To select different types of component simultaneously, first select the components of one type, press Shift while changing the selection filter, and then add the other components to the selection.
Surfaces are one of the basic types of renderable geometry in Softimage. Surfaces can model precise shapes using less geometry than polygon meshes and they’re ideal for smooth, manufactured objects like car and aeroplane bodies.
In Softimage, surfaces are NURBS patches. Mathematically, they are an interconnected patchwork of smaller surfaces defined by intersecting NURBS curves.
Surfaces are also the building blocks of surface meshes, which are described in Surface Meshes.
Surfaces have many components and attributes. You can display these components and attributes in the 3D views and select them for various tasks.
Points are the control points of the curves that define the surface.
You cannot add or remove points directly, but you can add and remove knots as described in Adding Knot Curves and Removing Knot Curves—this has the effect of adding or removing points indirectly.
NURBS hulls (called simply lines in previous versions of Softimage 3D software) are display lines that join consecutive control points. It can be useful to display them when working with curves and surfaces.
Surface knots are the knots of the curves that define the surface; they lie on the surface where the U and V curve segments meet. Knot curves (sometimes called isoparams or isoparms) are sets of connected knots along U or V—they are the “wires” shown in wireframe views. You can select knot curves and use them, for example, to build other surfaces using the Loft operator. You can add and remove knots as described in Adding Knot Curves and Removing Knot Curves.
You cannot transform or deform knots directly.
The minimum and maximum U and V values define the boundaries of a surface. On surfaces that are open in one or both directions, these are the outer edges. You can use the Boundaries selection filter to help you pick boundaries for lofting and other operations.
When working with surfaces, it may be helpful to display NURBS boundaries. This shows the U = 0 boundary in red and the V = 0 boundary in green. This display option is sometimes also called boundary flags or edge flags.
Isolines are not true components. They are, in fact, arbitrary lines of constant U or V on a surface. You can use the U and V Isoline selection filter to help you pick isolines for lofting and other operations.
Surface Curves and Trim Curves
Surface curves and trim curves are components that result when you project a curve object onto a surface. For more information, see Projecting and Trimming with Curves.
Samples
Samples are used to adjust textures on objects. You can select them in the 3D views and manipulate them in the texture editor. For more information, see Working with UVs in the Texture Editor [Texturing].
Subsurfaces
Subsurfaces are the individual NURBS surfaces that are components of assembled surface meshes. For more information, see Surface Meshes.
You can display or hide surface components in the 3D views in exactly the same way as other components and attributes. A quick summary is provided here — for complete details about viewing, see Viewing 3D Objects [Interface and Tools].
To display or hide components in a single 3D view
Do one of the following:
• Click the eye icon (Show menu) and choose the corresponding component option. You can press Shift to keep this menu open while you toggle multiple items.
or
• Press Shift+s, or click the eye icon and choose Visibility Options. The Camera Visibility property editor contains many more options than the menu, for both selected and unselected objects.
To display or hide components in all open 3D views
Do one of the following:
• Choose Display on the main menu and then choose the corresponding component option.
or
• Choose Display > Visibility Options (All Cameras). The Camera Visibility property editor contains many more options than the menu, for both selected and unselected objects.
You select surface components in exactly the same way as anything else in Softimage: using the selection filters, tools, and modes available on the Select panel. Selection is fully described in Selecting [Scene Elements] and is quickly summarized here.
In addition, this section describes some special selection commands as they relate to surface components: Select U/V Rows and Select Adjacent Points.
To select components
1. Select the object that owns the components you want to select.
To select components on multiple objects, select all the associated objects first.
2. Set the selection filter to the desired component type — see Summary of selection filters.
3. If desired, change the selection tool — see Summary of selection tools.
4. Click and drag on the components in a 3D view.
The specific mouse buttons and modifier keys that you use to perform different actions — like selecting, adding to the selection, toggling, and deselecting — depend on the selection interaction model.
For complete details, see Selecting Components Using the Different Interaction Models [Scene Elements].
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To select different types of component simultaneously, first select the components of one type, press Shift while changing the selection filter, and then add the other components to the selection. |
Component selection filters determine what type of component you can select on the active geometric objects. The most commonly used filters are available as buttons on the Select panel, while more filters are available from the Filter menu below the buttons.
The component selection filters are context-sensitive; they change depending on what type of object is active. The illustration above shows the component filters available when a surface object is selected.
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There is an additional filter on the Filter menu that allow you to select border points. This is an example of custom a filter. For information about creating your own filters, see the SDK Guide. |
The selection tools determine the mouse interaction used select objects. You can activate a selection tool with the items on the Select > Tools menu. Alternatively, you can press one of the following keys:
• F7 for the Rectangle selection tool.
• F8 for the Lasso selection tool.
• F9 for the Freeform selection tool.
• F10 for the Raycast selection tool.
• Shift+F10 for the Rectangle-Raycast tool.
• F11 for the Paint selection tool (for surfaces, this works with points only).
Selection modes
Selection modes are a combination of a filter and tool mapped to a single key for convenience. The only component selection mode that is useful for surface components is t for the Rectangle Point.
• With one or more points on a surface selected, choose Select > Select Adjacent > Points.
Selecting Rows of Points in U or V
You can use the loop selection feature of the selection tools to select rows of control points or knot points in U or V on NURBS surfaces.
The procedures are described below. For more in formation about the loop selection feature in general, see Selecting Ranges and Loops of Components [Scene Elements].
There are different procedures depending on the component selection model you have chosen. For more information about component selection model, see Selecting Components Using the Different Interaction Models [Scene Elements].
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• The U and V rows stop at the boundaries between subsurfaces on assembled surface meshes. • You cannot use the Paint selection tool with the loop selection. |
If Extended Component Selection is off
If both Select > Extended Component Selection and SI|3D Selection Model are off:
1. Do one of the following:
- Select one point, then Alt+middle-click another point on the same row.
or
- Alt+middle-click to select two points on the same row with a single mouse movement.
2. Repeat to modify the selection. Use any of the following additional modifier keys:
- Press Shift to add to the selection.
- Press Ctrl to toggle-select.
- Press Ctrl+Shift to deselect.
If Extended Component Selection is on
If either or both of Select > Extended Component Selection and SI|3D Selection Model are on:
1. Do one of the following:
- Select one point, then Ctrl+click another point on the same row.
or
- Ctrl+click to select two points on the same row with a single mouse movement.
2. Repeat to modify the selection. Use the following mouse buttons:
- Use the left mouse button to add to the selection.
- Use the middle mouse button to deselect.
- Use the right mouse button to toggle-select.
Autodesk Softimage v.7.5