Add handles to control Curve3D tilt

editor/plugins/path_3d_editor_plugin.cpp

@@ -40,39 +40,29 @@
 #include "scene/gui/menu_button.h"
 #include "scene/resources/curve.h"
 
-static bool _is_in_handle(int p_id, int p_num_points) {
-	int t = (p_id + 1) % 2;
-	int idx = (p_id + 1) / 2;
-	// order of points is [out_0, out_1, in_1, out_2, in_2, ... out_n-1, in_n-1, in_n]
-	if (idx == 0) {
-		return false;
-	} else if (idx == (p_num_points - 1)) {
-		return true;
-	} else {
-		return (t == 1);
-	}
-}
-
 String Path3DGizmo::get_handle_name(int p_id, bool p_secondary) const {
 	Ref<Curve3D> c = path->get_curve();
 	if (c.is_null()) {
 		return "";
 	}
 
+	// Primary handles: position.
 	if (!p_secondary) {
 		return TTR("Curve Point #") + itos(p_id);
 	}
 
-	// (p_id + 1) Accounts for the first point only having an "out" handle
-	int idx = (p_id + 1) / 2;
-	String n = TTR("Curve Point #") + itos(idx);
-	if (_is_in_handle(p_id, c->get_point_count())) {
-		n += " In";
-	} else {
-		n += " Out";
+	// Secondary handles: in, out, tilt.
+	const HandleInfo info = _secondary_handles_info[p_id];
+	switch (info.type) {
+		case HandleType::HANDLE_TYPE_IN:
+			return TTR("Handle In #") + itos(info.point_idx);
+		case HandleType::HANDLE_TYPE_OUT:
+			return TTR("Handle Out #") + itos(info.point_idx);
+		case HandleType::HANDLE_TYPE_TILT:
+			return TTR("Handle Tilt #") + itos(info.point_idx);
 	}
 
-	return n;
+	return "";
 }
 
 Variant Path3DGizmo::get_handle_value(int p_id, bool p_secondary) const {
@@ -81,23 +71,27 @@ Variant Path3DGizmo::get_handle_value(int p_id, bool p_secondary) const {
 		return Variant();
 	}
 
+	// Primary handles: position.
 	if (!p_secondary) {
 		original = c->get_point_position(p_id);
 		return original;
 	}
 
-	// (p_id + 1) Accounts for the first point only having an "out" handle
-	int idx = (p_id + 1) / 2;
-
+	// Secondary handles: in, out, tilt.
+	const HandleInfo info = _secondary_handles_info[p_id];
 	Vector3 ofs;
-	if (_is_in_handle(p_id, c->get_point_count())) {
-		ofs = c->get_point_in(idx);
-	} else {
-		ofs = c->get_point_out(idx);
+	switch (info.type) {
+		case HandleType::HANDLE_TYPE_TILT:
+			return c->get_point_tilt(info.point_idx);
+		case HandleType::HANDLE_TYPE_IN:
+			ofs = c->get_point_in(info.point_idx);
+			break;
+		case HandleType::HANDLE_TYPE_OUT:
+			ofs = c->get_point_out(info.point_idx);
+			break;
 	}
 
-	original = ofs + c->get_point_position(idx);
-
+	original = ofs + c->get_point_position(info.point_idx);
 	return ofs;
 }
 
@@ -107,17 +101,17 @@ void Path3DGizmo::set_handle(int p_id, bool p_secondary, Camera3D *p_camera, con
 		return;
 	}
 
-	Transform3D gt = path->get_global_transform();
-	Transform3D gi = gt.affine_inverse();
-	Vector3 ray_from = p_camera->project_ray_origin(p_point);
-	Vector3 ray_dir = p_camera->project_ray_normal(p_point);
+	const Transform3D gt = path->get_global_transform();
+	const Transform3D gi = gt.affine_inverse();
+	const Vector3 ray_from = p_camera->project_ray_origin(p_point);
+	const Vector3 ray_dir = p_camera->project_ray_normal(p_point);
+	const Plane p = Plane(p_camera->get_transform().basis.get_column(2), gt.xform(original));
 
