rigidbody: Add rigid body constraints

Constraints connect two rigid bodies.
Depending on which constraint is used different degrees of freedom
are limited, e.g. a hinge constraint only allows the objects to rotate
around a common axis.

Constraints are implemented as individual objects and bahave similar to
rigid bodies in terms of adding/removing/validating.

The position and orientation of the constraint object is the pivot point
of the constraint.

Constraints have their own group in the rigid body world.

To make connecting rigid bodies easier, there is a "Connect" operator that
creates an empty objects with a rigid body constraint connecting the selected
objects to active.

Currently the following constraints are implemented:
* Fixed
* Point
* Hinge
* Slider
* Piston
* Generic

Note: constraint limits aren't animatable yet).

1 files changed, 289 insertions, 0 deletions

diff --git a/source/blender/makesrna/intern/rna_rigidbody.c b/source/blender/makesrna/intern/rna_rigidbody.c
index 1e0e250ac66..206c6e19c41 100644
--- a/source/blender/makesrna/intern/rna_rigidbody.c
+++ b/source/blender/makesrna/intern/rna_rigidbody.c
@@ -59,6 +59,16 @@ EnumPropertyItem rigidbody_ob_shape_items[] = {
 	{RB_SHAPE_TRIMESH, "MESH", ICON_MESH_MONKEY, "Mesh", "Mesh consisting of triangles only, allowing for more detailed interactions than convex hulls"},
 	{0, NULL, 0, NULL, NULL}};
 
+/* collision shapes of constraints in rigid body sim */
+EnumPropertyItem rigidbody_con_type_items[] = {
+	{RBC_TYPE_FIXED, "FIXED", ICON_FORCE_FORCE, "Fixed", "Glues rigid bodies together"},
+	{RBC_TYPE_POINT, "POINT", ICON_FORCE_FORCE, "Point", "Constrains rigid bodies to move aound common pivot point"},
+	{RBC_TYPE_HINGE, "HINGE", ICON_FORCE_FORCE, "Hinge", "Restricts rigid body rotation to one axis"},
+	{RBC_TYPE_SLIDER, "SLIDER", ICON_FORCE_FORCE, "Slider", "Restricts rigid boddy translation to one axis"},
+	{RBC_TYPE_PISTON, "PISTON", ICON_FORCE_FORCE, "Piston", "Restricts rigid boddy translation and rotation to one axis"},
+	{RBC_TYPE_6DOF, "GENERIC", ICON_FORCE_FORCE, "Generic", "Restricts translation and rotation to specified axes"},
+	{0, NULL, 0, NULL, NULL}};
+
 
 #ifdef RNA_RUNTIME
 
@@ -286,6 +296,91 @@ static void rna_RigidBodyOb_angular_damping_set(PointerRNA *ptr, float value)
 		RB_body_set_angular_damping(rbo->physics_object, value);
 }
 
