Added support for instances

Author: gboisse

RadeonRays/src/accelerator/bvh2.h

@@ -199,9 +199,13 @@ namespace RadeonRays
         std::size_t num_items = 0;
         for (auto iter = begin; iter != end; ++iter)
         {
+            auto shape = static_cast<const ShapeImpl *>(*iter);
+            auto mesh = static_cast<const Mesh *>(shape->is_instance() ? static_cast<const Instance *>(shape)->GetBaseShape() : shape);
+
             // Quads are deprecated and no longer supported
-            assert(static_cast<const Mesh *>(*iter)->puretriangle());
-            num_items += static_cast<const Mesh *>(*iter)->num_faces();
+            assert(mesh->puretriangle());
+
+            num_items += mesh->num_faces();
         }
 
         auto deleter = [](void *ptr) { Deallocate(ptr); };
@@ -234,12 +238,24 @@ namespace RadeonRays
         std::size_t current_face = 0;
         for (auto iter = begin; iter != end; ++iter)
         {
-            auto mesh = static_cast<const Mesh *>(*iter);
+            auto shape = static_cast<const ShapeImpl *>(*iter);
+            auto isinstance = shape->is_instance();
+            auto mesh = static_cast<const Mesh *>(isinstance ? static_cast<const Instance *>(shape)->GetBaseShape() : shape);
+
+            matrix m, minv;
+            shape->GetTransform(m, minv);
 
             for (std::size_t face_index = 0; face_index < mesh->num_faces(); ++face_index, ++current_face)
             {
                 bbox bounds;
-                mesh->GetFaceBounds(face_index, false, bounds);
+                mesh->GetFaceBounds(face_index, isinstance, bounds);
+
+                // Instance is using its own transform for base shape geometry
+                // so we need to get object space bounds and transform them manually
+                if(isinstance)
+                {
+                    bounds = transform_bbox(bounds, m);
+                }
 
                 auto pmin = _mm_set_ps(bounds.pmin.w, bounds.pmin.z, bounds.pmin.y, bounds.pmin.x);
                 auto pmax = _mm_set_ps(bounds.pmax.w, bounds.pmax.z, bounds.pmax.y, bounds.pmax.x);

RadeonRays/src/intersector/intersector_lds.cpp

@@ -177,18 +177,7 @@ namespace RadeonRays
 
             // Create the bvh
             Bvh2 bvh(traversal_cost, num_bins, use_sah);
-
-            // Partition the array into meshes and instances
-            std::vector<const Shape *> shapes(world.shapes_);
-
-            auto firstinst = std::partition(shapes.begin(), shapes.end(),
-                [&](Shape const* shape)
-                {
-                    return !static_cast<ShapeImpl const*>(shape)->is_instance();
-                });
-
-            // TODO: deal with the instance stuff (gboisse)
-            bvh.Build(shapes.begin(), firstinst);
+            bvh.Build(world.shapes_.begin(), world.shapes_.end());
 
             // Upload BVH data to GPU memory
             if (!use_qbvh)