SixDOF Subobjects¶
A SixDOF vehicle type may include one or more subobjects that may represent bombs, missiles, fuel tanks, etc. Subobjects do not have an AFSIM platform until they are jettisoned. At that time, a platform will be created containing a WSF_RIGID_BODY_SIX_DOF_MOVER or WSF_POINT_MASS_SIX_DOF_MOVER and relevant data for the jettisoned vehicle will be passed into the mover, automatically transferring to the platform its kinematic state. See map_vehicle_to_platform for more information.
A WSF_RIGID_BODY_SIX_DOF_MOVER may contain WSF_POINT_MASS_SIX_DOF_MOVER subobjects, and vice versa. This permits use cases where the fidelity of a jettisoned vehicle is more (or less) important than the model fidelity of the launching vehicle.
- subobject <name> <derived_from_type_name> … end_subobject¶
Depending on the defining data, subobjects may effect the performance of their parent platform. For example, a bomb carried on an external pylon may produce additional drag on the parent. It is also possible for a subobject to contribute thrust forces to the parent (such as running Hound Dog missiles on a B-52 during takeoff, or having SRB thrust contribute to the total thrust of a Space Shuttle orbiter). In addition, subobjects will contribute mass properties and inertia to their parent.
A subobject is always derived from a previously defined vehicle type. Although any parameter can be overridden, typical use involves setting relative positioning and separation effects for a subobject while using all other characteristics from the object type from which it was derived.
subobject missile1 AIM9L // Relative Positioning with Parent parent_rel_x ... parent_rel_y ... parent_rel_z ... parent_rel_yaw ... parent_rel_pitch ... parent_rel_roll ... // Separation Effects separation_vx ... separation_vy ... separation_vz ... separation_omega_x ... separation_omega_y ... separation_omega_z ... end_subobject
Relative Positioning with Parent¶
The following commands specify how a subobject should be positioned relative to its parent while captive.
- parent_rel_x <length-value>¶
This specifies the x-location of the object’s reference point relative to the parent’s reference point using the parent’s body coordinate system.
Default: 0.0
- parent_rel_y <length-value>¶
This specifies the y-location of the object’s reference point relative to the parent’s reference point using the parent’s body coordinate system.
Default: 0.0
- parent_rel_z <length-value>¶
This specifies the z-location of the object’s reference point relative to the parent’s reference point using the parent’s body coordinate system.
Default: 0.0
- parent_rel_yaw <angle-value>¶
This specifies the yaw of the object about its reference point relative to the parent’s body coordinate system.
Default: 0.0
- parent_rel_pitch <angle-value>¶
This specifies the pitch of the object about its reference point relative to the parent’s body coordinate system.
Default: 0.0
- parent_rel_roll <angle-value>¶
This specifies the roll of the object about its reference point relative to the parent’s body coordinate system.
Default: 0.0
Separation Effects¶
The following commands specify the perturbation that will be applied to a subobject when it is jettisoned from its parent.
- separation_vx <length-value>¶
This specifies the x-component of velocity (in parent body coordinates) that is imparted to the subobject when it separates from the parent.
Default: 0.0
- separation_vy <length-value>¶
This specifies the y-component of velocity (in parent body coordinates) that is imparted to the subobject when it separates from the parent.
Default: 0.0
- separation_vz <length-value>¶
This specifies the z-component of velocity (in parent body coordinates) that is imparted to the subobject when it separates from the parent.
Default: 0.0
- separation_omega_x <length-value>¶
This specifies the x-component of angular velocity (in subobject body coordinates) that is imparted to the subobject when it separates from the parent.
Default: 0.0
- separation_omega_y <length-value>¶
This specifies the y-component of angular velocity (in subobject body coordinates) that is imparted to the subobject when it separates from the parent.
Default: 0.0
- separation_omega_z <length-value>¶
This specifies the z-component of angular velocity (in subobject body coordinates) that is imparted to the subobject when it separates from the parent.
Default: 0.0
Return to six_dof_object_types, rigid_body_vehicle_type, point_mass_vehicle_type
