Adds “align” option to snap to verts/edges/faces, for bones in Pose mode.

Have to use a ugly hack, as for pose bones, rotscale transform matrix is not always the same as translate one... :/

Adresses feature request [#30979] snapping: "align rotation with the snapping target" and pose-mode.

4 files changed, 36 insertions, 11 deletions

diff --git a/release/scripts/startup/bl_ui/space_view3d.py b/release/scripts/startup/bl_ui/space_view3d.py
index 6efbb99701a..b3ac9481931 100644
--- a/release/scripts/startup/bl_ui/space_view3d.py
+++ b/release/scripts/startup/bl_ui/space_view3d.py
@@ -93,7 +93,7 @@ class VIEW3D_HT_header(Header):
             if snap_element != 'INCREMENT':
                 row.prop(toolsettings, "snap_target", text="")
                 if obj:
-                    if obj.mode == 'OBJECT' and snap_element != 'VOLUME':
+                    if obj.mode in {'OBJECT','POSE'} and snap_element != 'VOLUME':
                         row.prop(toolsettings, "use_snap_align_rotation", text="")
                     elif obj.mode == 'EDIT':
                         row.prop(toolsettings, "use_snap_self", text="")
diff --git a/source/blender/editors/transform/transform.c b/source/blender/editors/transform/transform.c
index 8b472fd987f..5c605e02fd1 100644
--- a/source/blender/editors/transform/transform.c
+++ b/source/blender/editors/transform/transform.c
@@ -3035,12 +3035,16 @@ static void ElementRotation(TransInfo *t, TransData *td, float mat[3][3], short
 		}
 		
 		/* rotation */
-		if ((t->flag & T_V3D_ALIGN)==0) { // align mode doesn't rotate objects itself
+		/* MORE HACK: as in some cases the matrix to apply location and rot/scale is not the same,
+		 * and ElementRotation() might be called in Translation context (with align snapping),
+		 * we need to be sure to actually use the *rotation* matrix here...
+		 * So no other way than storing it in some dedicated members of td->ext! */
+		if ((t->flag & T_V3D_ALIGN)==0) { /* align mode doesn't rotate objects itself */
 			/* euler or quaternion/axis-angle? */
 			if (td->ext->rotOrder == ROT_MODE_QUAT) {
-				mul_serie_m3(fmat, td->mtx, mat, td->smtx, NULL, NULL, NULL, NULL, NULL);
+				mul_serie_m3(fmat, td->ext->r_mtx, mat, td->ext->r_smtx, NULL, NULL, NULL, NULL, NULL);
 				
-				mat3_to_quat(quat, fmat);	// Actual transform
+				mat3_to_quat(quat, fmat); /* Actual transform */
 				
 				mul_qt_qtqt(td->ext->quat, quat, td->ext->iquat);
 				/* this function works on end result */
@@ -3053,8 +3057,8 @@ static void ElementRotation(TransInfo *t, TransData *td, float mat[3][3], short
 				
 				axis_angle_to_quat(iquat, td->ext->irotAxis, td->ext->irotAngle);
 				
-				mul_serie_m3(fmat, td->mtx, mat, td->smtx, NULL, NULL, NULL, NULL, NULL);
-				mat3_to_quat(quat, fmat);	// Actual transform
+				mul_serie_m3(fmat, td->ext->r_mtx, mat, td->ext->r_smtx, NULL, NULL, NULL, NULL, NULL);
+				mat3_to_quat(quat, fmat); /* Actual transform */
 				mul_qt_qtqt(tquat, quat, iquat);
 				
 				quat_to_axis_angle(td->ext->rotAxis, td->ext->rotAngle, tquat);
@@ -3065,8 +3069,8 @@ static void ElementRotation(TransInfo *t, TransData *td, float mat[3][3], short
 			else { 
 				float eulmat[3][3];
 				
-				mul_m3_m3m3(totmat, mat, td->mtx);
-				mul_m3_m3m3(smat, td->smtx, totmat);
+				mul_m3_m3m3(totmat, mat, td->ext->r_mtx);
+				mul_m3_m3m3(smat, td->ext->r_smtx, totmat);
 				
