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, 16 insertions, 4 deletions

diff --git a/source/blender/editors/include/ED_view3d.h b/source/blender/editors/include/ED_view3d.h
index 82411ba7401..c21a6cccb2e 100644
--- a/source/blender/editors/include/ED_view3d.h
+++ b/source/blender/editors/include/ED_view3d.h
@@ -221,12 +221,15 @@ float ED_view3d_pixel_size_no_ui_scale(const struct RegionView3D *rv3d, const fl
 
 float ED_view3d_calc_zfac(const struct RegionView3D *rv3d, const float co[3], bool *r_flip);
 bool ED_view3d_clip_segment(const struct RegionView3D *rv3d, float ray_start[3], float ray_end[3]);
-bool ED_view3d_win_to_ray(
+bool ED_view3d_win_to_ray_clipped(
         const struct ARegion *ar, const struct View3D *v3d, const float mval[2],
         float ray_start[3], float ray_normal[3], const bool do_clip);
-bool ED_view3d_win_to_ray_ex(
+bool ED_view3d_win_to_ray_clipped_ex(
         const struct ARegion *ar, const struct View3D *v3d, const float mval[2],
         float r_ray_co[3], float r_ray_normal[3], float r_ray_start[3], bool do_clip);
+void ED_view3d_win_to_ray(
+        const struct ARegion *ar, const float mval[2],
+        float r_ray_start[3], float r_ray_normal[3]);
 void ED_view3d_global_to_vector(const struct RegionView3D *rv3d, const float coord[3], float vec[3]);
 void ED_view3d_win_to_3d(
         const struct View3D *v3d, const struct ARegion *ar,
@@ -236,11 +239,20 @@ void ED_view3d_win_to_3d_int(
         const struct View3D *v3d, const struct ARegion *ar,
         const float depth_pt[3], const int mval[2],
         float r_out[3]);
+bool ED_view3d_win_to_3d_on_plane(
+        const struct ARegion *ar,
+        const float plane[4], const float mval[2], const bool do_clip,
+        float r_out[3]);
+bool ED_view3d_win_to_3d_on_plane_int(
+        const struct ARegion *ar,
+        const float plane[4], const int mval[2], const bool do_clip,
+        float r_out[3]);
 void ED_view3d_win_to_delta(const struct ARegion *ar, const float mval[2], float out[3], const float zfac);
 void ED_view3d_win_to_origin(const struct ARegion *ar, const float mval[2], float out[3]);
 void ED_view3d_win_to_vector(const struct ARegion *ar, const float mval[2], float out[3]);
-bool ED_view3d_win_to_segment(const struct ARegion *ar, struct View3D *v3d, const float mval[2],
-                              float r_ray_start[3], float r_ray_end[3], const bool do_clip);
+bool ED_view3d_win_to_segment_clipped(
+        const struct ARegion *ar, struct View3D *v3d, const float mval[2],
+        float r_ray_start[3], float r_ray_end[3], const bool do_clip);
 void ED_view3d_ob_project_mat_get(const struct RegionView3D *v3d, struct Object *ob, float pmat[4][4]);
 void ED_view3d_ob_project_mat_get_from_obmat(const struct RegionView3D *rv3d, float obmat[4][4], float pmat[4][4]);
 void ED_view3d_unproject(struct bglMats *mats, float out[3], const float x, const float y, const float z);