceneMgr->setShadowTextureCasterMaterial(_scene->ShadowCasterMaterialName());
 #endif
 }

gazebo/rendering/Scene.cc

@@ -206,6 +206,26 @@ Scene::Scene(const std::string &_name, const bool _enableVisualizations,
 
   this->dataPtr->sceneSimTimePosesApplied = common::Time();
   this->dataPtr->sceneSimTimePosesReceived = common::Time();
+
+  // Get shadow caster material name from physics::World
+  ignition::transport::Node node;
+  ignition::msgs::StringMsg rep;
+  const std::string serviceName = "/shadow_caster_material_name";
+  bool result;
+  unsigned int timeout = 5000;
+  bool executed = node.Request(serviceName,
+      timeout, rep, result);
+  if (executed)
+  {
+    if (result)
+      this->dataPtr->shadowCasterMaterialName = rep.data();
+    else
+      gzerr << "Service call[" << serviceName << "] failed" << std::endl;
+  }
+  else
+  {
+    gzerr << "Service call[" << serviceName << "] timed out" << std::endl;
+  }
 }
 
 //////////////////////////////////////////////////
@@ -3285,6 +3305,12 @@ unsigned int Scene::ShadowTextureSize() const
     return this->dataPtr->shadowTextureSize;
 }
 
+/////////////////////////////////////////////////
+std::string Scene::ShadowCasterMaterialName() const
+{
+  return this->dataPtr->shadowCasterMaterialName;
+}
+
 /////////////////////////////////////////////////
 void Scene::AddVisual(VisualPtr _vis)
 {

gazebo/rendering/Scene.hh

@@ -127,6 +127,7 @@ namespace gazebo
       /// \brief Process all received messages.
       public: void PreRender();
 
+
       /// \brief Wait until a render request occurs
       /// \param[in] _timeoutsec timeout expressed in seconds
       /// \return True if timeout was NOT met
@@ -380,6 +381,7 @@ namespace gazebo
                             const ignition::math::Vector3d &_end,
                             const std::string &_name);
 
+
       /// \brief Set the fog parameters.
       /// \param[in] _type Type of fog: "linear", "exp", or "exp2".
       /// \param[in] _color Color of the fog.
@@ -418,6 +420,10 @@ namespace gazebo
       /// \return Size of the shadow texture. The default size is 1024.
       public: unsigned int ShadowTextureSize() const;
 
+      /// \brief Get the shadow caster material name
+      /// \return Name of the shadow caster material
+      public: std::string ShadowCasterMaterialName() const;
+
       /// \brief Add a visual to the scene
       /// \param[in] _vis Visual to add.
       public: void AddVisual(VisualPtr _vis);

gazebo/rendering/ScenePrivate.hh

@@ -376,6 +376,9 @@ namespace gazebo
       /// \brief State of each layer where key is the layer id, and value is
       /// the layer's visibility.
       public: std::map<int32_t, bool> layerState;
+
+      /// \brief Shadow caster material name
+      public: std::string shadowCasterMaterialName;
     };
   }
 }

media/materials/programs/CMakeLists.txt

@@ -43,6 +43,7 @@ point_receiver_vp.glsl
 projector.frag
 projector.vert
 shadow_caster_fp.glsl
+shadow_caster_ignore_heightmap_fp.glsl
 shadow_caster_vp.glsl
 StdQuad_vp.glsl
 spotlight_shadow_demo_fp.glsl

media/materials/programs/shadow_caster_ignore_heightmap_fp.glsl

@@ -0,0 +1,25 @@
+uniform vec4 camera_position;
+uniform mat4 world_matrix;
+
+// uniform vec4 depth_range;
+varying vec4 vertex_depth;
+
+void main()
+{
+  float depth = (vertex_depth.z) / vertex_depth.w;
+
+  // Linear
+  // float depth = (vertex_depth.z - depth_range.x) / depth_range.w;
+
+  vec4 magicVector1 = vec4(1.0, 0.0, 0.0, 0.0);
+  vec4 magicVector2 = vec4(0.0, 1.0, 0.0, 0.0);
+  vec4 magicVector3 = vec4(0.0, 0.0, 1.0, 0.0);
+
+  bool matchingVectors = (magicVector1 == world_matrix[0] && magicVector2 == world_matrix[1] && magicVector3 == world_matrix[2]);
+
+  if (length(camera_position.xyz) == 0 && matchingVectors) {
+    depth = 1.0;
+  }
+
+  gl_FragColor = vec4(depth, depth, depth, 1.0);
+}

media/materials/scripts/CMakeLists.txt

@@ -20,6 +20,7 @@ perpixel.program
 picker.material
 ShadowCaster.material
 shadow_caster.program
+shadow_caster_ignore_heightmap.program
 ShadowCaster.program
 spotlight_shadow_demo.material
 ssao.compositor

media/materials/scripts/shadow_caster_ignore_heightmap.program

@@ -0,0 +1,41 @@
+vertex_program shadow_caster_vp_glsl glsl
+{
+  source shadow_caster_vp.glsl
+
+  default_params
+  {
+    param_named_auto world_view_proj_mat worldviewproj_matrix
+    param_named_auto texel_offsets texel_offsets
+  }
+}
+
+fragment_program shadow_caster_ignore_heightmap_fp_glsl glsl
+{
+  source shadow_caster_ignore_heightmap_fp.glsl
+
+  default_params
+  {
+    param_named_auto camera_position camera_position
+    param_named_auto world_matrix world_matrix
+    // param_named_auto depth_range shadow_scene_depth_range
+  }
+}
+
+
+material Gazebo/shadow_caster_ignore_heightmap
+{
+  technique
+  {
+    // all this will do is write depth and depth*depth to red and green
+    pass
+    {
+      vertex_program_ref shadow_caster_vp_glsl
+      {
+      }
+
+      fragment_program_ref shadow_caster_ignore_heightmap_fp_glsl
+      {
+      }
+    }
+  }
+}

test/integration/CMakeLists.txt

@@ -130,6 +130,13 @@ if (NOT WIN32)
   )
 endif()
 
+if (NOT APPLE)
+  set(tests
+    ${tests}
+    custom_shadow_caster.cc
+  )
+endif()
+
 if (HAVE_GTS)
   set(tests
     ${tests}