Primitives

A primitive is a simple geometric shape defined using hard points and vectors. Examples include a box, cylinder, or sphere.

It can be defined as a pair entity, which helps in creating models that have identical entities across the x-z plane. The pair entity can have asymmetric or symmetric properties. When symmetric, the properties from one side are mirrored to the other side about the x-z plane.

Add a Primitive

Create a primitive using a hard point as the origin and, when applicable, using one or more hard points or a vector to define the orientation.

  1. On the Motion ribbon, under Profile, select Analyst.

  2. Under Create, select the Primitives tool.
    Tip: To find and open a tool, press Ctrl+F. For more information, see Find and Search for Tools.
    The guide panel is displayed.
    Figure 1.


  3. Optional: To select a Parent system, click the Advanced selector ....
    Note: If a system or an entity in a system is selected before entering an entity context, the system is preselected as the parent.
  4. Optional: Edit the Label.
  5. Optional: To create a pair of entities, turn on Pair.
    • To create a model that is symmetric about the x-z plane, in the Property Editor, under General, set Symmetry to Left or Right.
    • To create a model that is asymmetric, set Symmetry to None.
  6. Choose a Shape:
    • Cylinder
    • Box
    • Sphere
  7. Resolve the References:

    For a Cylinder:

    1. Select an Origin, which is one end of the cylinder, using one of the following methods.
      • In the modeling window, select an existing hard point.
      • Select a vertex, edge, or face of a geometry. This will automatically create a new hard point. When an edge or face is selected, the point is created at the center of the edge or face.
      • Click the Advanced Selector … and make your selection in the Model Tree.
      • To select the global origin, click Ground .
    2. Define the Alignment to orient the cylinder along its length.
    Table 1.
    To use this Alignment method Do this
    Point Do one of the following:
    • In the modeling window, select an existing hard point.
    • Select a vertex, edge, or face of a geometry. This will automatically create a new hard point. When an edge or face is selected, the point is created at the center of the edge or face.
    • Click the Advanced Selector … and make your selection in the Model Tree.
    • To select the global origin, click Ground .
    Vector Do one of the following:
    • In the modeling window, select an existing vector.
    • Select an edge or circular face of a geometry. A vector is created along the edge or center of the face. A hard point is also created for the vector origin.
    • Click the Advanced Selector … and make your selection in the Model Tree.
    • To select the global origin, click Ground .

    For a Box:

    1. Select a Type.
      • Center: The origin of the box's coordinate system origin is at the center.
      • Corner: The origin of the box's coordinate system origin is at a corner.
      • Face Center: The box is defined using 2 points that form one set of opposite faces.
    2. Select an Origin using one of the following methods.
      • In the modeling window, select an existing hard point.
      • Select a vertex, edge, or face of a geometry. This will automatically create a new hard point. When an edge or face is selected, the point is created at the center of the edge or face.
      • Click the Advanced Selector … and make your selection in the Model Tree.
      • To select the global origin, click Ground .
    3. Select the directions.

      For Center and Corner:

      1. To orient the box, select a Direction:
        • X Axis
        • Y Axis
        • Z Axis
      2. Define the Alignment.
        To use this Alignment method Do this
        Point Do one of the following:
        • In the modeling window, select an existing hard point.
        • Select a vertex, edge, or face of a geometry. This will automatically create a new hard point. When an edge or face is selected, the point is created at the center of the edge or face.
        • Click the Advanced Selector … and make your selection in the Model Tree.
        • To select the global origin, click Ground .
        Vector Do one of the following:
        • In the modeling window, select an existing vector.
        • Select an edge or circular face of a geometry. A vector is created along the edge or center of the face. A hard point is also created for the vector origin.
        • Click the Advanced Selector … and make your selection in the Model Tree.
        • To select the global origin, click Ground .
      3. Select another Direction. Based on the first direction, select one plane among the two listed. For example, if the Z axis was selected earlier, then ZX Plane and ZY Plane can be selected.
      4. Define the Alignment.
        To use this Alignment method Do this
        Point Do one of the following:
        • In the modeling window, select an existing hard point.
        • Select a vertex, edge, or face of a geometry. This will automatically create a new hard point. When an edge or face is selected, the point is created at the center of the edge or face.
        • Click the Advanced Selector … and make your selection in the Model Tree.
        • To select the global origin, click Ground .
        Vector Do one of the following:
        • In the modeling window, select an existing vector.
        • Select an edge or circular face of a geometry. A vector is created along the edge or center of the face. A hard point is also created for the vector origin.
        • Click the Advanced Selector … and make your selection in the Model Tree.
        • To select the global origin, click Ground .
      The images below show how these two types of boxes are oriented. The box's coordinate system is oriented so that the selected axis is aligned to the first alignment entity (point or vector) and the second axis forming the selected plane is oriented so that the second alignment entity is on that plane.

