From 050de1fb8e830ad9978eb5c1d956630d10b927a2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sybren=20A=2E=20St=C3=BCvel?= <sybren@blender.org>
Date: Tue, 28 Jul 2020 12:38:01 +0200
Subject: Fix T79263: Alembic, exported rigid body animation not moving

The root cause was that `BKE_object_moves_in_time()` incorrectly returns
`false` when an object is moved by the physics system.

This also fixes the same issue in the USD exporter.
---
 .../blender/io/alembic/exporter/abc_writer_transform.cc  |  3 +++
 .../blender/io/common/IO_abstract_hierarchy_iterator.h   |  7 +++++++
 .../io/common/intern/abstract_hierarchy_iterator.cc      | 16 ++++++++++++++++
 source/blender/io/usd/intern/usd_writer_transform.cc     |  3 +++
 4 files changed, 29 insertions(+)

(limited to 'source/blender/io')

diff --git a/source/blender/io/alembic/exporter/abc_writer_transform.cc b/source/blender/io/alembic/exporter/abc_writer_transform.cc
index 65d6b7c5b41..39af99c142c 100644
--- a/source/blender/io/alembic/exporter/abc_writer_transform.cc
+++ b/source/blender/io/alembic/exporter/abc_writer_transform.cc
@@ -107,6 +107,9 @@ bool ABCTransformWriter::check_is_animated(const HierarchyContext &context) cons
      * 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);
 }
 
diff --git a/source/blender/io/common/IO_abstract_hierarchy_iterator.h b/source/blender/io/common/IO_abstract_hierarchy_iterator.h
index a274847e109..d289d86b397 100644
--- a/source/blender/io/common/IO_abstract_hierarchy_iterator.h
+++ b/source/blender/io/common/IO_abstract_hierarchy_iterator.h
@@ -129,7 +129,14 @@ class AbstractHierarchyWriter {
   // but wasn't used while exporting the current frame (for example, a particle-instanced mesh of
   // which the particle is no longer alive).
  protected:
+  /* Return true if the data written by this writer changes over time.
+   * Note that this function assumes this is an object data writer. Transform writers should not
+   * call this but implement their own logic. */
   virtual bool check_is_animated(const HierarchyContext &context) const;
+
+  /* Helper functions for animation checks. */
+  static bool check_has_physics(const HierarchyContext &context);
+  static bool check_has_deforming_physics(const HierarchyContext &context);
 };
 
 /* Determines which subset of the writers actually gets to write. */
diff --git a/source/blender/io/common/intern/abstract_hierarchy_iterator.cc b/source/blender/io/common/intern/abstract_hierarchy_iterator.cc
index 8e66c069e18..fbefc8c8e7e 100644
--- a/source/blender/io/common/intern/abstract_hierarchy_iterator.cc
+++ b/source/blender/io/common/intern/abstract_hierarchy_iterator.cc
@@ -39,6 +39,7 @@
 #include "DNA_modifier_types.h"
 #include "DNA_object_types.h"
 #include "DNA_particle_types.h"
+#include "DNA_rigidbody_types.h"
 
 #include "DEG_depsgraph_query.h"
 
@@ -127,6 +128,9 @@ bool AbstractHierarchyWriter::check_is_animated(const HierarchyContext &context)
   if (BKE_key_from_object(object) != nullptr) {
     return true;
   }
+  if (check_has_deforming_physics(context)) {
+    return true;
+  }
 
   /* Test modifiers. */
   /* TODO(Sybren): replace this with a check on the depsgraph to properly check for dependency on
@@ -142,6 +146,18 @@ bool AbstractHierarchyWriter::check_is_animated(const HierarchyContext &context)
   return false;
 }
 
+bool AbstractHierarchyWriter::check_has_physics(const HierarchyContext &context)
+{
+  const RigidBodyOb *rbo = context.object->rigidbody_object;
+  return rbo != nullptr && rbo->type == RBO_TYPE_ACTIVE;
+}
+
+bool AbstractHierarchyWriter::check_has_deforming_physics(const HierarchyContext &context)
+{
+  const RigidBodyOb *rbo = context.object->rigidbody_object;
+  return rbo != nullptr && rbo->type == RBO_TYPE_ACTIVE && (rbo->flag & RBO_FLAG_USE_DEFORM) != 0;
+}
+
 AbstractHierarchyIterator::AbstractHierarchyIterator(Depsgraph *depsgraph)
     : depsgraph_(depsgraph), writers_(), export_subset_({true, true})
 {
diff --git a/source/blender/io/usd/intern/usd_writer_transform.cc b/source/blender/io/usd/intern/usd_writer_transform.cc
index 643f1a8f4b1..49983115455 100644
--- a/source/blender/io/usd/intern/usd_writer_transform.cc
+++ b/source/blender/io/usd/intern/usd_writer_transform.cc
@@ -58,6 +58,9 @@ bool USDTransformWriter::check_is_animated(const HierarchyContext &context) cons
      * 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);
 }
 
-- 
cgit v1.2.3