-	// Setting curve point positions
+	// Primary handles: position.
 	if (!p_secondary) {
-		const Plane p = Plane(p_camera->get_transform().basis.get_column(2), gt.xform(original));
-
 		Vector3 inters;
-
+		// Special cas for primary handle, the handle id equals control point id.
+		const int idx = p_id;
 		if (p.intersects_ray(ray_from, ray_dir, &inters)) {
 			if (Node3DEditor::get_singleton()->is_snap_enabled()) {
 				float snap = Node3DEditor::get_singleton()->get_translate_snap();
@@ -125,45 +119,74 @@ void Path3DGizmo::set_handle(int p_id, bool p_secondary, Camera3D *p_camera, con
 			}
 
 			Vector3 local = gi.xform(inters);
-			c->set_point_position(p_id, local);
+			c->set_point_position(idx, local);
 		}
 
 		return;
 	}
 
-	// (p_id + 1) Accounts for the first point only having an "out" handle
-	int idx = (p_id + 1) / 2;
-
-	Vector3 base = c->get_point_position(idx);
-
-	Plane p(p_camera->get_transform().basis.get_column(2), gt.xform(original));
-
-	Vector3 inters;
+	// Secondary handles: in, out, tilt.
+	const HandleInfo info = _secondary_handles_info[p_id];
+	switch (info.type) {
+		case HandleType::HANDLE_TYPE_OUT:
+		case HandleType::HANDLE_TYPE_IN: {
+			const int idx = info.point_idx;
+			const Vector3 base = c->get_point_position(idx);
+
+			Vector3 inters;
+			if (p.intersects_ray(ray_from, ray_dir, &inters)) {
+				if (!Path3DEditorPlugin::singleton->is_handle_clicked()) {
+					orig_in_length = c->get_point_in(idx).length();
+					orig_out_length = c->get_point_out(idx).length();
+					Path3DEditorPlugin::singleton->set_handle_clicked(true);
+				}
 
-	// Setting curve in/out positions
-	if (p.intersects_ray(ray_from, ray_dir, &inters)) {
-		if (!Path3DEditorPlugin::singleton->is_handle_clicked()) {
-			orig_in_length = c->get_point_in(idx).length();
-			orig_out_length = c->get_point_out(idx).length();
-			Path3DEditorPlugin::singleton->set_handle_clicked(true);
-		}
+				Vector3 local = gi.xform(inters) - base;
+				if (Node3DEditor::get_singleton()->is_snap_enabled()) {
+					float snap = Node3DEditor::get_singleton()->get_translate_snap();
+					local.snap(Vector3(snap, snap, snap));
+				}
 
-		Vector3 local = gi.xform(inters) - base;
-		if (Node3DEditor::get_singleton()->is_snap_enabled()) {
-			float snap = Node3DEditor::get_singleton()->get_translate_snap();
-			local.snap(Vector3(snap, snap, snap));
+				if (info.type == HandleType::HANDLE_TYPE_IN) {
+					c->set_point_in(idx, local);
+					if (Path3DEditorPlugin::singleton->mirror_angle_enabled()) {
+						c->set_point_out(idx, Path3DEditorPlugin::singleton->mirror_length_enabled() ? -local : (-local.normalized() * orig_out_length));
+					}
+				} else {
+					c->set_point_out(idx, local);
+					if (Path3DEditorPlugin::singleton->mirror_angle_enabled()) {
+						c->set_point_in(idx, Path3DEditorPlugin::singleton->mirror_length_enabled() ? -local : (-local.normalized() * orig_in_length));
+					}
+				}
+			}
+			break;
 		}
+		case HandleType::HANDLE_TYPE_TILT: {
+			const int idx = info.point_idx;
+			const Vector3 position = c->get_point_position(idx);
+			const Basis posture = c->get_point_baked_posture(idx);
+			const Vector3 tangent = -posture.get_column(2);
+			const Vector3 up = posture.get_column(1);
+			const Plane p_tilt = Plane(tangent, position);
+
+			Vector3 intersection;
+
+			if (p_tilt.intersects_ray(ray_from, ray_dir, &intersection)) {
+				Vector3 direction = intersection - position;
+				direction.normalize(); // FIXME: redundant?
+				real_t tilt_angle = up.signed_angle_to(direction, tangent);
+
+				if (Node3DEditor::get_singleton()->is_snap_enabled()) {
+					real_t snap = Node3DEditor::get_singleton()->get_rotate_snap();
+
+					tilt_angle = Math::rad_to_deg(tilt_angle) + snap * 0.5; // Else it won't reach +180.
+					tilt_angle -= Math::fmod(tilt_angle, snap);
+					tilt_angle = Math::deg_to_rad(tilt_angle);
+				}
 
