Cycles: Improved robustness of hair motion blur.motion_curve_fix

In some instances, the number of control vertices of a hair could change mid-frame.
Cycles would then be unable to calculate proper motion blur for those hairs. This adds
interpolated CVs to fill in for the missing data. While this will not necessarily result in
a fully accurate reconstruction of the guide hair, it preserves motion blur instead of disabling it.

Reviewers: #cycles, sergey

Reviewed By: #cycles, sergey

Subscribers: sergey, brecht, #cycles

Tags: #cycles

Differential Revision: https://developer.blender.org/D3695

1 files changed, 8 insertions, 5 deletions

diff --git a/source/blender/blenkernel/intern/texture.c b/source/blender/blenkernel/intern/texture.c
index a0399c74be1..bd6199d91b4 100644
--- a/source/blender/blenkernel/intern/texture.c
+++ b/source/blender/blenkernel/intern/texture.c
@@ -548,12 +548,15 @@ Tex *BKE_texture_copy(Main *bmain, const Tex *tex)
 /* texture copy without adding to main dbase */
 Tex *BKE_texture_localize(Tex *tex)
 {
-	/* TODO replace with something like
-	 * 	Tex *tex_copy;
-	 * 	BKE_id_copy_ex(bmain, &tex->id, (ID **)&tex_copy, LIB_ID_COPY_NO_MAIN | LIB_ID_COPY_NO_PREVIEW | LIB_ID_COPY_NO_USER_REFCOUNT, false);
-	 * 	return tex_copy;
+	/* TODO(bastien): Replace with something like:
 	 *
-	 * ... Once f*** nodes are fully converted to that too :( */
+	 *   Tex *tex_copy;
+	 *   BKE_id_copy_ex(bmain, &tex->id, (ID **)&tex_copy,
+	 *                  LIB_ID_COPY_NO_MAIN | LIB_ID_COPY_NO_PREVIEW | LIB_ID_COPY_NO_USER_REFCOUNT,
+	 *                  false);
+	 *   return tex_copy;
+	 *
+	 * NOTE: Only possible once nested node trees are fully converted to that too. */
 
 	Tex *texn;