Allow OSG to recalculate terrain normals.

CMakeLists.txt

@@ -18,6 +18,9 @@ if(COMMAND cmake_policy)
 
    if(POLICY CMP0093)
        cmake_policy(SET CMP0093 NEW)
+       endif()	
+   if(POLICY CMP0072)
+       cmake_policy(SET CMP0072 NEW)
    endif()
 endif()
 

simgear/scene/material/EffectGeode.cxx

@@ -72,37 +72,40 @@ void EffectGeode::releaseGLObjects(osg::State* state) const
 // Generates tangent space vectors or other data from geom, as defined by effect
 void EffectGeode::runGenerators(osg::Geometry *geometry)
 {
-      if(geometry && _effect.valid()) {
+    if(geometry && _effect.valid()) {
         // Generate tangent vectors for the geometry
         osg::ref_ptr<osgUtil::TangentSpaceGenerator> tsg = new osgUtil::TangentSpaceGenerator;
-
+        tsg->generate(geometry,0);  
         // Generating only tangent vector should be enough
         // since the binormal is a cross product of normal and tangent
         // This saves a bit of memory & memory bandwidth!
         int n = _effect->getGenerator(Effect::TANGENT);
-        tsg->generate(geometry, 0);  // 0 is normal_unit, but I have no idea what that is!
+        if (n != -1 && !geometry->getVertexAttribArray(n)) {
-        if (n != -1 && !geometry->getVertexAttribArray(n))
 #if OSG_MIN_VERSION_REQUIRED(3,1,8)
-          geometry->setVertexAttribArray(n, tsg->getTangentArray(), osg::Array::BIND_PER_VERTEX);
+            geometry->setVertexAttribArray(n, tsg->getTangentArray(), osg::Array::BIND_PER_VERTEX);
 #else
-          geometry->setVertexAttribData(n, osg::Geometry::ArrayData(tsg->getTangentArray(), osg::Geometry::BIND_PER_VERTEX,GL_FALSE));
+            geometry->setVertexAttribData(n, osg::Geometry::ArrayData(tsg->getTangentArray(), osg::Geometry::BIND_PER_VERTEX,GL_FALSE));
 #endif
-
+        }
         n = _effect->getGenerator(Effect::BINORMAL);
         if (n != -1 && !geometry->getVertexAttribArray(n))
 #if OSG_MIN_VERSION_REQUIRED(3,1,8)
-          geometry->setVertexAttribArray(n, tsg->getBinormalArray(), osg::Array::BIND_PER_VERTEX);
+            geometry->setVertexAttribArray(n, tsg->getBinormalArray(), osg::Array::BIND_PER_VERTEX);
 #else
-          geometry->setVertexAttribData(n, osg::Geometry::ArrayData(tsg->getBinormalArray(), osg::Geometry::BIND_PER_VERTEX,GL_FALSE));
+            geometry->setVertexAttribData(n, osg::Geometry::ArrayData(tsg->getBinormalArray(), osg::Geometry::BIND_PER_VERTEX,GL_FALSE));
 #endif
 
         n = _effect->getGenerator(Effect::NORMAL);
-        if (n != -1 && !geometry->getVertexAttribArray(n))
+        if (n != -1 && !geometry->getVertexAttribArray(n)) {
+            // Provide the tsg-generated normals to the geometry
+            Vec4Array * new_normals = tsg->getNormalArray();
+            geometry->setNormalArray(new_normals,osg::Array::BIND_PER_VERTEX);
 #if OSG_MIN_VERSION_REQUIRED(3,1,8)
-          geometry->setVertexAttribArray(n, tsg->getNormalArray(), osg::Array::BIND_PER_VERTEX);
+            geometry->setVertexAttribArray(n, new_normals, osg::Array::BIND_PER_VERTEX);
 #else
-          geometry->setVertexAttribData(n, osg::Geometry::ArrayData(tsg->getNormalArray(), osg::Geometry::BIND_PER_VERTEX,GL_FALSE));
+            geometry->setVertexAttribData(n, osg::Geometry::ArrayData(new_normals, osg::Geometry::BIND_PER_VERTEX,GL_FALSE));
 #endif
+        }
     }
 }
 

simgear/scene/tgdb/SGTexturedTriangleBin.hxx

@@ -348,7 +348,7 @@ public:
     }
   }
 
-   void addRandomPoints(double coverage, 
+  void addRandomPoints(double coverage, 
                         double spacing,
                         osg::Texture2D* object_mask,
                         std::vector<std::pair<SGVec3f, float> >& points)
@@ -421,7 +421,9 @@ public:
     }
   }
 
-  osg::Geometry* buildGeometry(const TriangleVector& triangles, bool useVBOs) const
+  // If include_norms is true, normals from the input vertices are added to the geometry. If false,
+  // they should be generated during geometry initialisation.
+  osg::Geometry* buildGeometry(const TriangleVector& triangles, bool useVBOs, bool include_norms) const
   {
     // Do not build anything if there is nothing in here ...
     if (empty() || triangles.empty())
@@ -444,8 +446,10 @@ public:
     
     geometry->setDataVariance(osg::Object::STATIC);
     geometry->setVertexArray(vertices);
-    geometry->setNormalArray(normals);
+    if (include_norms) { 
-    geometry->setNormalBinding(osg::Geometry::BIND_PER_VERTEX);
+        geometry->setNormalArray(normals);
+        geometry->setNormalBinding(osg::Geometry::BIND_PER_VERTEX);
+    }
     geometry->setColorArray(colors);
     geometry->setColorBinding(osg::Geometry::BIND_OVERALL);
     if ( has_sec_tcs ) {
@@ -499,8 +503,8 @@ public:
     return geometry;
   }
 
-  osg::Geometry* buildGeometry(bool useVBOs) const
+  osg::Geometry* buildGeometry(bool useVBOs, bool include_norms) const
-  { return buildGeometry(getTriangles(), useVBOs); }
+  { return buildGeometry(getTriangles(), useVBOs, include_norms); }
   
   int getTextureIndex() const
   {

simgear/scene/tgdb/SGTileGeometryBin.hxx

@@ -275,7 +275,6 @@ public:
     //osg::Geode* geode = new osg::Geode;
     SGMaterialTriangleMap::const_iterator i;
     for (i = materialTriangleMap.begin(); i != materialTriangleMap.end(); ++i) {
-      osg::Geometry* geometry = i->second.buildGeometry(useVBOs);
       SGMaterial *mat = NULL;
       if (matcache) {
         mat = matcache->find(i->first);
@@ -288,8 +287,15 @@ public:
       } else {
         eg->setMaterial(NULL);
       }
-      eg->addDrawable(geometry);
+      // If effect requests normal generation, we do not include terragear
+      // normals in the geometry
+      bool include_normals = true;
+      int n = eg->getEffect()->getGenerator(Effect::NORMAL);
+      if (n != -1)
+        include_normals = false;
+      osg::Geometry* geometry = i->second.buildGeometry(useVBOs, include_normals);
       eg->runGenerators(geometry);  // Generate extra data needed by effect
+      eg->addDrawable(geometry);
       if (group) {
         group->addChild(eg);
       }