-		if (_is_in_handle(p_id, c->get_point_count())) {
-			c->set_point_in(idx, local);
-			if (Path3DEditorPlugin::singleton->mirror_angle_enabled()) {
-				c->set_point_out(idx, Path3DEditorPlugin::singleton->mirror_length_enabled() ? -local : (-local.normalized() * orig_out_length));
-			}
-		} else {
-			c->set_point_out(idx, local);
-			if (Path3DEditorPlugin::singleton->mirror_angle_enabled()) {
-				c->set_point_in(idx, Path3DEditorPlugin::singleton->mirror_length_enabled() ? -local : (-local.normalized() * orig_in_length));
+				c->set_point_tilt(idx, tilt_angle);
 			}
+			break;
 		}
 	}
 }
@@ -176,54 +199,72 @@ void Path3DGizmo::commit_handle(int p_id, bool p_secondary, const Variant &p_res
 
 	EditorUndoRedoManager *ur = EditorUndoRedoManager::get_singleton();
 
+	// Primary handles: position.
 	if (!p_secondary) {
+		// Special cas for primary handle, the handle id equals control point id.
+		const int idx = p_id;
 		if (p_cancel) {
-			c->set_point_position(p_id, p_restore);
+			c->set_point_position(idx, p_restore);
 			return;
 		}
 		ur->create_action(TTR("Set Curve Point Position"));
-		ur->add_do_method(c.ptr(), "set_point_position", p_id, c->get_point_position(p_id));
-		ur->add_undo_method(c.ptr(), "set_point_position", p_id, p_restore);
+		ur->add_do_method(c.ptr(), "set_point_position", idx, c->get_point_position(idx));
+		ur->add_undo_method(c.ptr(), "set_point_position", idx, p_restore);
 		ur->commit_action();
 
 		return;
 	}
 
-	// (p_id + 1) Accounts for the first point only having an "out" handle
-	int idx = (p_id + 1) / 2;
+	// Secondary handles: in, out, tilt.
+	const HandleInfo info = _secondary_handles_info[p_id];
+	const int idx = info.point_idx;
+	switch (info.type) {
+		case HandleType::HANDLE_TYPE_OUT: {
+			if (p_cancel) {
+				c->set_point_out(idx, p_restore);
 
-	if (_is_in_handle(p_id, c->get_point_count())) {
-		if (p_cancel) {
-			c->set_point_in(p_id, p_restore);
-			return;
-		}
+				return;
+			}
 
-		ur->create_action(TTR("Set Curve In Position"));
-		ur->add_do_method(c.ptr(), "set_point_in", idx, c->get_point_in(idx));
-		ur->add_undo_method(c.ptr(), "set_point_in", idx, p_restore);
+			ur->create_action(TTR("Set Curve Out Position"));
+			ur->add_do_method(c.ptr(), "set_point_out", idx, c->get_point_out(idx));
+			ur->add_undo_method(c.ptr(), "set_point_out", idx, p_restore);
 
