[Bf-blender-cvs] [d92863a] alembic_basic_io: Fix some hierarchical issues.

[Kévin Dietrich]

Commit: d92863a77153ecf6138ac42e3856cb975fd19301
Author: Kévin Dietrich
Date:   Mon Jul 4 08:25:22 2016 +0200
Branches: alembic_basic_io
https://developer.blender.org/rBd92863a77153ecf6138ac42e3856cb975fd19301

Fix some hierarchical issues.

This fixes the rare issue found in some Maya and Unity files, where an
object would still be scaled even though it has a parent which was
already scaled.

===================================================================

M	source/blender/alembic/intern/abc_object.cc
M	source/blender/alembic/intern/abc_util.cc
M	source/blender/alembic/intern/abc_util.h

===================================================================

diff --git a/source/blender/alembic/intern/abc_object.cc b/source/blender/alembic/intern/abc_object.cc
index ac80e08..ad275ba 100644
--- a/source/blender/alembic/intern/abc_object.cc
+++ b/source/blender/alembic/intern/abc_object.cc
@@ -131,7 +131,13 @@ AbcObjectReader::AbcObjectReader(const IObject &object, ImportSettings &settings
 	std::vector<std::string> parts;
 	split(m_name, '/', parts);
 
-	m_object_name = m_data_name = parts[parts.size() - 1];
+	if (parts.size() >= 2) {
+		m_object_name = parts[parts.size() - 2];
+		m_data_name = parts[parts.size() - 1];
+	}
+	else {
+		m_object_name = m_data_name = parts[parts.size() - 1];
+	}
 }
 
 AbcObjectReader::~AbcObjectReader()
@@ -150,13 +156,34 @@ Object *AbcObjectReader::object() const
 void AbcObjectReader::readObjectMatrix(const float time)
 {
 	IXform ixform;
+	bool has_alembic_parent = false;
 
+	/* Check that we have an empty object (locator, bone head/tail...).  */
 	if (IXform::matches(m_iobject.getMetaData())) {
 		ixform = IXform(m_iobject, Alembic::AbcGeom::kWrapExisting);
+
+		/* See comment below. */
+		has_alembic_parent = m_iobject.getParent().getParent().valid();
 	}
+	/* Check that we have an object with actual data. */
 	else if (IXform::matches(m_iobject.getParent().getMetaData())) {
 		ixform = IXform(m_iobject.getParent(), Alembic::AbcGeom::kWrapExisting);
+
+		/* This is a bit hackish, but we need to make sure that extra
+		 * transformations added to the matrix (rotation/scale) are only applied
+		 * to root objects. The way objects and their hierarchy are created will
+		 * need to be revisited at some point but for now this seems to do the
+		 * trick.
+		 *
+		 * Explanation of the trick:
+		 * The first getParent() will return this object's transformation matrix.
+		 * The second getParent() will get the parent of the transform, but this
+		 * might be the archive root ('/') which is valid, so we go passed it to
+		 * make sure that there is no parent.
+		 */
+		has_alembic_parent = m_iobject.getParent().getParent().getParent().valid();
 	}
+	/* Should not happen. */
 	else {
 		return;
 	}
@@ -171,7 +198,7 @@ void AbcObjectReader::readObjectMatrix(const float time)
 	Alembic::AbcGeom::XformSample xs;
 	schema.get(xs, sample_sel);
 
-	create_input_transform(sample_sel, ixform, m_object, m_object->obmat, m_settings->scale);
+	create_input_transform(sample_sel, ixform, m_object, m_object->obmat, m_settings->scale, has_alembic_parent);
 
 	invert_m4_m4(m_object->imat, m_object->obmat);
 
diff --git a/source/blender/alembic/intern/abc_util.cc b/source/blender/alembic/intern/abc_util.cc
index a9e11f9..89969dd 100644
--- a/source/blender/alembic/intern/abc_util.cc
+++ b/source/blender/alembic/intern/abc_util.cc
@@ -204,7 +204,7 @@ void create_transform_matrix(float r_mat[4][4])
 
 void create_input_transform(const Alembic::AbcGeom::ISampleSelector &sample_sel,
                             const Alembic::AbcGeom::IXform &ixform, Object *ob,
-                            float r_mat[4][4], float scale)
+                            float r_mat[4][4], float scale, bool has_alembic_parent)
 {
 
 	const Alembic::AbcGeom::IXformSchema &ixform_schema = ixform.getSchema();
@@ -230,7 +230,8 @@ void create_input_transform(const Alembic::AbcGeom::ISampleSelector &sample_sel,
 	if (ob->parent) {
 		mul_m4_m4m4(r_mat, ob->parent->obmat, r_mat);
 	}
-	else {
+	/* TODO(kevin) */
+	else if (!has_alembic_parent) {
 		/* Only apply scaling to root objects, parenting will propagate it. */
 		float scale_mat[4][4];
 		scale_m4_fl(scale_mat, scale);
diff --git a/source/blender/alembic/intern/abc_util.h b/source/blender/alembic/intern/abc_util.h
index 4cc91b5..b2ab046 100644
--- a/source/blender/alembic/intern/abc_util.h
+++ b/source/blender/alembic/intern/abc_util.h
@@ -52,7 +52,7 @@ bool begins_with(const TContainer &input, const TContainer &match)
 
 void create_input_transform(const Alembic::AbcGeom::ISampleSelector &sample_sel,
                             const Alembic::AbcGeom::IXform &ixform, Object *ob,
-                            float r_mat[4][4], float scale);
+                            float r_mat[4][4], float scale, bool has_alembic_parent = false);
 
 template <typename Schema>
 void get_min_max_time(const Schema &schema, chrono_t &min, chrono_t &max)