PolyNURBS Edit Mode

Double-click a PolyNURBS object to enter edit mode. You can then use Nurbify to visualize the object as a NURBS surface or polymesh, and edit the vertices, edges, or faces to modify the shape.

Nurbify

Visualize the PolyNURBS object as a NURBS surface or polymesh, or vice versa.

Generally NURBS surfaces are more precise and flexible, while polygonal models are simpler. You may need to work with polygons when importing polygonal models from other 3D software programs.

  1. Double-click a PolyNURBS object to enter edit mode.
  2. Do one of the following:
    • To visualize the object as a NURBS surface, select Nurbify in the Control Panel.
    • To visualize the object as a polymesh, clear the Nurbify check box in the Control Panel.
    Tip: You can also activate or deactivate Nurbify by pressing N.
  3. Right-click and mouse through the check mark to exit, or double-right-click.
If you activated Nurbify, when you exit the PolyNURBS tool, the cage is hidden and you'll see only the NURBS object.

Edit Vertices

Edit vertices to modify the shape of the PolyNURBS.

  1. Double-click a PolyNURBS object to enter edit mode.
  2. To enter vertex editing mode:
    • Press A.
    • In the guide bar, click Vertices .
  3. Configure the display:
    • To display the x-axis, y-axis, or z-axis, under Symmetry, click X, Y, or Z. If you don't want to display any axes, click None.
    • To define the Tessellation, select View or a preset.
  4. Select the vertices you want to edit.
    Note: A vertex is selectable if it's attached to an edge that belongs to at most two faces; when you hover over a selectable vertex, it will turn from blue to yellow.
    To Do this
    Select one vertex Click the vertex.
    Select multiple vertices
    • Use box selection.
    • Hold down Ctrl while clicking the vertices.
    • Right-click the PolyNURBS object, and then click one of the following options:
      • Select All Vertices
      • Deselect All Vertices
      • Invert Selection: Clear the current selection and select the other vertices.
      • Select Boundaries: Select all boundary vertices.
    Select all the vertices of one or more edges
    1. Press S to enter edge editing mode.
    2. Select one or more edges.
    3. Then press A to select all corresponding vertices.
    Select all the vertices of one or more faces
    1. Press D to enter face editing mode.
    2. Select one or more faces.
    3. Then press A to select all corresponding vertices.
    Create a selection group
    1. Click the chevron next to Selection Groups/Morph.
    2. Select the vertices you want to group together.
    3. Click . The group is automatically named Group 1, Group 2, etc., but you can change the name by clicking the text box twice and then typing a name.
    To morph a selection group, see the next step.
    The x-, y-, and z-coordinates of the most recently selected vertex is displayed at the top of the Control Panel.
  5. Edit the selected vertices.
    To Do this Note
    Move the selected vertices
    • Drag the selected vertices.
    • When a vertex is selected, the Mini Move tool automatically appears. Hover over a manipulator to display a tooltip describing what you can do by dragging the manipulator. Drag the desired manipulator to translate, scale, or rotate the vertex.

    To turn off the Mini Move tool, deselect Mini Move tool in the Control Panel.
    Slide the selected vertices along an edge Hover around one of the selected vertices, and then drag one of the arrows.  
    Align a surface or a row of vertices to a curve
    1. In the Control Panel, select Align to Curve.
    2. For Entity to align to curve, select one of the following options:
      • Surface (default)
      • Vertices
    3. Select one of the following options:
      • Pick curve : Select a curve to which you want to align the selected vertices.
      • Auto - 2 CVs : Align the selected vertices to an automatically created curve. The number of vertices will change to two.
      • Auto - 3 CVs : Align the selected vertices to an automatically created curve. The number of vertices will change to three.
      • Auto - 5 CVs : Align the selected vertices to an automatically created curve. The number of vertices will change to five.
      • Auto - 7 CVs : Align the selected vertices to an automatically created curve. The number of vertices will change to seven.
      • Auto - 9 CVs : Align the selected vertices to an automatically created curve. The number of vertices will change to nine.
    4. To constrain alignment to a specific direction:
      1. Click Top , Front , Right or .
      2. To project the vertices onto the curve along the minimum distance from the curve, click Min. Distance .
      3. Click the Align to Curve button.
    5. To align a new row of vertices to a curve, click the New Selection button.
    Instead of moving individual vertices to create a curved line, you can align a surface or a row of vertices to an existing curve or to an automatically created curve (for more control over the shape, select a curve with more vertices). When you move a vertex on the resulting curve, the other vertices move automatically.
    Chamfer vertices
    1. Right-click, and then select Chamfer.
    2. To resize a chamfer, move the mouse along one of the edges close to the vertex until the chamfer graphic is displayed.
    3. Deselect the vertices to end the chamfer.
     