-		if (Path3DEditorPlugin::singleton->mirror_angle_enabled()) {
-			ur->add_do_method(c.ptr(), "set_point_out", idx, Path3DEditorPlugin::singleton->mirror_length_enabled() ? -c->get_point_in(idx) : (-c->get_point_in(idx).normalized() * orig_out_length));
-			ur->add_undo_method(c.ptr(), "set_point_out", idx, Path3DEditorPlugin::singleton->mirror_length_enabled() ? -static_cast<Vector3>(p_restore) : (-static_cast<Vector3>(p_restore).normalized() * orig_out_length));
+			if (Path3DEditorPlugin::singleton->mirror_angle_enabled()) {
+				ur->add_do_method(c.ptr(), "set_point_in", idx, Path3DEditorPlugin::singleton->mirror_length_enabled() ? -c->get_point_out(idx) : (-c->get_point_out(idx).normalized() * orig_in_length));
+				ur->add_undo_method(c.ptr(), "set_point_in", idx, Path3DEditorPlugin::singleton->mirror_length_enabled() ? -static_cast<Vector3>(p_restore) : (-static_cast<Vector3>(p_restore).normalized() * orig_in_length));
+			}
+			ur->commit_action();
+			break;
 		}
-		ur->commit_action();
+		case HandleType::HANDLE_TYPE_IN: {
+			if (p_cancel) {
+				c->set_point_in(idx, p_restore);
+				return;
+			}
 
-	} else {
-		if (p_cancel) {
-			c->set_point_out(idx, p_restore);
+			ur->create_action(TTR("Set Curve In Position"));
+			ur->add_do_method(c.ptr(), "set_point_in", idx, c->get_point_in(idx));
+			ur->add_undo_method(c.ptr(), "set_point_in", idx, p_restore);
 
-			return;
+			if (Path3DEditorPlugin::singleton->mirror_angle_enabled()) {
+				ur->add_do_method(c.ptr(), "set_point_out", idx, Path3DEditorPlugin::singleton->mirror_length_enabled() ? -c->get_point_in(idx) : (-c->get_point_in(idx).normalized() * orig_out_length));
+				ur->add_undo_method(c.ptr(), "set_point_out", idx, Path3DEditorPlugin::singleton->mirror_length_enabled() ? -static_cast<Vector3>(p_restore) : (-static_cast<Vector3>(p_restore).normalized() * orig_out_length));
+			}
+			ur->commit_action();
+			break;
 		}
-
-		ur->create_action(TTR("Set Curve Out Position"));
-		ur->add_do_method(c.ptr(), "set_point_out", idx, c->get_point_out(idx));
-		ur->add_undo_method(c.ptr(), "set_point_out", idx, p_restore);
-
-		if (Path3DEditorPlugin::singleton->mirror_angle_enabled()) {
-			ur->add_do_method(c.ptr(), "set_point_in", idx, Path3DEditorPlugin::singleton->mirror_length_enabled() ? -c->get_point_out(idx) : (-c->get_point_out(idx).normalized() * orig_in_length));
-			ur->add_undo_method(c.ptr(), "set_point_in", idx, Path3DEditorPlugin::singleton->mirror_length_enabled() ? -static_cast<Vector3>(p_restore) : (-static_cast<Vector3>(p_restore).normalized() * orig_in_length));
+		case HandleType::HANDLE_TYPE_TILT: {
+			if (p_cancel) {
+				c->set_point_tilt(idx, p_restore);
+				return;
+			}
+			ur->create_action(TTR("Set Curve Point Tilt"));
+			ur->add_do_method(c.ptr(), "set_point_tilt", idx, c->get_point_tilt(idx));
+			ur->add_undo_method(c.ptr(), "set_point_tilt", idx, p_restore);
+			ur->commit_action();
+			break;
 		}
-		ur->commit_action();
 	}
 }
 
@@ -260,60 +301,126 @@ void Path3DGizmo::redraw() {
 		}
 
 		const Transform3D *r = frames.ptr();
-		Vector<Vector3> v3p;
-		for (int i = 0; i < sample_count - 1; i++) {
+		Vector<Vector3> _collision_segments;
+		Vector<Vector3> bones;
+		Vector<Vector3> ribbon;
+		for (int i = 0; i < sample_count; i++) {
 			const Vector3 p1 = r[i].origin;
-			const Vector3 p2 = r[i + 1].origin;
 			const Vector3 side = r[i].basis.get_column(0);
 			const Vector3 up = r[i].basis.get_column(1);
 			const Vector3 forward = r[i].basis.get_column(2);
 
