Fix for Cycles particle motion blur hiding fix.

My mistake in modifying the patch.

1 files changed, 12 insertions, 3 deletions

diff --git a/intern/cycles/render/object.cpp b/intern/cycles/render/object.cpp
index 7024a8bcc79..5dbe2e4d6a1 100644
--- a/intern/cycles/render/object.cpp
+++ b/intern/cycles/render/object.cpp
@@ -55,9 +55,9 @@ Object::Object()
 	particle_system = NULL;
 	particle_index = 0;
 	bounds = BoundBox::empty;
-	motion.pre = transform_identity();
-	motion.mid = transform_identity();
-	motion.post = transform_identity();
+	motion.pre = transform_empty();
+	motion.mid = transform_empty();
+	motion.post = transform_empty();
 	use_motion = false;
 }
 
@@ -346,6 +346,15 @@ void ObjectManager::device_update_object_transform(UpdateObejctTransformState *s
 		Transform mtfm_pre = ob->motion.pre;
 		Transform mtfm_post = ob->motion.post;
 
+		/* In case of missing motion information for previous/next frame,
+		 * assume there is no motion. */
+		if(!ob->use_motion || mtfm_pre == transform_empty()) {
+			mtfm_pre = ob->tfm;
+		}
+		if(!ob->use_motion || mtfm_post == transform_empty()) {
+			mtfm_post = ob->tfm;
+		}
+
 		if(!mesh->attributes.find(ATTR_STD_MOTION_VERTEX_POSITION)) {
 			mtfm_pre = mtfm_pre * itfm;
 			mtfm_post = mtfm_post * itfm;