Make rigidbody simulation handle animated objects gracefully

The animated objects was not updated for each internal substep for the rigidbody sim.
This would lead to unstable simulations or very annoying clipping artifacts.

Updated the code to use explicit substeps and tie it to the scene frame rate.

Fix T47402: Properly updating the animated objects fixes the reported issue.

Reviewed By: Brecht, Jacques

Differential Revision: http://developer.blender.org/D8762

5 files changed, 144 insertions, 2 deletions

diff --git a/intern/rigidbody/CMakeLists.txt b/intern/rigidbody/CMakeLists.txt
index 77d88548e1b..91cfc312bd2 100644
--- a/intern/rigidbody/CMakeLists.txt
+++ b/intern/rigidbody/CMakeLists.txt
@@ -18,6 +18,8 @@
 # All rights reserved.
 # ***** END GPL LICENSE BLOCK *****
 
+add_definitions(-DBT_USE_DOUBLE_PRECISION)
+
 set(INC
   .
 )
@@ -28,7 +30,9 @@ set(INC_SYS
 
 set(SRC
   rb_bullet_api.cpp
+  rb_convex_hull_api.cpp
 
+  RBI_hull_api.h
   RBI_api.h
 )
 
diff --git a/intern/rigidbody/RBI_api.h b/intern/rigidbody/RBI_api.h
index 07cda49e04b..2e09f8952cb 100644
--- a/intern/rigidbody/RBI_api.h
+++ b/intern/rigidbody/RBI_api.h
@@ -200,10 +200,12 @@ void RB_body_set_scale(rbRigidBody *body, const float scale[3]);
 
 /* ............ */
 
-/* Get RigidBody's position as vector */
+/* Get RigidBody's position as a vector */
 void RB_body_get_position(rbRigidBody *body, float v_out[3]);
-/* Get RigidBody's orientation as quaternion */
+/* Get RigidBody's orientation as a quaternion */
 void RB_body_get_orientation(rbRigidBody *body, float v_out[4]);
+/* Get RigidBody's local scale as a vector */
+void RB_body_get_scale(rbRigidBody *object, float v_out[3]);
 
 /* ............ */
 
diff --git a/intern/rigidbody/RBI_hull_api.h b/intern/rigidbody/RBI_hull_api.h
new file mode 100644
index 00000000000..9d2dc5034db
--- /dev/null
+++ b/intern/rigidbody/RBI_hull_api.h
@@ -0,0 +1,43 @@
+/*
+ * 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.
+ *
+ * The Original Code is Copyright (C) 2020 Blender Foundation,
+ * All rights reserved.
+ */
+
+#ifndef __RB_HULL_API_H__
+#define __RB_HULL_API_H__
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct plConvexHull__ {
+  int unused;
+} * plConvexHull;
+
+plConvexHull plConvexHullCompute(float (*coords)[3], int count);
+void plConvexHullDelete(plConvexHull hull);
+int plConvexHullNumVertices(plConvexHull hull);
+int plConvexHullNumFaces(plConvexHull hull);
+void plConvexHullGetVertex(plConvexHull hull, int n, float coords[3], int *original_index);
+int plConvexHullGetFaceSize(plConvexHull hull, int n);
+void plConvexHullGetFaceVertices(plConvexHull hull, int n, int *vertices);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __RB_HULL_API_H__ */
diff --git a/intern/rigidbody/rb_bullet_api.cpp b/intern/rigidbody/rb_bullet_api.cpp
index b5814055cf8..daa377a7b55 100644
--- a/intern/rigidbody/rb_bullet_api.cpp
+++ b/intern/rigidbody/rb_bullet_api.cpp
@@ -649,6 +649,16 @@ void RB_body_get_orientation(rbRigidBody *object, float v_out[4])
   copy_quat_btquat(v_out, body->getWorldTransform().getRotation());
 }
 
+void RB_body_get_scale(rbRigidBody *object, float v_out[3])
+{
+  btRigidBody *body = object->body;
+
+  btCollisionShape *cshape = body->getCollisionShape();
+  /* The body should have a collision shape when we try to set the scale. */
+  btAssert(cshape);
+  copy_v3_btvec3(v_out, cshape->getLocalScaling());
+}
+
 /* ............ */
 /* Overrides for simulation */
 
diff --git a/intern/rigidbody/rb_convex_hull_api.cpp b/intern/rigidbody/rb_convex_hull_api.cpp
new file mode 100644
index 00000000000..c5893a4c808
--- /dev/null
+++ b/intern/rigidbody/rb_convex_hull_api.cpp
@@ -0,0 +1,83 @@
+/*
+ * 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.
+ *
+ * The Original Code is Copyright (C) 2020 Blender Foundation,
+ * All rights reserved.
+ */
+
+#include "LinearMath/btConvexHullComputer.h"
+#include "RBI_hull_api.h"
+
+plConvexHull plConvexHullCompute(float (*coords)[3], int count)
+{
+  btConvexHullComputer *computer = new btConvexHullComputer;
+  computer->compute(reinterpret_cast<float *>(coords), sizeof(*coords), count, 0, 0);
+  return reinterpret_cast<plConvexHull>(computer);
+}
+
+void plConvexHullDelete(plConvexHull hull)
+{
+  btConvexHullComputer *computer(reinterpret_cast<btConvexHullComputer *>(hull));
+  delete computer;
+}
+
+int plConvexHullNumVertices(plConvexHull hull)
+{
+  btConvexHullComputer *computer(reinterpret_cast<btConvexHullComputer *>(hull));
+  return computer->vertices.size();
+}
+
+int plConvexHullNumFaces(plConvexHull hull)
+{
+  btConvexHullComputer *computer(reinterpret_cast<btConvexHullComputer *>(hull));
+  return computer->faces.size();
+}
+
+void plConvexHullGetVertex(plConvexHull hull, int n, float coords[3], int *original_index)
+{
+  btConvexHullComputer *computer(reinterpret_cast<btConvexHullComputer *>(hull));
+  const btVector3 &v(computer->vertices[n]);
+  coords[0] = v[0];
+  coords[1] = v[1];
+  coords[2] = v[2];
+  (*original_index) = computer->original_vertex_index[n];
+}
+
+int plConvexHullGetFaceSize(plConvexHull hull, int n)
+{
+  btConvexHullComputer *computer(reinterpret_cast<btConvexHullComputer *>(hull));
+  const btConvexHullComputer::Edge *e_orig, *e;
+  int count;
+
+  for (e_orig = &computer->edges[computer->faces[n]], e = e_orig, count = 0;
+       count == 0 || e != e_orig;
+       e = e->getNextEdgeOfFace(), count++) {
+    ;
+  }
+  return count;
+}
+
+void plConvexHullGetFaceVertices(plConvexHull hull, int n, int *vertices)
+{
+  btConvexHullComputer *computer(reinterpret_cast<btConvexHullComputer *>(hull));
+  const btConvexHullComputer::Edge *e_orig, *e;
+  int count;
+
+  for (e_orig = &computer->edges[computer->faces[n]], e = e_orig, count = 0;
+       count == 0 || e != e_orig;
+       e = e->getNextEdgeOfFace(), count++) {
+    vertices[count] = e->getTargetVertex();
+  }
+}