-			// Curve segment.
-			v3p.push_back(p1);
-			v3p.push_back(p2);
+			// Collision segments.
+			if (i != sample_count) {
+				const Vector3 p2 = r[i + 1].origin;
+				_collision_segments.push_back(p1);
+				_collision_segments.push_back(p2);
+			}
+
+			// Path3D as a ribbon.
+			ribbon.push_back(p1);
 
 			// Fish Bone.
-			v3p.push_back(p1);
-			v3p.push_back(p1 + (side + forward + up * 0.3) * 0.06);
+			const Vector3 p_left = p1 + (side + forward - up * 0.3) * 0.06;
+			const Vector3 p_right = p1 + (-side + forward - up * 0.3) * 0.06;
+			bones.push_back(p1);
+			bones.push_back(p_left);
 
-			v3p.push_back(p1);
-			v3p.push_back(p1 + (-side + forward + up * 0.3) * 0.06);
+			bones.push_back(p1);
+			bones.push_back(p_right);
 		}
 
-		add_lines(v3p, path_material);
-		add_collision_segments(v3p);
+		add_collision_segments(_collision_segments);
+		add_lines(bones, path_material);
+		add_vertices(ribbon, path_material, Mesh::PRIMITIVE_LINE_STRIP);
 	}
 
-	// 2. Draw handles.
+	// 2. Draw handles when selected.
 	if (Path3DEditorPlugin::singleton->get_edited_path() == path) {
-		Vector<Vector3> v3p;
-		Vector<Vector3> handle_points;
-		Vector<Vector3> sec_handle_points;
-
-		for (int i = 0; i < c->get_point_count(); i++) {
-			Vector3 p = c->get_point_position(i);
-			handle_points.push_back(p);
-			// Push out points first so they get selected if the In and Out points are on top of each other.
-			if (i < c->get_point_count() - 1) {
-				v3p.push_back(p);
-				v3p.push_back(p + c->get_point_out(i));
-				sec_handle_points.push_back(p + c->get_point_out(i));
+		PackedVector3Array handle_lines;
+		PackedVector3Array primary_handle_points;
+		PackedVector3Array secondary_handle_points;
+		PackedInt32Array collected_secondary_handle_ids; // Avoid shadowing member on Node3DEditorGizmo.
+
+		_secondary_handles_info.resize(c->get_point_count() * 3);
+
+		for (int idx = 0; idx < c->get_point_count(); idx++) {
+			// Collect primary-handles.
+			const Vector3 pos = c->get_point_position(idx);
+			primary_handle_points.append(pos);
+
+			HandleInfo info;
+			info.point_idx = idx;
+
+			// Collect in-handles except for the first point.
+			if (idx > 0) {
+				info.type = HandleType::HANDLE_TYPE_IN;
+				const int handle_idx = idx * 3 + 0;
+				collected_secondary_handle_ids.append(handle_idx);
+				_secondary_handles_info.write[handle_idx] = info;
+
+				const Vector3 in = c->get_point_in(idx);
+				secondary_handle_points.append(pos + in);
+				handle_lines.append(pos);
+				handle_lines.append(pos + in);
+			}
+
+			// Collect out-handles except for the last point.
+			if (idx < c->get_point_count()) {
+				info.type = HandleType::HANDLE_TYPE_OUT;
+				const int handle_idx = idx * 3 + 1;
+				collected_secondary_handle_ids.append(handle_idx);
+				_secondary_handles_info.write[handle_idx] = info;
+
+				const Vector3 out = c->get_point_out(idx);
+				secondary_handle_points.append(pos + out);
+				handle_lines.append(pos);
+				handle_lines.append(pos + out);
 			}
-			if (i > 0) {
-				v3p.push_back(p);
-				v3p.push_back(p + c->get_point_in(i));
-				sec_handle_points.push_back(p + c->get_point_in(i));
+
+			// Collect tilt-handles.
+			{
+				{
+					info.type = HandleType::HANDLE_TYPE_TILT;
+					const int handle_idx = idx * 3 + 2;
+					collected_secondary_handle_ids.append(handle_idx);
+					_secondary_handles_info.write[handle_idx] = info;
+
+					const Basis posture = c->get_point_baked_posture(idx, true);
+					const Vector3 up = posture.get_column(1);
+					secondary_handle_points.append(pos + up);
+					handle_lines.append(pos);
+					handle_lines.append(pos + up);
+				}
+
+				// Tilt disk.
+				{
+					const Basis posture = c->get_point_baked_posture(idx, false);
+					const Vector3 up = posture.get_column(1);
+					const Vector3 side = posture.get_column(0);
+
+					PackedVector3Array disk;
+					disk.append(pos);
+
+					const int n = 24;
+					for (int i = 0; i <= n; i++) {
+						const float a = Math_TAU * i / n;
+						const Vector3 edge = sin(a) * side + cos(a) * up;
+						disk.append(pos + edge);
+					}
+					add_vertices(disk, path_material, Mesh::PRIMITIVE_LINE_STRIP);
+				}
 			}
 		}
 