    Delete the selected vertices
    • Press Delete.
    • Right-click the PolyNURBS object, and then click Delete Selected Vertices.
    This nondestructive operation doesn't create holes and has two use cases:
    • To weld connected faces, delete an internal vertex, welding the surrounding faces into a single face.
    • To remove corners, delete an internal or external vertex that is connected to exactly two edges, merging the surrounding two edges into a single edge. The two adjoining edges collapse into one edge that connects the two neighboring vertices.
    Weld the selected boundary vertices
    1. To weld selected vertices only if the distance between the two farthest apart points is lower than a specified tolerance value, in the Control Panel, enter a Tolerance.
    2. Click the Weld Selected button.
    Use this option to connect separate PolyNURBS objects or remove spikes.
    Morph a selection group
    1. To select a group for morphing, turn on the checkbox. At the top of the Control Panel, the Normal, Morph, and Evaluate buttons appear.
    2. In the Control Panel, under Active morph, select the group you want to morph. In Morph mode, only the vertices in the group are displayed; the others are hidden.
    3. To morph the selected group, drag it in the modeling window.
    To evaluate the difference between the Normal and Morph modes:
    1. Click the Evaluate button.
    2. To evaluate a group, enter a value from 0 to 100 to see the group morphed from 0 to 100%.
  6. Optional: Change how the vertices are displayed.
    To Do this Note
    Show the normals of all the vertices Right-click the PolyNURBS object, and then click Show Normal. Use this option to verify that the normals are oriented in the correct direction.
    Hide the selected vertices and associated faces Right-click the PolyNURBS object, and then click Hide Selected (Faces).  
    Hide the unselected vertices and associated faces Right-click the PolyNURBS object, and then click Hide Unselected (Faces).  
    Show all faces, edges, and vertices Right-click the PolyNURBS object, and then click Show All.  
  7. Right-click and mouse through the check mark to exit, or double-right-click.

Edit Edges

Edit edges to modify the shape of the PolyNURBS.

  1. Double-click a PolyNURBS object to enter edit mode.
  2. To enter edge editing mode:
    • Press S.
    • In the guide bar, click Edges .
  3. Configure the display:
    • To display the x-axis, y-axis, or z-axis, under Symmetry, click X, Y, or Z. If you don't want to display any axes, click None.
    • To define the Tessellation, select View or a preset.
  4. Select the edges you want to edit.
    To Do this
    Select one edge Click the edge.
    Select multiple edges
    • Hold down Ctrl while clicking the vertices
    • Right-click the PolyNURBS object, and then select one of the following options:
      • Select All Edges
      • Deselect All Edges
      • Invert Selection: Clear the current selection and select the other edges.
      • Select Boundaries: Select all boundary edges
      • Advanced Selection: To select/deselect an edge loop, hover near the end of an edge and click the arrow.
    Select an adjacent loop of edges
    1. Right-click the PolyNURBS object, and then click Adjacent Loop.
    2. To select the adjacent loop, move the mouse to the midpoint on the edge until the arrow is visible. Click the arrow on either side of the edge to select respective loop.
    3. Click Exit Adjacent Loop mode.
    Select the tiny edges In the Control Panel, click the Select Tiny Edges button.

    To redefine just how short the edges have to be in order to be considered "tiny," adjust the Tiny Threshold.

    Select adjacent edges with the same creasing value
    1. Select an edge.
    2. Right-click, and then select Select by Creasing.
    Adjacent edges with the same creasing value are selected. Now you can change the creasing value of these edges simultaneously.
    Create a selection group
    1. Click the chevron next to Selection Groups.
    2. Select the edges you want to group together.
    3. Click . The group is automatically named Group 1, Group 2, etc., but you can change the name by clicking the text box twice and then typing a name.
  5. Edit the selected edges.
    To Do this Note
    Move and scale the selected edges
    • Drag the selected edge.
    • When an edge is selected, the Mini Move tool automatically appears. Hover over a manipulator to display a tooltip describing what you can do by dragging the manipulator. Drag the desired manipulator to translate, scale, or rotate the edge.