+static char *rna_RigidBodyCon_path(PointerRNA *ptr)
+{
+	/* NOTE: this hardcoded path should work as long as only Objects have this */
+	return BLI_sprintfN("rigid_body_constraint");
+}
+
+static void rna_RigidBodyCon_type_set(PointerRNA *ptr, int value)
+{
+	RigidBodyCon *rbc = (RigidBodyCon *)ptr->data;
+
+	rbc->type = value;
+	rbc->flag |= RBC_FLAG_NEEDS_VALIDATE;
+}
+
+static void rna_RigidBodyCon_enabled_set(PointerRNA *ptr, int value)
+{
+	RigidBodyCon *rbc = (RigidBodyCon *)ptr->data;
+
+	RB_FLAG_SET(rbc->flag, value, RBC_FLAG_ENABLED);
+
+	if (rbc->physics_constraint)
+		RB_constraint_set_enabled(rbc->physics_constraint, value);
+}
+
+static void rna_RigidBodyCon_disable_collisions_set(PointerRNA *ptr, int value)
+{
+	RigidBodyCon *rbc = (RigidBodyCon *)ptr->data;
+
+	RB_FLAG_SET(rbc->flag, value, RBC_FLAG_DISABLE_COLLISIONS);
+
+	rbc->flag |= RBC_FLAG_NEEDS_VALIDATE;
+}
+
+static void rna_RigidBodyCon_use_breaking_set(PointerRNA *ptr, int value)
+{
+	RigidBodyCon *rbc = (RigidBodyCon *)ptr->data;
+
+	if (value) {
+		rbc->flag |= RBC_FLAG_USE_BREAKING;
+		if (rbc->physics_constraint)
+			RB_constraint_set_breaking_threshold(rbc->physics_constraint, rbc->breaking_threshold);
+	}
+	else {
+		rbc->flag &= ~RBC_FLAG_USE_BREAKING;
+		if (rbc->physics_constraint)
+			RB_constraint_set_breaking_threshold(rbc->physics_constraint, FLT_MAX);
+	}
+}
+
+static void rna_RigidBodyCon_breaking_threshold_set(PointerRNA *ptr, float value)
+{
+	RigidBodyCon *rbc = (RigidBodyCon *)ptr->data;
+
+	rbc->breaking_threshold = value;
+
+	if (rbc->physics_constraint && (rbc->flag & RBC_FLAG_USE_BREAKING))
+		RB_constraint_set_breaking_threshold(rbc->physics_constraint, value);
+}
+
+static void rna_RigidBodyCon_override_solver_iterations_set(PointerRNA *ptr, int value)
+{
+	RigidBodyCon *rbc = (RigidBodyCon *)ptr->data;
+
+	if (value) {
+		rbc->flag |= RBC_FLAG_OVERRIDE_SOLVER_ITERATIONS;
+		if (rbc->physics_constraint)
+			RB_constraint_set_solver_iterations(rbc->physics_constraint, rbc->num_solver_iterations);
+	}
+	else {
+		rbc->flag &= ~RBC_FLAG_OVERRIDE_SOLVER_ITERATIONS;
+		if (rbc->physics_constraint)
+			RB_constraint_set_solver_iterations(rbc->physics_constraint, -1);
+	}
+}
+
+static void rna_RigidBodyCon_num_solver_iterations_set(PointerRNA *ptr, int value)
+{
+	RigidBodyCon *rbc = (RigidBodyCon *)ptr->data;
+
+	rbc->num_solver_iterations = value;
+
+	if (rbc->physics_constraint && (rbc->flag & RBC_FLAG_OVERRIDE_SOLVER_ITERATIONS))
+		RB_constraint_set_solver_iterations(rbc->physics_constraint, value);
+}
+
 #else
 
 static void rna_def_rigidbody_world(BlenderRNA *brna)
@@ -304,6 +399,12 @@ static void rna_def_rigidbody_world(BlenderRNA *brna)
 	RNA_def_property_flag(prop, PROP_EDITABLE|PROP_ID_SELF_CHECK);
 	RNA_def_property_ui_text(prop, "Group", "Group containing objects participating in this simulation");
 	RNA_def_property_update(prop, NC_SCENE, "rna_RigidBodyWorld_reset");
+
+	prop = RNA_def_property(srna, "constraints", PROP_POINTER, PROP_NONE);
+	RNA_def_property_struct_type(prop, "Group");
+	RNA_def_property_flag(prop, PROP_EDITABLE|PROP_ID_SELF_CHECK);
+	RNA_def_property_ui_text(prop, "Constraints", "Group containing rigid body constraint objects");
+	RNA_def_property_update(prop, NC_SCENE, "rna_RigidBodyWorld_reset");
 	
 	/* booleans */
 	prop = RNA_def_property(srna, "enabled", PROP_BOOLEAN, PROP_NONE);
@@ -501,10 +602,198 @@ static void rna_def_rigidbody_object(BlenderRNA *brna)
 	RNA_def_property_flag(prop, PROP_LIB_EXCEPTION);
 }
 
