Add Deterministic option to IterateIK3D

doc/classes/BoneExpander3D.xml

@@ -0,0 +1,71 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<class name="BoneExpander3D" inherits="SkeletonModifier3D" experimental="This SkeletonModifier3D interferes with the Skin in a slightly unsafe way. Performance and stability have not been sufficiently optimized." xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../class.xsd">
+	<brief_description>
+		Scales the visual appearance of the specified bone without causing shear in the children.
+	</brief_description>
+	<description>
+		Scales only the visual appearance without changing the bone pose scale. This is achieved by modifying the bone pose position and skin bindings instead of the bone pose scale. In other words, the only thing other modifiers can obtain from this modifier via the bone is the bone pose position.
+		If you use [BoneExpander3D] with [IKModifier3D] or [SpringBoneSimulator3D], you should enable [member IKModifier3D.mutable_bone_axes] and [member SpringBoneSimulator3D.mutable_bone_axes].
+		[b]Note:[/b] Changing the skin is not a role of the [SkeletonModifier3D] originally, so combining it with [RetargetModifier3D] or baking IK animation to FK animation may result in unintended behaviors.
+	</description>
+	<tutorials>
+	</tutorials>
+	<methods>
+		<method name="clear_setting">
+			<return type="void" />
+			<description>
+				Clears all settings.
+			</description>
+		</method>
+		<method name="get_bone" qualifiers="const">
+			<return type="int" />
+			<param index="0" name="index" type="int" />
+			<description>
+				Returns the scaled bone of the setting at [param index].
+			</description>
+		</method>
+		<method name="get_bone_name" qualifiers="const">
+			<return type="StringName" />
+			<param index="0" name="index" type="int" />
+			<description>
+				Returns the scaled bone name of the setting at [param index].
+			</description>
+		</method>
+		<method name="get_bone_scale" qualifiers="const">
+			<return type="Vector3" />
+			<param index="0" name="index" type="int" />
+			<description>
+				Returns the scale of the setting at [param index].
+			</description>
+		</method>
+		<method name="set_bone">
+			<return type="void" />
+			<param index="0" name="index" type="int" />
+			<param index="1" name="bone" type="int" />
+			<description>
+				Sets the scaled bone of the setting at [param index].
+			</description>
+		</method>
+		<method name="set_bone_name">
+			<return type="void" />
+			<param index="0" name="index" type="int" />
+			<param index="1" name="bone_name" type="StringName" />
+			<description>
+				Sets the scaled bone name of the setting at [param index].
+			</description>
+		</method>
+		<method name="set_bone_scale">
+			<return type="void" />
+			<param index="0" name="index" type="int" />
+			<param index="1" name="scale" type="Vector3" />
+			<description>
+				[b]Note:[/b] The [param scale] value is recommended to be non-zero.
+			</description>
+		</method>
+	</methods>
+	<members>
+		<member name="setting_size" type="int" setter="set_setting_size" getter="get_setting_size" default="0">
+			The number of setting in the modifier.
+		</member>
+	</members>
+</class>

doc/classes/IKModifier3D.xml

@@ -5,7 +5,6 @@
 	</brief_description>
 	<description>
 		Base class of [SkeletonModifier3D]s that has some joint lists and applies inverse kinematics. This class has some structs, enums, and helper methods which are useful to solve inverse kinematics.
-		[b]Note:[/b] The IK classes that extend this handle rotation only, with bone lengths cached. It means that a position movement between processed chains can cause unintended movement.
 	</description>
 	<tutorials>
 	</tutorials>
@@ -36,4 +35,10 @@
 			</description>
 		</method>
 	</methods>
+	<members>
+		<member name="mutable_bone_axes" type="bool" setter="set_mutable_bone_axes" getter="are_bone_axes_mutable" default="true">
+			If [code]true[/code], the solver retrieves the bone axis from the bone pose every frame.
+			If [code]false[/code], the solver retrieves the bone axis from the bone rest and caches it, which increases performance slightly, but position changes in the bone pose before processing this [IKModifier3D] are ignored.
+		</member>
+	</members>
 </class>

doc/classes/IterateIK3D.xml

@@ -145,6 +145,10 @@
 			The maximum amount each bone can rotate in a single iteration.
 			[b]Note:[/b] This limitation is applied during each iteration. For example, if [member max_iterations] is [code]4[/code] and [member angular_delta_limit] is [code]5[/code] degrees, the maximum rotation possible in a single frame is [code]20[/code] degrees.
 		</member>
+		<member name="deterministic" type="bool" setter="set_deterministic" getter="is_deterministic" default="false">
+			If [code]false[/code], the result is calculated from the previous frame's [IterateIK3D] result as the initial state.
+			If [code]true[/code], the previous frame's [IterateIK3D] result is discarded. At this point, the new result is calculated from the bone pose excluding the [IterateIK3D] as the initial state. This means the result will be always equal as long as the target position and the previous bone pose are the same. However, if [member angular_delta_limit] and [member max_iterations] are set too small, the end bone of the chain will never reach the target.
+		</member>
 		<member name="max_iterations" type="int" setter="set_max_iterations" getter="get_max_iterations" default="4">
 			The number of iteration loops used by the IK solver to produce more accurate results.
 		</member>