    To turn off the Mini Move tool, deselect Mini Move tool in the Control Panel.
    Pull selected edges Drag one of the selected edges.  
    Extrude selected edges
    1. Do one of the following:
      • To extrude freely, press Alt, and drag the arrow.

      • To extrude selected edges freely in the same direction, hold down Ctrl instead of Alt while dragging.

        (When you extrude multiple edges, by default each edge is extruded along its own tangent direction to better maintain the PolyNURBS object's original shape. However, this may lead to undesired results, such as overlapping edges.)

      • To extrude perpendicular or parallel to the selected edge, hold down Alt+Shift and drag. The dotted red line indicates that you are snapping along the perpendicular or parallel direction.

    2. Optional: Enter a precise length in the microdialog. Click Done.
    You can extrude edges that are attached to a face on only one side; you cannot extrude interior edges.
    Chamfer selected edges
    1. Mouse over the midpoint of a selected edge until a tooltip appears.
    2. Do one of the following:
      • To chamfer, hold down Alt until the chamfer graphic is seen. Click and drag.

      • To double chamfer, hold down Alt+Shift while dragging.
    You can chamfer interior edges.
    Slide the selected edge Mouse over the selected edge until the dotted yellow Slide edge handle appears, then click and drag. You can slide edges inward, outward, up, and down. Widen or narrow a selected edge loop around its eye; each edge in the loop will be repositioned relative to its original position.

    While the Translate tool could be used to move an edge, it is generally better to use the Slide edge handle, as it was specifically designed for repositioning PolyNURBS edges without distorting the geometry.

    Original PolyNURBS object

    Click and drag the selected edge and red dotted line appears to show slide direction. The sliding is view dependent.

    Sharpen or smooth edges If Nurbify is deactivated, Creasing (Shading) is available.
    1. Select one of the following options:
      • Sharp: Make the selected edges appear sharper.
      • Smooth: Make the selected edges appear softer, giving the illusion of a continual, smooth surface.
    2. To adjust the smoothing threshold, enter a Smoothing Angle. The smoothing effect will be applied only to edges whose adjacent faces determine an angle higher than this number.
    This is a shading effect that does not affect the actual shape of the PolyNURBS.
    Sharpen or smooth edges (change surface geometry) If Nurbify is activated, Creasing (Surface) is available. This actually changes the surface geometry.
    1. Select Sharp to make the selected edges appear sharper.
    2. Strength: After selecting the desired edges on the cage, adjust this value to sculpt edges along the nurbified object in the corresponding locations. Increase the value for sharper edges; decrease the value for softer edges. (0 corresponds to no creasing, while 1 responds to maximum creasing).
    The blue color along the edges of the cage indicates where creasing was applied.

    Only open edges can be bridged and the number of edges should be equal on both sides.

    Delete selected edges Remove an edge, merging the two adjacent faces.  
    Delete selected edge loops Hold Shift to select the edge loop first. Use ALT to select a loop.
    Collapse selected edges To remove a selected edge, collapsing the two endpoints into a single vertex, use right-click. This option is useful for fixing tiny edges or edges with internal vertices. See Fix Geometry.  
    Bridge selected edges To create a new face between selected edges, use right-click. In addition, you can choose from the following options:
    • Invert Direction: If bridging occurred in the wrong direction, you can use this button to correct it.
    • Rotate Forward: If one of the selected edges is a closed loop, shift the new faces one vertex forward.
    • Rotate Backward: If one of the selected edges is a closed loop, shift the new faces one vertex backward.
    • Use right-click "Bridge" (no shortcut available)
    Only open edges can be bridged and the number of edges should be equal on both sides.
  6. Optional: Change how the edges are displayed.
    To Do this Note
    Hide the selected edges and associated faces Right-click the PolyNURBS object, and then click Hide Selected (Faces).  
    Hide the unselected edges and associated faces Right-click the PolyNURBS object, and then click Hide Unselected (Faces).  
    Show all faces, edges, and vertices Right-click the PolyNURBS object, and then click Show All.  
  7. Right-click and mouse through the check mark to exit, or double-right-click.

Edit Faces

Edit faces to modify the shape of the PolyNURBS.