+static void rna_def_rigidbody_constraint(BlenderRNA *brna)
+{
+	StructRNA *srna;
+	PropertyRNA *prop;
+
+	srna = RNA_def_struct(brna, "RigidBodyConstraint", NULL);
+	RNA_def_struct_sdna(srna, "RigidBodyCon");
+	RNA_def_struct_ui_text(srna, "Rigid Body Constraint", "Constraint influencing Objects inside Rigid Body Simulation");
+	RNA_def_struct_path_func(srna, "rna_RigidBodyCon_path");
+
+	/* Enums */
+	prop = RNA_def_property(srna, "type", PROP_ENUM, PROP_NONE);
+	RNA_def_property_enum_sdna(prop, NULL, "type");
+	RNA_def_property_enum_items(prop, rigidbody_con_type_items);
+	RNA_def_property_enum_funcs(prop, NULL, "rna_RigidBodyCon_type_set", NULL);
+	RNA_def_property_ui_text(prop, "Type", "Type of Rigid Body Constraint");
+	RNA_def_property_clear_flag(prop, PROP_ANIMATABLE);
+	RNA_def_property_update(prop, NC_OBJECT | ND_POINTCACHE, "rna_RigidBodyOb_reset");
+
+	prop = RNA_def_property(srna, "enabled", PROP_BOOLEAN, PROP_NONE);
+	RNA_def_property_boolean_sdna(prop, NULL, "flag", RBC_FLAG_ENABLED);
+	RNA_def_property_boolean_funcs(prop, NULL, "rna_RigidBodyCon_enabled_set");
+	RNA_def_property_ui_text(prop, "Enabled", "Enable this constraint");
+	RNA_def_property_update(prop, NC_OBJECT | ND_POINTCACHE, "rna_RigidBodyOb_reset");
+
+	prop = RNA_def_property(srna, "disable_collisions", PROP_BOOLEAN, PROP_NONE);
+	RNA_def_property_boolean_sdna(prop, NULL, "flag", RBC_FLAG_DISABLE_COLLISIONS);
+	RNA_def_property_boolean_funcs(prop, NULL, "rna_RigidBodyCon_disable_collisions_set");
+	RNA_def_property_ui_text(prop, "Disable Collisions", "Disables collisions between constrained ridid bodies");
+	RNA_def_property_update(prop, NC_OBJECT | ND_POINTCACHE, "rna_RigidBodyOb_reset");
+
+	prop = RNA_def_property(srna, "object1", PROP_POINTER, PROP_NONE);
+	RNA_def_property_pointer_sdna(prop, NULL, "ob1");
+	RNA_def_property_flag(prop, PROP_EDITABLE);
+	RNA_def_property_ui_text(prop, "Object 1", "First Rigid Body Object to be constrained");
+	RNA_def_property_flag(prop, PROP_EDITABLE);
+	RNA_def_property_update(prop, NC_OBJECT | ND_POINTCACHE, "rna_RigidBodyOb_reset");
+
+	prop = RNA_def_property(srna, "object2", PROP_POINTER, PROP_NONE);
+	RNA_def_property_pointer_sdna(prop, NULL, "ob2");
+	RNA_def_property_flag(prop, PROP_EDITABLE);
+	RNA_def_property_ui_text(prop, "Object 2", "Second Rigid Body Object to be constrained");
+	RNA_def_property_flag(prop, PROP_EDITABLE);
+	RNA_def_property_update(prop, NC_OBJECT | ND_POINTCACHE, "rna_RigidBodyOb_reset");
+
+	/* Breaking Threshold */
+	prop = RNA_def_property(srna, "use_breaking", PROP_BOOLEAN, PROP_NONE);
+	RNA_def_property_boolean_sdna(prop, NULL, "flag", RBC_FLAG_USE_BREAKING);
+	RNA_def_property_boolean_funcs(prop, NULL, "rna_RigidBodyCon_use_breaking_set");
+	RNA_def_property_ui_text(prop, "Breakable", "Constraint can be broaken if it receives an impulse above the threshold");