doc/classes/Skeleton3D.xml

@@ -412,12 +412,22 @@
 				Emitted when the value of [member show_rest_only] changes.
 			</description>
 		</signal>
+		<signal name="skeleton_rendered">
+			<description>
+				Emitted when the skins are rendered and modified poses are restored in the update process.
+			</description>
+		</signal>
 		<signal name="skeleton_updated">
 			<description>
 				Emitted when the final pose has been calculated will be applied to the skin in the update process.
 				This means that all [SkeletonModifier3D] processing is complete. In order to detect the completion of the processing of each [SkeletonModifier3D], use [signal SkeletonModifier3D.modification_processed].
 			</description>
 		</signal>
+		<signal name="skin_changed">
+			<description>
+				Emitted when the new skin is bound or bound skins are changed.
+			</description>
+		</signal>
 	</signals>
 	<constants>
 		<constant name="NOTIFICATION_UPDATE_SKELETON" value="50">

doc/classes/SpringBoneSimulator3D.xml

@@ -637,6 +637,10 @@
 			The constant force that always affected bones. It is equal to the result when the parent [Skeleton3D] moves at this speed in the opposite direction.
 			This is useful for effects such as wind and anti-gravity.
 		</member>
+		<member name="mutable_bone_axes" type="bool" setter="set_mutable_bone_axes" getter="are_bone_axes_mutable" default="true">
+			If [code]true[/code], the solver retrieves the bone axis from the bone pose every frame.
+			If [code]false[/code], the solver retrieves the bone axis from the bone rest and caches it, which increases performance slightly, but position changes in the bone pose before processing this [SpringBoneSimulator3D] are ignored.
+		</member>
 		<member name="setting_count" type="int" setter="set_setting_count" getter="get_setting_count" default="0">
 			The number of settings.
 		</member>

editor/scene/3d/gizmos/chain_ik_3d_gizmo_plugin.cpp

@@ -135,13 +135,18 @@ Ref<ArrayMesh> ChainIK3DGizmoPlugin::get_joints_mesh(Skeleton3D *p_skeleton, Cha
 		int current_bone = -1;
 		int prev_bone = -1;
 		int joint_end = p_ik->get_joint_count(i) - 1;
+		float prev_length = INFINITY;
 		bool is_extended = p_ik->is_end_bone_extended(i) && p_ik->get_end_bone_length(i) > 0;
+		Transform3D anc_global_pose = p_ik->get_chain_root_global_rest(i);
 		for (int j = 0; j <= joint_end; j++) {
 			current_bone = p_ik->get_joint_bone(i, j);
-			Transform3D global_pose = p_skeleton->get_bone_global_rest(current_bone);
 			if (j > 0) {
+				int prev_joint = j - 1;
 				Transform3D parent_global_pose = p_skeleton->get_bone_global_rest(prev_bone);
-				draw_line(surface_tool, parent_global_pose.origin, global_pose.origin, bone_color);
+				Vector3 bone_vector = p_ik->get_bone_vector(i, prev_joint);
+				float current_length = bone_vector.length();
+				Vector3 center = parent_global_pose.translated_local(bone_vector).origin;
+				draw_line(surface_tool, parent_global_pose.origin, center, bone_color);
 
 				if (it_ik) {
 					// Draw rotation axis vector if not ROTATION_AXIS_ALL.
@@ -150,15 +155,14 @@ Ref<ArrayMesh> ChainIK3DGizmoPlugin::get_joints_mesh(Skeleton3D *p_skeleton, Cha
 						if (rotation_axis != SkeletonModifier3D::ROTATION_AXIS_ALL) {
 							Vector3 axis_vector = it_ik->get_joint_rotation_axis_vector(i, j);
 							if (!axis_vector.is_zero_approx()) {
-								float rot_axis_length = (global_pose.origin - parent_global_pose.origin).length() * 0.2; // Use 20% of the bone length for the rotation axis vector.
-								Vector3 axis = global_pose.basis.xform(axis_vector.normalized()) * rot_axis_length;
-								draw_line(surface_tool, global_pose.origin - axis, global_pose.origin + axis, bone_color);
+								float rot_axis_length = bone_vector.length() * 0.2; // Use 20% of the bone length for the rotation axis vector.
+								Vector3 axis = parent_global_pose.basis.xform(axis_vector.normalized()) * rot_axis_length;
+								draw_line(surface_tool, center - axis, center + axis, bone_color);
 							}
 						}
 					}
 