      Table 2. Center and Corner Boxes
    For Face Center:
    1. Select Origin 2 using one of the following methods.
      • In the modeling window, select an existing hard point.
      • Select a vertex, edge, or face of a geometry. This will automatically create a new hard point. When an edge or face is selected, the point is created at the center of the edge or face.
      • Click the Advanced Selector … and make your selection in the Model Tree.

        This is sets the Z axis of the coordinate system along the selected point, with length in Z direction being the distance between Origin and this point.

    2. Select the other direction by selecting either ZX Plane or ZY Plane
    3. Define the Alignment.
      To use this Alignment method Do this
      Point Do one of the following:
      • In the modeling window, select an existing hard point.
      • Select a vertex, edge, or face of a geometry. This will automatically create a new hard point. When an edge or face is selected, the point is created at the center of the edge or face.
      • Click the Advanced Selector … and make your selection in the Model Tree.
      • To select the global origin, click Ground .
      Vector Do one of the following:
      • In the modeling window, select an existing vector.
      • Select an edge or circular face of a geometry. A vector is created along the edge or center of the face. A hard point is also created for the vector origin.
      • Click the Advanced Selector … and make your selection in the Model Tree.
      • To select the global origin, click Ground .
    The orientation of the Face Center box is shown below.
    For a Sphere, select an Origin, which is the center of the sphere, using one of the following methods.
    • In themodeling window, select an existing hard point.
    • Select a vertex, edge, or face of a geometry. This will automatically create a new hard point. When an edge or face is selected, the point is created at the center of the edge or face.
    • Click the Advanced Selector … and make your selection in the Model Tree.
    • To select the global origin, click Ground .
  8. Click Apply to create the entity and edit it further. For more information, see Edit a Primitive, or click OK to exit the tool on entity creation.

    The primitive entity is created. It is now listed in the Model Browser and its properties appear in the Property Editor.

  9. Right-click and mouse through the check mark to exit, or double-right-click.

Edit a Primitive

Edit a primitive part using the Primitives tool or Property Editor.

  1. Select the primitive.
  2. Choose from the following methods:
    Table 3.
    To use this method Do this
    Primitives tool
    1. On the Motion ribbon, under Profile, select Analyst.

    2. Under Create, select the Primitives tool.


      The guide panel is displayed. Manipulators appear around the primitive.
      Figure 2.


      Example: The Cylinder primitive appears as shown below in Edit mode.
      Figure 3.


    3. Edit the Label or any References from the guide panel. Follow instructions in Add a Primitive for selecting References.
    4. Drag the manipulators to edit dimensions such as the Radius or Length.
    5. Right-click and mouse through the check mark to exit, or double-right-click. Or click Cancel in the guide panel.
    Property Editor The selected primitive's properties are listed in the Property Editor. Refer to Primitive Properties.

Primitive Properties

Descriptions of primitive properties in the Property Editor.