+	RNA_def_property_update(prop, NC_OBJECT | ND_POINTCACHE, "rna_RigidBodyOb_reset");
+
+	prop = RNA_def_property(srna, "breaking_threshold", PROP_FLOAT, PROP_NONE);
+	RNA_def_property_float_sdna(prop, NULL, "breaking_threshold");
+	RNA_def_property_range(prop, 0.0f, FLT_MAX);
+	RNA_def_property_ui_range(prop, 0.0f, 1000.0f, 100.0, 2);
+	RNA_def_property_float_default(prop, 10.0f);
+	RNA_def_property_float_funcs(prop, NULL, "rna_RigidBodyCon_breaking_threshold_set", NULL);
+	RNA_def_property_ui_text(prop, "Breaking Threshold", "Impulse threshold that must be reached for the constraint to break");
+	RNA_def_property_update(prop, NC_OBJECT | ND_POINTCACHE, "rna_RigidBodyOb_reset");
+
+	/* Solver Iterations */
+	prop = RNA_def_property(srna, "override_solver_iterations", PROP_BOOLEAN, PROP_NONE);
+	RNA_def_property_boolean_sdna(prop, NULL, "flag", RBC_FLAG_OVERRIDE_SOLVER_ITERATIONS);
+	RNA_def_property_boolean_funcs(prop, NULL, "rna_RigidBodyCon_override_solver_iterations_set");
+	RNA_def_property_ui_text(prop, "Override Solver Iterations", "Overrides the number of solver iterations for this constraint");
+	RNA_def_property_update(prop, NC_OBJECT | ND_POINTCACHE, "rna_RigidBodyOb_reset");
+
+	prop = RNA_def_property(srna, "num_solver_iterations", PROP_INT, PROP_NONE);
+	RNA_def_property_int_sdna(prop, NULL, "num_solver_iterations");
+	RNA_def_property_range(prop, 1, 1000);
+	RNA_def_property_ui_range(prop, 1, 100, 1, 0);
+	RNA_def_property_int_default(prop, 10);
+	RNA_def_property_int_funcs(prop, NULL, "rna_RigidBodyCon_num_solver_iterations_set", NULL);
+	RNA_def_property_ui_text(prop, "Solver Iterations", "Number of constraint solver iterations made per simulation step (higher values are more accurate but slower)");
+	RNA_def_property_update(prop, NC_OBJECT, "rna_RigidBodyOb_reset");
+
+	/* Limits */
+	prop = RNA_def_property(srna, "use_limit_lin_x", PROP_BOOLEAN, PROP_NONE);
+	RNA_def_property_boolean_sdna(prop, NULL, "flag", RBC_FLAG_USE_LIMIT_LIN_X);
+	RNA_def_property_ui_text(prop, "X Axis", "Limits translation on x axis");
+	RNA_def_property_update(prop, NC_OBJECT | ND_DRAW, "rna_RigidBodyOb_reset");
+
+	prop = RNA_def_property(srna, "use_limit_lin_y", PROP_BOOLEAN, PROP_NONE);
+	RNA_def_property_boolean_sdna(prop, NULL, "flag", RBC_FLAG_USE_LIMIT_LIN_Y);
+	RNA_def_property_ui_text(prop, "Y Axis", "Limits translation on y axis");
+	RNA_def_property_update(prop, NC_OBJECT | ND_DRAW, "rna_RigidBodyOb_reset");
+
+	prop = RNA_def_property(srna, "use_limit_lin_z", PROP_BOOLEAN, PROP_NONE);
+	RNA_def_property_boolean_sdna(prop, NULL, "flag", RBC_FLAG_USE_LIMIT_LIN_Z);
+	RNA_def_property_ui_text(prop, "Z Axis", "Limits translation on z axis");
+	RNA_def_property_update(prop, NC_OBJECT | ND_DRAW, "rna_RigidBodyOb_reset");
+
+	prop = RNA_def_property(srna, "use_limit_ang_x", PROP_BOOLEAN, PROP_NONE);
