Surfaces

1. From the Model Browser, select the system to which the surface is to be added.
2. Right-click on a system in the Model Browser and select Add > Reference Entity > Surface from the context menu.
   OR
   Right-click on a curve folder in the Model Browser and select Add Surface from the context menu.
   OR
   Right-click the Surfaces button on the Reference toolbar.
   The Add Surface dialog is displayed.
3. Specify a label and variable name.
   By default, variables names of entities in MotionView follow a certain convention. For example, all deformable surface entities have a variable name starting with “sur_”. This is the recommended convention to follow when building models in MotionView since it has many advantages in model editing and model manipulation.
4. Click OK to close the window or Apply to continue creating entities.

The surface entity allows you to describe a parametric surface for use with advanced joints like point to surface joints, curve to surface joints, and the surface to surface joints. The surface can be described by a user subroutine for the MotionSolve and ADAMS solvers, and by a Parasolid reference for the ADAMS solver.

1. If the Surfaces panel is not currently displayed, select the desired surface by clicking on it in the Model Browser or in the modeling window.
   The Surfaces panel is automatically displayed.
2. From the Connectivity tab, select an option from the first drop-down menu.
   • Open in U - Select if the two ends of the surface in the U direction will be am open surface.
   • Closed in U - Select if the two ends of the surface will be close in the U direction.
3. Similarly, define the V direction from the second drop-down menu.

If desired, define the output using the User-Defined tab, which will allow you to specify the properties of the surface using user subroutines.

1. From the Connectivity tab, activate the User-defined properties option.
2. Click the Properties tab.
3. Enter the initial and final values in the U and V directions.
4. Click the User-Defined tab.
5. Define the user subroutine.
   1. Provide an expression with the USER solver function with parameters being passed to the user subroutine.
   2. Alternatively, activate the Use local file and function name check box to specify a local file where the subroutine code can be accessed by the solver.
      If this option is not specified, MotionSolve will search for a subroutine following its user subroutine loading rules.
   3. Select a function type from the drop-down menu.
   4. Select the local file for the subroutine.
      The type of file to be specified will depend on the selected function type. For example, if DLL/SO is selected, you can specify a file with a .dll extension (for Windows) or an .so extension (for Linux).
   5. Specify the function name in the subroutine that defines the entity, or accept the default name provided by MotionView.