Table 4.
Property Description
General
Name The entity's name
Variable Name The variable name, a unique identifier string of the entity
ID A unique identifying integer
Ground Ground the part.
Rigid Group Read-only. The rigid group name, if the primitive is part of a rigid group.
Material Assign a material to the primitive.
Appearance
Color Assign a color to the primitive.
Transparency Set the transparency level for displaying parts from 0 to 100%.
Geometric Properties
Cylinder
Origin The center of one of the cylinder's bases.
Align Method The length of the cylinder can be assigned to a reference geometry:
  • Point
  • Vector
Point (Alignment) Point indicating the orientation. Active only if the Align Method is Point.
Vector (Alignment) Vector indicating the orientation. Active only if the Align Method is Vector.
Autolength Set the cylinder length as the distance between the Origin and the Alignment Point. Applicable when the Align Method is Point.
Length The cylinder's length. Applicable when the Align method is Vector and Autolength is turned off.
Radius 1 The radius of the cylinder base containing the origin.
Radius 2 The radius of the opposite cylinder base, which doesn't contain the origin. By default, the value is 1.
Box
Origin The box's origin.
Type The box type:
  • Center
  • Corner
  • Face Center
Direction (1) First directional axis to orient:
  • X Axis
  • Y Axis
  • Z Axis
(Only applicable to Center and Corner boxes.)
Method 1 Method of orienting direction. Point or Vector. (Only applicable to Center and Corner boxes.)
Point 1 Active only if Method 1 is Point. Point indicating the direction of the selected axis from the Origin. (Only applicable to Center and Corner boxes.)
Vector 1 Active only if Align Method 1 is Vector. Vector indicating the direction of the selected axis from the origin. (Only applicable to Center and Corner boxes.)
Direction (2) Plane to orient based on the Direction 1 selection. XY | XZ | YX | YZ | ZX| ZY. For a Face Center box, only ZX | ZY planes are available.
Method 2 Method of orienting the plane. Point or Vector.
Point 2 Active only if Align Method 2 is Point. Point indicating direction of the plane such that the selected point lies in the plane.
Vector 2 Active only if the Align Method is Vector. Vector indicating the direction of the plane such that the selected vector lies in the plane.
Origin 2 Applicable to Face Center. Indicates the point on the opposing face from the origin. The z-axis of the box system is oriented in along this point.
Length X The length in the X direction
Length Y The length in the Y direction
Length Z The length in the Z direction
Sphere
Origin The origin of the sphere
Radius The radius of the sphere
Mass Properties Read-only when Override is turned off.
Override Override the auto-calculated mass, inertia, and center of mass based on the geometry and assigned material.
Mass Mass of the primitive
Ixx Moment of inertia about the x-axis
Iyy Moment of inertia about y-axis
Izz Moment of inertia about z-axis
Ixy Product inertia about the XY plane
Ixz Product inertia about the XZ plane
Iyz Product inertia about the YZ plane
Note: The mass moment of inertia values are provided with respect to the Center of Mass coordinate system.
Center of Mass Center of Mass coordinate system (CM Marker) information
Override Available when Override under Mass Properties is turned on. Turn this option on to select a different origin and orientation for CM marker. When this option is off, the CM marker is at Global Frame.
Coordinates Read-only and available only when the Mass Properties Override option is off.
X X coordinate of center of mass
Y Y coordinate of center of mass
Z Z coordinate of center of mass
Point Available only if Override is turned on. Origin point of the CM marker.
Orientation Read-only when the Mass Properties Override option is turned off
Orientation Method Method of orienting the center of mass coordinate system:
  • 1 Axis
  • 2 Axis
  • Orient by Angles
1st Axis First directional axis to orient the CM Marker
Direction Select X Axis, Y Axis, or Z Axis.
Alignment Method Method of orienting direction. Point, Vector, or DxDyDz (Direction Cosines)
Point Active only if the Alignment Method is Point. Point indicating the direction of the selected axis from the Origin.
Vector Active only if the Alignment Method is Vector. Vector indicating the direction of the selected axis from the origin.
Dx Active only if the Alignment Method is DxDyDz. Direction Cosine value in Global X direction
Dy Active only if the Alignment Method is DxDyDz. Direction Cosine value in Global Y direction
Dz Active only if the Alignment Method is DxDyDz. Direction Cosine value in Global Z direction
2nd Axis Second directional axis to orient the CM Marker.
Direction Plane to orient based on the Direction of 1st Axis selection. XY | XZ | YX | YZ | ZX| ZY. For a Face Center box, only ZX | ZY plane are available.
Alignment Method Method of orienting direction. Point, Vector, or DxDyDz (Direction Cosines)
Point Active only if the Alignment Method is Point. Point indicating direction of the plane such that the selected point lies in the plane.
Vector Active only if the Alignment Method is Vector. Vector indicating direction of the plane such that the selected vector lies in the plane.
Dx Active only if the Alignment Method is DxDyDz. Direction Cosine value in Global X direction
Dy Active only if the Alignment Method is DxDyDz. Direction Cosine value in Global Y direction
Dz Active only if the Alignment Method is DxDyDz. Direction Cosine value in Global Z direction
Note: When orienting the plane using DxDyDz, the plane is oriented such that the resulting vector of Dx, Dy and Dz lies in the plane.
Initial Conditions Set initial velocity conditions for the primitive.
Translational Velocity Set initial velocity conditions for the primitive along the translational direction.
User-defined VM Turn on this option to provide a reference marker for translational velocities. When this option is off, the reference marker is Global Frame.
Marker Reference frame for translation velocities
Vx Flag to specify the initial velocity along X
Vx Initial velocity value along X
Vy Flag to specify the initial velocity along Y
Vy Initial velocity value along Y
Vz Flag to specify initial velocity along Z
Vz Initial velocity value along Z
Rotational Velocity Set the initial velocity conditions for the primitive about the rotational direction.
User-defined VM Turn on this option to provide a reference marker for rotational velocities. When this option is off, the reference marker is the part's CM marker.
Wm Reference frame for rotational velocities
Wx Flag to specify initial velocity about X
Wx Initial velocity value about X
Wy Flag to specify initial velocity about Y
Wy Initial velocity value about Y
Wz Flag to specify the initial velocity about Z
Wz Initial velocity value about Z
Motion Contact
Flip material side Flip the side of contact.
Autocalculate resolution Use the default resolution for tessellation when used in Motion contact (Medium).
Resolution When Autocalculate resolution is turned off, choose a resolution from Very Low to Very High.