 					// Draw parent limitation shape.
-					int prev_joint = j - 1;
 					Ref<JointLimitation3D> lim = it_ik->get_joint_limitation(i, prev_joint);
 					if (lim.is_valid()) {
 						// Limitation space should bind parent bone rest.
@@ -170,28 +174,36 @@ Ref<ArrayMesh> ChainIK3DGizmoPlugin::get_joints_mesh(Skeleton3D *p_skeleton, Cha
 								surface_tool->set_weights(weights);
 							}
 						}
-						Transform3D tr = parent_global_pose;
-						Vector3 forward = p_skeleton->get_bone_rest(current_bone).origin;
-						tr.basis *= it_ik->get_joint_limitation_space(i, prev_joint, forward);
-						lim->draw_shape(surface_tool, tr, forward.length(), bone_color);
-						Vector3 x_axis = tr.basis.get_column(Vector3::AXIS_X).normalized() * forward.length() * 0.1;
-						Vector3 z_axis = tr.basis.get_column(Vector3::AXIS_Z).normalized() * forward.length() * 0.1;
+						Transform3D tr = anc_global_pose;
+						tr.basis *= it_ik->get_joint_limitation_space(i, prev_joint, bone_vector.normalized());
+						float sl = MIN(current_length, prev_length);
+						lim->draw_shape(surface_tool, tr, sl, bone_color);
+						sl *= 0.1;
+						Vector3 x_axis = tr.basis.get_column(Vector3::AXIS_X).normalized() * sl;
+						Vector3 z_axis = tr.basis.get_column(Vector3::AXIS_Z).normalized() * sl;
 						draw_line(surface_tool, tr.origin + x_axis * 2, tr.origin + x_axis * 3, limitation_x_axis_color); // Offset 20%.
 						draw_line(surface_tool, tr.origin + z_axis * 2, tr.origin + z_axis * 3, limitation_z_axis_color); // Offset 20%.
 					}
 				}
+				prev_length = current_length;
+				Transform3D tr = p_skeleton->get_bone_rest(current_bone);
+				tr.origin = bone_vector;
+				parent_global_pose *= tr;
+				anc_global_pose = parent_global_pose;
 			}
 			if (j == joint_end && is_extended) {
-				Vector3 axis = p_ik->get_bone_axis(current_bone, p_ik->get_end_bone_direction(i));
-				if (axis.is_zero_approx()) {
+				Transform3D current_global_pose = p_skeleton->get_bone_global_rest(current_bone);
+				Vector3 bone_vector = p_ik->get_bone_vector(i, j);
+				if (bone_vector.is_zero_approx()) {
 					continue;
 				}
+				float current_length = bone_vector.length();
 				bones.write[0] = current_bone;
 				surface_tool->set_bones(bones);
 				surface_tool->set_weights(weights);
-				float length = p_ik->get_end_bone_length(i);
-				axis = global_pose.xform(axis * length);
-				draw_line(surface_tool, global_pose.origin, axis, bone_color);
+				Vector3 center = current_global_pose.translated_local(bone_vector).origin;
+				draw_line(surface_tool, current_global_pose.origin, center, bone_color);
+
 				if (it_ik) {
 					// Draw limitation shape.
 					Ref<JointLimitation3D> lim = it_ik->get_joint_limitation(i, j);
@@ -205,12 +217,13 @@ Ref<ArrayMesh> ChainIK3DGizmoPlugin::get_joints_mesh(Skeleton3D *p_skeleton, Cha
 								surface_tool->set_weights(weights);
 							}
 						}
-						Vector3 forward = it_ik->get_bone_axis(current_bone, it_ik->get_end_bone_direction(i));
-						Transform3D tr = global_pose;
-						tr.basis *= it_ik->get_joint_limitation_space(i, j, forward);
-						lim->draw_shape(surface_tool, tr, length, bone_color);
-						Vector3 x_axis = tr.basis.get_column(Vector3::AXIS_X).normalized() * length * 0.1;
-						Vector3 z_axis = tr.basis.get_column(Vector3::AXIS_Z).normalized() * length * 0.1;
+						Transform3D tr = anc_global_pose;
+						tr.basis *= it_ik->get_joint_limitation_space(i, j, bone_vector.normalized());
+						float sl = MIN(current_length, prev_length);
+						lim->draw_shape(surface_tool, tr, sl, bone_color);
+						sl *= 0.1;
+						Vector3 x_axis = tr.basis.get_column(Vector3::AXIS_X).normalized() * sl;
+						Vector3 z_axis = tr.basis.get_column(Vector3::AXIS_Z).normalized() * sl;
 						draw_line(surface_tool, tr.origin + x_axis * 2, tr.origin + x_axis * 3, limitation_x_axis_color); // Offset 20%.
 						draw_line(surface_tool, tr.origin + z_axis * 2, tr.origin + z_axis * 3, limitation_z_axis_color); // Offset 20%.
 					}
@@ -231,10 +244,10 @@ Ref<ArrayMesh> ChainIK3DGizmoPlugin::get_joints_mesh(Skeleton3D *p_skeleton, Cha
 						if (rotation_axis != SkeletonModifier3D::ROTATION_AXIS_ALL) {
 							Vector3 axis_vector = it_ik->get_joint_rotation_axis_vector(i, j);
 							if (!axis_vector.is_zero_approx()) {
-								Transform3D next_bone_global_pose = p_skeleton->get_bone_global_rest(it_ik->get_joint_bone(i, 1));
-								float rot_axis_length = (next_bone_global_pose.origin - global_pose.origin).length() * 0.2; // Use 20% of the bone length for the rotation axis vector.
-								Vector3 axis = global_pose.basis.xform(axis_vector.normalized()) * rot_axis_length;
-								draw_line(surface_tool, global_pose.origin - axis, global_pose.origin + axis, bone_color);
+								Vector3 bone_vector = p_ik->get_bone_vector(i, j);
+								float rot_axis_length = bone_vector.length() * 0.2; // Use 20% of the bone length for the rotation axis vector.
+								Vector3 axis = anc_global_pose.basis.xform(axis_vector.normalized()) * rot_axis_length;
+								draw_line(surface_tool, anc_global_pose.origin - axis, anc_global_pose.origin + axis, bone_color);
 							}
 						}
 					}

