USD to SDF: Added Lights attached to models (#903)

Signed-off-by: ahcorde <ahcorde@gmail.com>
Co-authored-by: Ashton Larkin <42042756+adlarkin@users.noreply.github.com>

Author: ahcorde

test/usd/upAxisZ.usda

@@ -121,6 +121,18 @@ def Xform "box" (
                 uniform token[] xformOpOrder = ["xformOp:scale"]
             }
         }
+
+        def DiskLight "boxModelLight" (
+            prepend apiSchemas = ["ShapingAPI"]
+            kind = "model"
+        )
+        {
+            float inputs:intensity = 3000
+            float inputs:specular = 0.5
+            float3 xformOp:rotateZYX = (0, 0, 45)
+            float3 xformOp:translate = (0, 0, 1000)
+            uniform token[] xformOpOrder = ["xformOp:translate", "xformOp:rotateZYX"]
+        }
     }
 }
 

usd/src/usd_parser/USDStage_TEST.cc

@@ -39,7 +39,7 @@ TEST(USDStage, Constructor)
 
     EXPECT_EQ("Z", stage.UpAxis());
     EXPECT_DOUBLE_EQ(0.01, stage.MetersPerUnit());
-    EXPECT_EQ(25u, stage.USDPaths().size());
+    EXPECT_EQ(26u, stage.USDPaths().size());
   }
 
   // Check up Axis equal to Y and metersPerUnit

usd/src/usd_parser/USDWorld.cc

@@ -23,6 +23,7 @@
 #include <utility>
 #include <vector>
 
+#include <ignition/common/Filesystem.hh>
 #include <ignition/common/Util.hh>
 
 #pragma push_macro ("__DEPRECATED")
@@ -174,20 +175,6 @@ namespace usd
         }
       }
 
-      if (prim.IsA<pxr::UsdLuxBoundableLightBase>() ||
-          prim.IsA<pxr::UsdLuxNonboundableLightBase>())
-      {
-        auto light = ParseUSDLights(prim, usdData, linkName);
-        light->SetName(primName);
-        if (light)
-        {
-          _world.AddLight(light.value());
-          // TODO(ahcorde) Include lights which are inside links
-        }
-        continue;
-      }
-      // TODO(anyone) support converting other USD light types
-
       sdf::Model *modelPtr = nullptr;
       if (!currentModelName.empty())
       {
@@ -202,6 +189,40 @@ namespace usd
         }
       }
 
+      if (prim.IsA<pxr::UsdLuxBoundableLightBase>() ||
+          prim.IsA<pxr::UsdLuxNonboundableLightBase>())
+      {
+        auto light = ParseUSDLights(prim, usdData, linkName);
+        if (light)
+        {
+          light->SetName(primName);
+
+          // assume this light belongs to the world unless the corresponding
+          // model/link for this light are found
+          bool worldLight = true;
+
+          // if the light prim we are parsing has no parent (or if its parent
+          // is the root prim), this means the light belongs to the world
+          const bool noModelAncestor = !prim.GetParent() ||
+            (prim.GetParent().GetName().GetString() == "/");
+          if (!noModelAncestor && modelPtr)
+          {
+            if (auto link =
+                modelPtr->LinkByName(ignition::common::basename(linkName)))
+            {
+              link->AddLight(light.value());
+              worldLight = false;
+            }
+          }
+
+          if (worldLight)
+          {
+            _world.AddLight(light.value());
+          }
+        }
+        continue;
+      }
+
       if (prim.IsA<pxr::UsdPhysicsJoint>())
       {
         if (!modelPtr)

usd/src/usd_parser/usd2sdf_TEST.cc

@@ -25,6 +25,8 @@
 
 #include <ignition/utils/ExtraTestMacros.hh>
 
+#include "sdf/Light.hh"
+#include "sdf/Link.hh"
 #include "sdf/Model.hh"
 #include "sdf/Root.hh"
 #include "sdf/World.hh"
@@ -121,6 +123,16 @@ TEST(check_cmd, IGN_UTILS_TEST_DISABLED_ON_WIN32(SDF))
     EXPECT_EQ(
       "ignition-gazebo-scene-broadcaster-system", plugins[3].Filename());
 
+    // the world should have lights attached to it
+    std::set<std::string> savedLightNames;
+    for (unsigned int i = 0; i < world->LightCount(); ++i)
+      savedLightNames.insert(world->LightByIndex(i)->Name());
+    EXPECT_EQ(3u, savedLightNames.size());
+
+    EXPECT_NE(savedLightNames.end(), savedLightNames.find("defaultLight"));
+    EXPECT_NE(savedLightNames.end(), savedLightNames.find("diskLight"));
+    EXPECT_NE(savedLightNames.end(), savedLightNames.find("sun"));
+
     // make sure all models in the USD file were correctly parsed to SDF
     std::set<std::string> savedModelNames;
     for (unsigned int i = 0; i < world->ModelCount(); ++i)
@@ -140,20 +152,29 @@ TEST(check_cmd, IGN_UTILS_TEST_DISABLED_ON_WIN32(SDF))
     ASSERT_NE(nullptr, world->ModelByName("box"));
     EXPECT_FALSE(world->ModelByName("box")->Static());
 
-    // check that models have the right links
-    std::function<void(const std::string &, const std::string &)> checkLink =
-      [&world](const std::string &_modelName, const std::string &_linkName)
+    // Check that models have the right links.
+    // If a link should have a light attached to it, check that as well
+    std::function<void(const std::string &, const std::string &,
+        const std::string &)> checkLink =
+      [&world](const std::string &_modelName, const std::string &_linkName,
+          const std::string &_lightLinkName)
       {
         const auto modelPtr = world->ModelByName(_modelName);
         ASSERT_NE(nullptr, modelPtr);
         EXPECT_EQ(1u, modelPtr->LinkCount());
-        EXPECT_NE(nullptr, modelPtr->LinkByName(_linkName));
+        const auto modelLink = modelPtr->LinkByName(_linkName);
+        ASSERT_NE(nullptr, modelLink);
+
+        if (!_lightLinkName.empty())
+          EXPECT_NE(nullptr, modelLink->LightByName(_lightLinkName));
+        else
+          EXPECT_EQ(0u, modelLink->LightCount());
       };
-    checkLink("ground_plane", "link");
-    checkLink("box", "box_link");
-    checkLink("cylinder", "cylinder_link");
-    checkLink("sphere", "sphere_link");
-    checkLink("capsule", "capsule_link");
-    checkLink("ellipsoid", "ellipsoid_link");
+    checkLink("ground_plane", "link", "");
+    checkLink("box", "box_link", "boxModelLight");
+    checkLink("cylinder", "cylinder_link", "");
+    checkLink("sphere", "sphere_link", "");
+    checkLink("capsule", "capsule_link", "");
+    checkLink("ellipsoid", "ellipsoid_link", "");
   }
 }