-		if (v3p.size() > 1) {
-			add_lines(v3p, path_thin_material);
+		if (handle_lines.size() > 1) {
+			add_lines(handle_lines, path_thin_material);
 		}
-		if (handle_points.size()) {
-			add_handles(handle_points, handles_material);
+		if (primary_handle_points.size()) {
+			add_handles(primary_handle_points, handles_material);
 		}
-		if (sec_handle_points.size()) {
-			add_handles(sec_handle_points, sec_handles_material, Vector<int>(), false, true);
+		if (secondary_handle_points.size()) {
+			add_handles(secondary_handle_points, sec_handles_material, collected_secondary_handle_ids, false, true);
 		}
 	}
 }
@@ -447,6 +554,7 @@ EditorPlugin::AfterGUIInput Path3DEditorPlugin::forward_3d_gui_input(Camera3D *p
 				real_t dist_to_p = p_camera->unproject_position(gt.xform(c->get_point_position(i))).distance_to(mbpos);
 				real_t dist_to_p_out = p_camera->unproject_position(gt.xform(c->get_point_position(i) + c->get_point_out(i))).distance_to(mbpos);
 				real_t dist_to_p_in = p_camera->unproject_position(gt.xform(c->get_point_position(i) + c->get_point_in(i))).distance_to(mbpos);
+				real_t dist_to_p_up = p_camera->unproject_position(gt.xform(c->get_point_position(i) + c->get_point_baked_posture(i, true).get_column(1))).distance_to(mbpos);
 
 				// Find the offset and point index of the place to break up.
 				// Also check for the control points.
@@ -459,18 +567,25 @@ EditorPlugin::AfterGUIInput Path3DEditorPlugin::forward_3d_gui_input(Camera3D *p
 					return EditorPlugin::AFTER_GUI_INPUT_STOP;
 				} else if (dist_to_p_out < click_dist) {
 					EditorUndoRedoManager *ur = EditorUndoRedoManager::get_singleton();
-					ur->create_action(TTR("Remove Out-Control Point"));
+					ur->create_action(TTR("Reset Out-Control Point"));
 					ur->add_do_method(c.ptr(), "set_point_out", i, Vector3());
 					ur->add_undo_method(c.ptr(), "set_point_out", i, c->get_point_out(i));
 					ur->commit_action();
 					return EditorPlugin::AFTER_GUI_INPUT_STOP;
 				} else if (dist_to_p_in < click_dist) {
 					EditorUndoRedoManager *ur = EditorUndoRedoManager::get_singleton();
-					ur->create_action(TTR("Remove In-Control Point"));
+					ur->create_action(TTR("Reset In-Control Point"));
 					ur->add_do_method(c.ptr(), "set_point_in", i, Vector3());
 					ur->add_undo_method(c.ptr(), "set_point_in", i, c->get_point_in(i));
 					ur->commit_action();
 					return EditorPlugin::AFTER_GUI_INPUT_STOP;
+				} else if (dist_to_p_up < click_dist) {
+					EditorUndoRedoManager *ur = EditorUndoRedoManager::get_singleton();
+					ur->create_action(TTR("Reset Point Tilt"));
+					ur->add_do_method(c.ptr(), "set_point_tilt", i, 0.0f);
+					ur->add_undo_method(c.ptr(), "set_point_tilt", i, c->get_point_tilt(i));
+					ur->commit_action();
+					return EditorPlugin::AFTER_GUI_INPUT_STOP;
 				}
 			}
 		}
@@ -497,6 +612,8 @@ void Path3DEditorPlugin::edit(Object *p_object) {
 			pre->get_curve()->emit_signal(SNAME("changed"));
 		}
 	}
+
+	update_overlays();
 	//collision_polygon_editor->edit(Object::cast_to<Node>(p_object));
 }
 

