Camera tracking: added depth object to Follow Track constraint

If this object is defined, object with Follow Track constraint would be
projected into surface of this depth object.
If object is not set or there's no projection onto it, projection plane
calculated based on original object position would be used.

This allows to make cheap facial mocap.

4 files changed, 75 insertions, 5 deletions

diff --git a/source/blender/blenkernel/intern/constraint.c b/source/blender/blenkernel/intern/constraint.c
index 878db6b3ed1..77a4a6a429c 100644
--- a/source/blender/blenkernel/intern/constraint.c
+++ b/source/blender/blenkernel/intern/constraint.c
@@ -41,6 +41,7 @@
 #include "BLI_blenlib.h"
 #include "BLI_math.h"
 #include "BLI_editVert.h"
+#include "BLI_kdopbvh.h"
 #include "BLI_utildefines.h"
 
 #include "DNA_armature_types.h"
@@ -64,6 +65,7 @@
 #include "BKE_anim.h" /* for the curve calculation part */
 #include "BKE_armature.h"
 #include "BKE_blender.h"
+#include "BKE_bvhutils.h"
 #include "BKE_camera.h"
 #include "BKE_constraint.h"
 #include "BKE_displist.h"
@@ -3950,6 +3952,7 @@ static void followtrack_id_looper (bConstraint *con, ConstraintIDFunc func, void
 	
 	func(con, (ID**)&data->clip, userdata);
 	func(con, (ID**)&data->camera, userdata);
+	func(con, (ID**)&data->depth_ob, userdata);
 }
 
 static void followtrack_evaluate (bConstraint *con, bConstraintOb *cob, ListBase *UNUSED(targets))
@@ -3985,7 +3988,6 @@ static void followtrack_evaluate (bConstraint *con, bConstraintOb *cob, ListBase
 
 	if (data->flag & FOLLOWTRACK_USE_3D_POSITION) {
 		if (track->flag & TRACK_HAS_BUNDLE) {
-			MovieTracking *tracking= &clip->tracking;
 			float obmat[4][4], mat[4][4];
 
 			copy_m4_m4(obmat, cob->matrix);
@@ -4008,9 +4010,8 @@ static void followtrack_evaluate (bConstraint *con, bConstraintOb *cob, ListBase
 				translate_m4(cob->matrix, track->bundle_pos[0], track->bundle_pos[1], track->bundle_pos[2]);
 			}
 		}
-	} 
+	}
 	else {
-		MovieClipUser user;
 		MovieTrackingMarker *marker;
 		float vec[3], disp[3], axis[3], mat[4][4];
 		float aspect= (scene->r.xsch*scene->r.xasp) / (scene->r.ysch*scene->r.yasp);
@@ -4035,8 +4036,7 @@ static void followtrack_evaluate (bConstraint *con, bConstraintOb *cob, ListBase
 			CameraParams params;
 			float pos[2], rmat[4][4];
 
-			user.framenr= scene->r.cfra;
-			marker= BKE_tracking_get_marker(track, user.framenr);
+			marker= BKE_tracking_get_marker(track, scene->r.cfra);
 
 			add_v2_v2v2(pos, marker->pos, track->offset);
 
@@ -4078,6 +4078,34 @@ static void followtrack_evaluate (bConstraint *con, bConstraintOb *cob, ListBase
 
 				copy_v3_v3(cob->matrix[3], disp);
 			}
+
+			if(data->depth_ob && data->depth_ob->derivedFinal) {
+				Object *depth_ob= data->depth_ob;
+				BVHTreeFromMesh treeData= NULL_BVHTreeFromMesh;
+				BVHTreeRayHit hit;
+				float ray_start[3], ray_end[3], ray_nor[3], imat[4][4];
+				int result;
+
+				invert_m4_m4(imat, depth_ob->obmat);
+
+				mul_v3_m4v3(ray_start, imat, camob->obmat[3]);
+				mul_v3_m4v3(ray_end, imat, cob->matrix[3]);
+
+				sub_v3_v3v3(ray_nor, ray_end, ray_start);
+
+				bvhtree_from_mesh_faces(&treeData, depth_ob->derivedFinal, 0.0f, 4, 6);
+
+				hit.dist= FLT_MAX;
+				hit.index= -1;
+
+				result= BLI_bvhtree_ray_cast(treeData.tree, ray_start, ray_nor, 0.0f, &hit, treeData.raycast_callback, &treeData);
+
+				if(result != -1) {
+					mul_v3_m4v3(cob->matrix[3], depth_ob->obmat, hit.co);
+				}
+
+				free_bvhtree_from_mesh(&treeData);
+			}
 		}
 	}
 }
diff --git a/source/blender/blenkernel/intern/depsgraph.c b/source/blender/blenkernel/intern/depsgraph.c
index 3cb2f8ce738..762aaf3efc1 100644
--- a/source/blender/blenkernel/intern/depsgraph.c
+++ b/source/blender/blenkernel/intern/depsgraph.c
@@ -657,6 +657,11 @@ static void build_dag_object(DagForest *dag, DagNode *scenenode, Scene *scene, O
 