editor/scene/3d/gizmos/spring_bone_3d_gizmo_plugin.cpp

@@ -142,8 +142,10 @@ Ref<ArrayMesh> SpringBoneSimulator3DGizmoPlugin::get_joints_mesh(Skeleton3D *p_s
 			Transform3D global_pose = p_skeleton->get_bone_global_rest(current_bone);
 			if (j > 0) {
 				Transform3D parent_global_pose = p_skeleton->get_bone_global_rest(prev_bone);
-				draw_line(surface_tool, parent_global_pose.origin, global_pose.origin, bone_color);
-				draw_sphere(surface_tool, global_pose.basis, global_pose.origin, p_simulator->get_joint_radius(i, j - 1), bone_color);
+				Vector3 bone_vector = p_simulator->get_bone_vector(i, j - 1);
+				Vector3 center = parent_global_pose.translated_local(bone_vector).origin;
+				draw_line(surface_tool, parent_global_pose.origin, center, bone_color);
+				draw_sphere(surface_tool, global_pose.basis, center, p_simulator->get_joint_radius(i, j - 1), bone_color);
 
 				// Draw rotation axis vector if not ROTATION_AXIS_ALL.
 				if (j != joint_end || (j == joint_end && is_extended)) {
@@ -153,22 +155,22 @@ Ref<ArrayMesh> SpringBoneSimulator3DGizmoPlugin::get_joints_mesh(Skeleton3D *p_s
 						if (!axis_vector.is_zero_approx()) {
 							float line_length = p_simulator->get_joint_radius(i, j - 1) * 2.0;
 							Vector3 axis = global_pose.basis.xform(axis_vector.normalized()) * line_length;
-							draw_line(surface_tool, global_pose.origin - axis, global_pose.origin + axis, bone_color);
+							draw_line(surface_tool, center - axis, center + axis, bone_color);
 						}
 					}
 				}
 			}
 			if (j == joint_end && is_extended) {
-				Vector3 axis = p_simulator->get_end_bone_axis(current_bone, p_simulator->get_end_bone_direction(i));
-				if (axis.is_zero_approx()) {
+				Vector3 bone_vector = p_simulator->get_bone_vector(i, j);
+				if (bone_vector.is_zero_approx()) {
 					continue;
 				}
 				bones[0] = current_bone;
 				surface_tool->set_bones(Vector<int>(bones));
 				surface_tool->set_weights(Vector<float>(weights));
-				axis = global_pose.xform(axis * p_simulator->get_end_bone_length(i));
-				draw_line(surface_tool, global_pose.origin, axis, bone_color);
-				draw_sphere(surface_tool, global_pose.basis, axis, p_simulator->get_joint_radius(i, j), bone_color);
+				Vector3 center = global_pose.translated_local(bone_vector).origin;
+				draw_line(surface_tool, global_pose.origin, center, bone_color);
+				draw_sphere(surface_tool, global_pose.basis, center, p_simulator->get_joint_radius(i, j), bone_color);
 			} else {
 				bones[0] = current_bone;
 				surface_tool->set_bones(Vector<int>(bones));