editor/plugins/path_3d_editor_plugin.h

@@ -42,11 +42,26 @@ class MenuButton;
 class Path3DGizmo : public EditorNode3DGizmo {
 	GDCLASS(Path3DGizmo, EditorNode3DGizmo);
 
+	// Map handle id to control point id and handle type.
+	enum HandleType {
+		HANDLE_TYPE_IN,
+		HANDLE_TYPE_OUT,
+		HANDLE_TYPE_TILT,
+	};
+
+	struct HandleInfo {
+		int point_idx; // Index of control point.
+		HandleType type; // Type of this handle.
+	};
+
 	Path3D *path = nullptr;
 	mutable Vector3 original;
 	mutable float orig_in_length;
 	mutable float orig_out_length;
 
+	// Cache information of secondary handles.
+	Vector<HandleInfo> _secondary_handles_info;
+
 public:
 	virtual String get_handle_name(int p_id, bool p_secondary) const override;
 	virtual Variant get_handle_value(int p_id, bool p_secondary) const override;

scene/resources/curve.cpp

@@ -1551,6 +1551,9 @@ void Curve3D::_bake() const {
 	baked_cache_dirty = false;
 
 	if (points.size() == 0) {
+#ifdef TOOLS_ENABLED
+		points_in_cache.clear();
+#endif
 		baked_point_cache.clear();
 		baked_tilt_cache.clear();
 		baked_dist_cache.clear();
@@ -1561,6 +1564,11 @@ void Curve3D::_bake() const {
 	}
 
 	if (points.size() == 1) {
+#ifdef TOOLS_ENABLED
+		points_in_cache.resize(1);
+		points_in_cache.set(0, 0);
+#endif
+
 		baked_point_cache.resize(1);
 		baked_point_cache.set(0, points[0].position);
 		baked_tilt_cache.resize(1);
@@ -1584,10 +1592,18 @@ void Curve3D::_bake() const {
 	{
 		Vector<RBMap<real_t, Vector3>> midpoints = _tessellate_even_length(10, bake_interval);
 
+#ifdef TOOLS_ENABLED
+		points_in_cache.resize(points.size());
+		points_in_cache.set(0, 0);
+#endif
+
 		int pc = 1;
 		for (int i = 0; i < points.size() - 1; i++) {
 			pc++;
 			pc += midpoints[i].size();
+#ifdef TOOLS_ENABLED
+			points_in_cache.set(i + 1, pc - 1);
+#endif
 		}
 
 		baked_point_cache.resize(pc);
@@ -1791,6 +1807,22 @@ real_t Curve3D::_sample_baked_tilt(Interval p_interval) const {
 	return Math::lerp(r[idx], r[idx + 1], frac);
 }
 
+// Internal method for getting posture at a baked point. Assuming caller
+// make all sanity checks.
+Basis Curve3D::_compose_posture(int p_index) const {
+	Vector3 forward = baked_forward_vector_cache[p_index];
+
+	Vector3 up;
+	if (up_vector_enabled) {
+		up = baked_up_vector_cache[p_index];
+	} else {
+		up = Vector3(0.0, 1.0, 0.0);
+	}
+
+	const Basis frame = Basis::looking_at(forward, up);
+	return frame;
+}
+
 Basis Curve3D::_sample_posture(Interval p_interval, bool p_apply_tilt) const {
 	// Assuming that p_interval is valid.
 	ERR_FAIL_INDEX_V_MSG(p_interval.idx, baked_point_cache.size(), Basis(), "Invalid interval");
@@ -1801,35 +1833,48 @@ Basis Curve3D::_sample_posture(Interval p_interval, bool p_apply_tilt) const {
 	int idx = p_interval.idx;
 	real_t frac = p_interval.frac;
 