 				if((data->clip || data->flag&FOLLOWTRACK_ACTIVECLIP) && data->track[0])
 					depends_on_camera= 1;
+
+				if(data->depth_ob) {
+					node2 = dag_get_node(dag, data->depth_ob);
+					dag_add_relation(dag, node2, node, DAG_RL_DATA_OB|DAG_RL_OB_OB, cti->name);
+				}
 			}
 			else if(cti->type==CONSTRAINT_TYPE_OBJECTSOLVER)
 				depends_on_camera= 1;
diff --git a/source/blender/makesdna/DNA_constraint_types.h b/source/blender/makesdna/DNA_constraint_types.h
index 8fdbde60bab..c829d5be294 100644
--- a/source/blender/makesdna/DNA_constraint_types.h
+++ b/source/blender/makesdna/DNA_constraint_types.h
@@ -417,6 +417,7 @@ typedef struct bFollowTrackConstraint {
 	int		flag, pad;
 	char		object[24];
 	struct Object *camera;
+	struct Object *depth_ob;
 } bFollowTrackConstraint;
 
 /* Camera Solver constraints */
diff --git a/source/blender/makesrna/intern/rna_constraint.c b/source/blender/makesrna/intern/rna_constraint.c
index 6439d22e808..3258b8c3dcb 100644
--- a/source/blender/makesrna/intern/rna_constraint.c
+++ b/source/blender/makesrna/intern/rna_constraint.c
@@ -358,6 +358,34 @@ static void rna_Constraint_followTrack_camera_set(PointerRNA *ptr, PointerRNA va
 	}
 }
 
+static void rna_Constraint_followTrack_depthObject_set(PointerRNA *ptr, PointerRNA value)
+{
+	bConstraint *con= (bConstraint*)ptr->data;
+	bFollowTrackConstraint *data= (bFollowTrackConstraint*)con->data;
+	Object *ob= (Object*)value.data;
+
+	if (ob) {
+		if (ob->type == OB_MESH && ob != (Object*)ptr->id.data) {
+			data->depth_ob= ob;
+		}
+	} else {
+		data->depth_ob= NULL;
+	}
+}
+
+static int rna_Constraint_followTrack_depthObject_poll(PointerRNA *ptr, PointerRNA value)
+{
+	Object *ob= (Object*)value.data;
+
+	if(ob) {
+		if (ob->type == OB_MESH && ob != (Object*)ptr->id.data) {
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
 static void rna_Constraint_objectSolver_camera_set(PointerRNA *ptr, PointerRNA value)
 {
 	bConstraint *con= (bConstraint*)ptr->data;
@@ -2126,6 +2154,14 @@ static void rna_def_constraint_follow_track(BlenderRNA *brna)
 	RNA_def_property_flag(prop, PROP_EDITABLE);
 	RNA_def_property_update(prop, NC_OBJECT|ND_CONSTRAINT, "rna_Constraint_dependency_update");
 	RNA_def_property_pointer_funcs(prop, NULL, "rna_Constraint_followTrack_camera_set", NULL, "rna_Constraint_cameraObject_poll");
+
+	/* depth object */
+	prop= RNA_def_property(srna, "depth_object", PROP_POINTER, PROP_NONE);
+	RNA_def_property_pointer_sdna(prop, NULL, "depth_ob");
+	RNA_def_property_ui_text(prop, "Depth Object", "Object used to define depth in camera space by projecting onto surface of this object");
+	RNA_def_property_flag(prop, PROP_EDITABLE);
+	RNA_def_property_update(prop, NC_OBJECT|ND_CONSTRAINT, "rna_Constraint_dependency_update");
+	RNA_def_property_pointer_funcs(prop, NULL, "rna_Constraint_followTrack_depthObject_set", NULL, "rna_Constraint_followTrack_depthObject_poll");
 }
 
 static void rna_def_constraint_camera_solver(BlenderRNA *brna)