+	RNA_def_property_boolean_sdna(prop, NULL, "flag", RBC_FLAG_USE_LIMIT_ANG_X);
+	RNA_def_property_ui_text(prop, "X Angle", "Limits rotation around x axis");
+	RNA_def_property_update(prop, NC_OBJECT | ND_DRAW, "rna_RigidBodyOb_reset");
+
+	prop = RNA_def_property(srna, "use_limit_ang_y", PROP_BOOLEAN, PROP_NONE);
+	RNA_def_property_boolean_sdna(prop, NULL, "flag", RBC_FLAG_USE_LIMIT_ANG_Y);
+	RNA_def_property_ui_text(prop, "Y Angle", "Limits rotation around y axis");
+	RNA_def_property_update(prop, NC_OBJECT | ND_DRAW, "rna_RigidBodyOb_reset");
+
+	prop = RNA_def_property(srna, "use_limit_ang_z", PROP_BOOLEAN, PROP_NONE);
+	RNA_def_property_boolean_sdna(prop, NULL, "flag", RBC_FLAG_USE_LIMIT_ANG_Z);
+	RNA_def_property_ui_text(prop, "Z Angle", "Limits rotation around z axis");
+	RNA_def_property_update(prop, NC_OBJECT | ND_DRAW, "rna_RigidBodyOb_reset");
+
+	prop = RNA_def_property(srna, "limit_lin_x_lower", PROP_FLOAT, PROP_UNIT_LENGTH);
+	RNA_def_property_float_sdna(prop, NULL, "limit_lin_x_lower");
+	RNA_def_property_float_default(prop, -1.0f);
+	RNA_def_property_ui_text(prop, "Lower X Limit", "Lower limit of x axis translation");
+	RNA_def_property_update(prop, NC_OBJECT | ND_DRAW, "rna_RigidBodyOb_reset");
+
+	prop = RNA_def_property(srna, "limit_lin_x_upper", PROP_FLOAT, PROP_UNIT_LENGTH);
+	RNA_def_property_float_sdna(prop, NULL, "limit_lin_x_upper");
+	RNA_def_property_float_default(prop, 1.0f);
+	RNA_def_property_ui_text(prop, "Upper X Limit", "Upper limit of x axis translation");
+	RNA_def_property_update(prop, NC_OBJECT | ND_DRAW, "rna_RigidBodyOb_reset");
+
+	prop = RNA_def_property(srna, "limit_lin_y_lower", PROP_FLOAT, PROP_UNIT_LENGTH);
+	RNA_def_property_float_sdna(prop, NULL, "limit_lin_y_lower");
+	RNA_def_property_float_default(prop, -1.0f);
+	RNA_def_property_ui_text(prop, "Lower Y Limit", "Lower limit of y axis translation");
+	RNA_def_property_update(prop, NC_OBJECT | ND_DRAW, "rna_RigidBodyOb_reset");
+
+	prop = RNA_def_property(srna, "limit_lin_y_upper", PROP_FLOAT, PROP_UNIT_LENGTH);
+	RNA_def_property_float_sdna(prop, NULL, "limit_lin_y_upper");
+	RNA_def_property_float_default(prop, 1.0f);
+	RNA_def_property_ui_text(prop, "Upper Y Limit", "Upper limit of y axis translation");
+	RNA_def_property_update(prop, NC_OBJECT | ND_DRAW, "rna_RigidBodyOb_reset");
+
+	prop = RNA_def_property(srna, "limit_lin_z_lower", PROP_FLOAT, PROP_UNIT_LENGTH);
+	RNA_def_property_float_sdna(prop, NULL, "limit_lin_z_lower");
+	RNA_def_property_float_default(prop, -1.0f);
+	RNA_def_property_ui_text(prop, "Lower Z Limit", "Lower limit of z axis translation");
+	RNA_def_property_update(prop, NC_OBJECT | ND_DRAW, "rna_RigidBodyOb_reset");
+
+	prop = RNA_def_property(srna, "limit_lin_z_upper", PROP_FLOAT, PROP_UNIT_LENGTH);
+	RNA_def_property_float_sdna(prop, NULL, "limit_lin_z_upper");
