1 files changed, 118 insertions, 0 deletions
diff --git a/source/blender/io/alembic/exporter/abc_writer_transform.cc b/source/blender/io/alembic/exporter/abc_writer_transform.cc
new file mode 100644
index 00000000000..39af99c142c
--- /dev/null
+++ b/source/blender/io/alembic/exporter/abc_writer_transform.cc
@@ -0,0 +1,118 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+/** \file
+ * \ingroup balembic
+ */
+
+#include "abc_writer_transform.h"
+#include "abc_hierarchy_iterator.h"
+#include "intern/abc_axis_conversion.h"
+#include "intern/abc_util.h"
+
+#include "BKE_object.h"
+
+#include "BLI_math_matrix.h"
+#include "BLI_math_rotation.h"
+
+#include "DNA_layer_types.h"
+
+#include "CLG_log.h"
+static CLG_LogRef LOG = {"io.alembic"};
+
+namespace blender {
+namespace io {
+namespace alembic {
+
+using Alembic::Abc::OObject;
+using Alembic::AbcGeom::OXform;
+using Alembic::AbcGeom::OXformSchema;
+using Alembic::AbcGeom::XformSample;
+
+ABCTransformWriter::ABCTransformWriter(const ABCWriterConstructorArgs &args)
+    : ABCAbstractWriter(args)
+{
+  timesample_index_ = args_.abc_archive->time_sampling_index_transforms();
+}
+
+void ABCTransformWriter::create_alembic_objects(const HierarchyContext * /*context*/)
+{
+  CLOG_INFO(&LOG, 2, "exporting %s", args_.abc_path.c_str());
+  abc_xform_ = OXform(args_.abc_parent, args_.abc_name, timesample_index_);
+  abc_xform_schema_ = abc_xform_.getSchema();
+}
+
+void ABCTransformWriter::do_write(HierarchyContext &context)
+{
+  float parent_relative_matrix[4][4];  // The object matrix relative to the parent.
+  mul_m4_m4m4(parent_relative_matrix, context.parent_matrix_inv_world, context.matrix_world);
+
+  // After this, parent_relative_matrix uses Y=up.
+  copy_m44_axis_swap(parent_relative_matrix, parent_relative_matrix, ABC_YUP_FROM_ZUP);
+
+  /* If the parent is a camera, undo its to-Maya rotation (see below). */
+  bool is_root_object = context.export_parent == nullptr;
+  if (!is_root_object && context.export_parent->type == OB_CAMERA) {
+    float rot_mat[4][4];
+    axis_angle_to_mat4_single(rot_mat, 'X', M_PI_2);
+    mul_m4_m4m4(parent_relative_matrix, rot_mat, parent_relative_matrix);
+  }
+
+  /* If the object is a camera, apply an extra rotation to Maya camera orientation. */
+  if (context.object->type == OB_CAMERA) {
+    float rot_mat[4][4];
+    axis_angle_to_mat4_single(rot_mat, 'X', -M_PI_2);
+    mul_m4_m4m4(parent_relative_matrix, parent_relative_matrix, rot_mat);
+  }
+
+  if (is_root_object) {
+    /* Only apply scaling to root objects, parenting will propagate it. */
+    float scale_mat[4][4];
+    scale_m4_fl(scale_mat, args_.export_params->global_scale);
+    scale_mat[3][3] = args_.export_params->global_scale; /* also scale translation */
+    mul_m4_m4m4(parent_relative_matrix, parent_relative_matrix, scale_mat);
+    parent_relative_matrix[3][3] /=
+        args_.export_params->global_scale; /* normalise the homogeneous component */
+  }
+
+  XformSample xform_sample;
+  xform_sample.setMatrix(convert_matrix_datatype(parent_relative_matrix));
+  xform_sample.setInheritsXforms(true);
+  abc_xform_schema_.set(xform_sample);
+}
+
+const OObject ABCTransformWriter::get_alembic_object() const
+{
+  return abc_xform_;
+}
+
+bool ABCTransformWriter::check_is_animated(const HierarchyContext &context) const
+{
+  if (context.duplicator != NULL) {
+    /* This object is being duplicated, so could be emitted by a particle system and thus
+     * influenced by forces. TODO(Sybren): Make this more strict. Probably better to get from the
+     * depsgraph whether this object instance has a time source. */
+    return true;
+  }
+  if (check_has_physics(context)) {
+    return true;
+  }
+  return BKE_object_moves_in_time(context.object, context.animation_check_include_parent);
+}
+
+}  // namespace alembic
+}  // namespace io
+}  // namespace blender