-	Vector3 forward_begin = baked_forward_vector_cache[idx];
-	Vector3 forward_end = baked_forward_vector_cache[idx + 1];
+	// Get frames at both ends of the interval, then interpolate.
+	const Basis frame_begin = _compose_posture(idx);
+	const Basis frame_end = _compose_posture(idx + 1);
+	const Basis frame = frame_begin.slerp(frame_end, frac).orthonormalized();
 
-	Vector3 up_begin;
-	Vector3 up_end;
-	if (up_vector_enabled) {
-		up_begin = baked_up_vector_cache[idx];
-		up_end = baked_up_vector_cache[idx + 1];
-	} else {
-		up_begin = Vector3(0.0, 1.0, 0.0);
-		up_end = Vector3(0.0, 1.0, 0.0);
+	if (!p_apply_tilt) {
+		return frame;
 	}
 
-	// Build frames at both ends of the interval, then interpolate.
-	const Basis frame_begin = Basis::looking_at(forward_begin, up_begin);
-	const Basis frame_end = Basis::looking_at(forward_end, up_end);
-	const Basis frame = frame_begin.slerp(frame_end, frac).orthonormalized();
+	// Applying tilt.
+	const real_t tilt = _sample_baked_tilt(p_interval);
+	Vector3 tangent = -frame.get_column(2);
+
+	const Basis twist(tangent, tilt);
+	return twist * frame;
+}
+
+#ifdef TOOLS_ENABLED
+// Get posture at a control point. Needed for Gizmo implementation.
+Basis Curve3D::get_point_baked_posture(int p_index, bool p_apply_tilt) const {
+	if (baked_cache_dirty) {
+		_bake();
+	}
+
+	// Assuming that p_idx is valid.
+	ERR_FAIL_INDEX_V_MSG(p_index, points_in_cache.size(), Basis(), "Invalid control point index");
+
+	int baked_idx = points_in_cache[p_index];
+	Basis frame = _compose_posture(baked_idx);
 
 	if (!p_apply_tilt) {
 		return frame;
 	}
 
 	// Applying tilt.
-	const real_t tilt = _sample_baked_tilt(p_interval);
-	Vector3 forward = frame.get_column(2);
+	const real_t tilt = points[p_index].tilt;
+	Vector3 tangent = -frame.get_column(2);
+	const Basis twist(tangent, tilt);
 
-	const Basis twist(forward, tilt);
 	return twist * frame;
 }
+#endif
 
 Vector3 Curve3D::sample_baked(real_t p_offset, bool p_cubic) const {
 	if (baked_cache_dirty) {

scene/resources/curve.h

@@ -258,6 +258,10 @@ class Curve3D : public Resource {
 	};
 
 	Vector<Point> points;
+#ifdef TOOLS_ENABLED
+	// For Path3DGizmo.
+	mutable Vector<size_t> points_in_cache;
+#endif
 
 	mutable bool baked_cache_dirty = false;
 	mutable PackedVector3Array baked_point_cache;
@@ -280,6 +284,7 @@ class Curve3D : public Resource {
 	Vector3 _sample_baked(Interval p_interval, bool p_cubic) const;
 	real_t _sample_baked_tilt(Interval p_interval) const;
 	Basis _sample_posture(Interval p_interval, bool p_apply_tilt = false) const;
+	Basis _compose_posture(int p_index) const;
 
 	real_t bake_interval = 0.2;
 	bool up_vector_enabled = true;
@@ -302,6 +307,11 @@ protected:
 	static void _bind_methods();
 
 public:
+#ifdef TOOLS_ENABLED
+	// For Path3DGizmo.
+	Basis get_point_baked_posture(int p_index, bool p_apply_tilt = false) const;
+#endif
+
 	int get_point_count() const;
 	void set_point_count(int p_count);
 	void add_point(const Vector3 &p_position, const Vector3 &p_in = Vector3(), const Vector3 &p_out = Vector3(), int p_atpos = -1);