+	RNA_def_property_float_default(prop, 1.0f);
+	RNA_def_property_ui_text(prop, "Upper Z Limit", "Upper limit of z axis translation");
+	RNA_def_property_update(prop, NC_OBJECT | ND_DRAW, "rna_RigidBodyOb_reset");
+
+	prop = RNA_def_property(srna, "limit_ang_x_lower", PROP_FLOAT, PROP_ANGLE);
+	RNA_def_property_float_sdna(prop, NULL, "limit_ang_x_lower");
+	RNA_def_property_range(prop, -M_PI * 2, M_PI * 2);
+	RNA_def_property_float_default(prop, -M_PI_4);
+	RNA_def_property_ui_text(prop, "Lower X Angle Limit", "Lower limit of x axis rotation");
+	RNA_def_property_update(prop, NC_OBJECT | ND_DRAW, "rna_RigidBodyOb_reset");
+
+	prop = RNA_def_property(srna, "limit_ang_x_upper", PROP_FLOAT, PROP_ANGLE);
+	RNA_def_property_float_sdna(prop, NULL, "limit_ang_x_upper");
+	RNA_def_property_range(prop, -M_PI * 2, M_PI * 2);
+	RNA_def_property_float_default(prop, M_PI_4);
+	RNA_def_property_ui_text(prop, "Upper X Angle Limit", "Upper limit of x axis rotation");
+	RNA_def_property_update(prop, NC_OBJECT | ND_DRAW, "rna_RigidBodyOb_reset");
+
+	prop = RNA_def_property(srna, "limit_ang_y_lower", PROP_FLOAT, PROP_ANGLE);
+	RNA_def_property_float_sdna(prop, NULL, "limit_ang_y_lower");
+	RNA_def_property_range(prop, -M_PI * 2, M_PI * 2);
+	RNA_def_property_float_default(prop, -M_PI_4);
+	RNA_def_property_ui_text(prop, "Lower Y Angle Limit", "Lower limit of y axis rotation");
+	RNA_def_property_update(prop, NC_OBJECT | ND_DRAW, "rna_RigidBodyOb_reset");
+
+	prop = RNA_def_property(srna, "limit_ang_y_upper", PROP_FLOAT, PROP_ANGLE);
+	RNA_def_property_float_sdna(prop, NULL, "limit_ang_y_upper");
+	RNA_def_property_range(prop, -M_PI * 2, M_PI * 2);
+	RNA_def_property_float_default(prop, M_PI_4);
+	RNA_def_property_ui_text(prop, "Upper Y Angle Limit", "Upper limit of y axis rotation");
+	RNA_def_property_update(prop, NC_OBJECT | ND_DRAW, "rna_RigidBodyOb_reset");
+
+	prop = RNA_def_property(srna, "limit_ang_z_lower", PROP_FLOAT, PROP_ANGLE);
+	RNA_def_property_float_sdna(prop, NULL, "limit_ang_z_lower");
+	RNA_def_property_range(prop, -M_PI * 2, M_PI * 2);
+	RNA_def_property_float_default(prop, -M_PI_4);
+	RNA_def_property_ui_text(prop, "Lower Z Angle Limit", "Lower limit of z axis rotation");
+	RNA_def_property_update(prop, NC_OBJECT | ND_DRAW, "rna_RigidBodyOb_reset");
+
+	prop = RNA_def_property(srna, "limit_ang_z_upper", PROP_FLOAT, PROP_ANGLE);
+	RNA_def_property_float_sdna(prop, NULL, "limit_ang_z_upper");
+	RNA_def_property_range(prop, -M_PI * 2, M_PI * 2);
+	RNA_def_property_float_default(prop, M_PI_4);
+	RNA_def_property_ui_text(prop, "Upper Z Angle Limit", "Upper limit of z axis rotation");
+	RNA_def_property_update(prop, NC_OBJECT | ND_DRAW, "rna_RigidBodyOb_reset");
+}
+
 void RNA_def_rigidbody(BlenderRNA *brna)
 {
 	rna_def_rigidbody_world(brna);
 	rna_def_rigidbody_object(brna);
+	rna_def_rigidbody_constraint(brna);
 }