 				/* calculate the total rotatation in eulers */
 				copy_v3_v3(eul, td->ext->irot);
@@ -3472,12 +3476,18 @@ static void applyTranslation(TransInfo *t, float vec[3])
 		/* handle snapping rotation before doing the translation */
 		if (usingSnappingNormal(t)) {
 			if (validSnappingNormal(t)) {
-				float *original_normal = td->axismtx[2];
+				float *original_normal;
 				float axis[3];
 				float quat[4];
 				float mat[3][3];
 				float angle;
 				
+				/* In pose mode, we want to align normals with Y axis of bones... */
+				if (t->flag & T_POSE)
+					original_normal = td->axismtx[1];
+				else
+					original_normal = td->axismtx[2];
+				
 				cross_v3_v3v3(axis, original_normal, t->tsnap.snapNormal);
 				angle = saacos(dot_v3v3(original_normal, t->tsnap.snapNormal));
 				
diff --git a/source/blender/editors/transform/transform.h b/source/blender/editors/transform/transform.h
index c7cb7b179ae..f902659a5c5 100644
--- a/source/blender/editors/transform/transform.h
+++ b/source/blender/editors/transform/transform.h
@@ -137,6 +137,10 @@ typedef struct TransDataExtension {
 	float  isize[3];	 /* Initial size                                                                   */
 	float  obmat[4][4];	 /* Object matrix */
 	float  l_smtx[3][3]; /* use instead of td->smtx, It is the same but without the 'bone->bone_mat', see TD_PBONE_LOCAL_MTX_C */
+	float  r_mtx[3][3];  /* The rotscale matrix of pose bone, to allow using snap-align in translation mode,
+	                      * when td->mtx is the loc pose bone matrix (and hence can't be used to apply rotation in some cases,
+	                      * namely when a bone is in "NoLocal" or "Hinge" mode)... */
+	float  r_smtx[3][3]; /* Invers of previous one. */
 	int    rotOrder;	/* rotation mode,  as defined in eRotationModes (DNA_action_types.h) */
 } TransDataExtension;
 
diff --git a/source/blender/editors/transform/transform_conversions.c b/source/blender/editors/transform/transform_conversions.c
index b457d22a712..c4db85420ca 100644
--- a/source/blender/editors/transform/transform_conversions.c
+++ b/source/blender/editors/transform/transform_conversions.c
@@ -538,6 +538,7 @@ static void add_pose_transdata(TransInfo *t, bPoseChannel *pchan, Object *ob, Tr
 	/* New code, using "generic" BKE_pchan_to_pose_mat(). */
 	{
 		float rotscale_mat[4][4], loc_mat[4][4];
+		float rpmat[3][3];
 
 		BKE_pchan_to_pose_mat(pchan, rotscale_mat, loc_mat);
 		if (t->mode == TFM_TRANSLATION)
@@ -545,13 +546,23 @@ static void add_pose_transdata(TransInfo *t, bPoseChannel *pchan, Object *ob, Tr
 		else
 			copy_m3_m4(pmat, rotscale_mat);
 
+		/* Grrr! Exceptional case: When translating pose bones that are either Hinge or NoLocal,
+		 * and want align snapping, we just need both loc_mat and rotscale_mat.
+		 * So simply always store rotscale mat in td->ext, and always use it to apply rotations...
+		 * Ugly to need such hacks! :/ */
+		copy_m3_m4(rpmat, rotscale_mat);
+
 		if (constraints_list_needinv(t, &pchan->constraints)) {
 			copy_m3_m4(tmat, pchan->constinv);
 			invert_m3_m3(cmat, tmat);
 			mul_serie_m3(td->mtx, pmat, omat, cmat, NULL, NULL, NULL, NULL, NULL);
+			mul_serie_m3(td->ext->r_mtx, rpmat, omat, cmat, NULL,NULL,NULL,NULL,NULL);
 		}
-		else
-			mul_serie_m3(td->mtx, pmat, omat, NULL, NULL, NULL, NULL, NULL, NULL);
+		else {
+			mul_serie_m3(td->mtx, pmat, omat, NULL, NULL,NULL,NULL,NULL,NULL);
+			mul_serie_m3(td->ext->r_mtx, rpmat, omat, NULL, NULL,NULL,NULL,NULL,NULL);
+		}
+		invert_m3_m3(td->ext->r_smtx, td->ext->r_mtx);
 	}
 
 	invert_m3_m3(td->smtx, td->mtx);