  1. Double-click a PolyNURBS object to enter edit mode
  2. To enter face editing mode:
    • Press D.
    • In the guide bar, click Faces .
  3. Configure the display:
    • To display the x-axis, y-axis, or z-axis, under Symmetry, click X, Y, or Z. If you don't want to display any axes, click None.
    • To define the Tessellation, select View or a preset.
  4. Select the faces you want to edit:
    To Do this
    Select one face Click the face.
    Select multiple faces
    • Use box selection.
    • Hold down Ctrl and click the faces.
    • Right-click the PolyNURBS object, and then select one of the following options:
      • Select All Faces
      • Deselect All Faces
      • Invert Selection: Clear the current selection and select the other faces.
      • Select Boundaries: Select all boundary faces.
      • Advanced Selection: To select/deselect a loop of faces, hover near the edge of a face and click the arrow.
    Select an adjacent loop of faces
    1. Right-click the PolyNURBS object, and then click Adjacent Loop.
    2. Move mouse to the center of one of the selected faces to loop arrows. Click one of the arrows to select/deselect an adjacent loop.
    3. Click Exit Adjacent Loop mode.
    Select tiny faces In the Control Panel, click the Select Tiny Faces button.

    To redefine just how small the faces have to be in order to be considered "tiny," adjust the Tiny Threshold.

    Create a selection group
    1. Click the chevron next to Selection Groups.
    2. Select the edges you want to group together.
    3. Click . The group is automatically named Group 1, Group 2, etc., but you can change the name by clicking the text box twice and then typing a name.
  5. Edit the faces:
    To Do this Note
    Move and scale selected faces
    • Drag the selected faces.
    • When a face is selected, the Mini Move tool automatically appears. Hover over a manipulator to display a tooltip describing what you can do by dragging the manipulator. Drag the desired manipulator to translate, scale, or rotate the face.

    To turn off the Mini Move tool, deselect Mini Move tool in the Control Panel.
    Scale selected faces
    1. Press E to use the Scale mode of the Move tool.
    2. Scale the selected faces:
      • Drag the ring.
      • Click the ring, and then type a Scale factor.
    An alternative method for scaling: Position the cursor over the dotted line, which will change from green to yellow. The Scale/Inset face handle appears.

    When multiple faces are selected, you can transform all selected faces by clicking and dragging the graphic handle of just one selected face.

    Extrude selected faces
    1. Hover over a selected face until the yellow arrows and relevant tooltip appear.

    2. Do one of the following:
      • To extrude freely, drag the arrows.
      • To snap along the surface normal, while dragging the arrows, move the cursor close to the normal until the dotted blue line turns red.

        This is useful for extruding separate faces, each one along its respective surface normal (with standard extrusion, all faces would be extruded in the same direction).
      • To snap along the x-, y-, or z-axis, hold down Shift while dragging the arrows.
      Tip: To disable automatic rotation of the faces, hold down Ctrl while dragging the arrows.
    3. A microdialog is displayed showing the extrusion length. To define a precise extrusion length, enter the desired value and click Done.
     
    Inset selected faces
    1. Hover over a selected face. Position the cursor over the dotted blue line, which turn orange. The face also turns from orange to brown.

    2. Drag the Drag to create an inset handle.
     
    Show normals Right-click, and then select Show Normals.  
    Delete selected faces
    • Press Delete.
    • Right-click, and then select Delete Selected Faces.
     
    Extract selected faces Right-click, and then select Extract Selected Faces. Unlike the Face Extract tool used for NURBS surfaces, this Extract operation creates a completely new PolyNURBS object.
    Duplicate selected faces
    1. Right-click, and then select Duplicate Selected Faces.
    2. The Move tool will automatically be invoked, allowing you to translate the duplicate face to make it visible.
    This operation creates a completely new PolyNURBS object.
    Collapse selected faces Right-click, and then select Collapse Selected Faces.  
    Bridge selected faces
    1. To use this tool, the faces must belong to the same PolyNURBS object. You can select two single faces, or two sets of adjacent faces. If the faces belong to different objects, you must combine the separate objects into a single object first.
    2. Right-click, and then select Bridge.
    3. You have the following options:
      • Invert Direction: If bridging occurred in the wrong direction, use this button to correct it.
      • Rotate Forward: Shift the new faces one vertex forward.
      • Rotate Backward: Shift the new faces one vertex backward.
     
  6. Optional: Change how the faces are displayed.
    To Do this Note
    Hide the selected faces Right-click the PolyNURBS object, and then click Hide Selected.  
    Hide the unselected faces Right-click the PolyNURBS object, and then click Hide Unselected.  
    Show all faces Right-click the PolyNURBS object, and then click Show All.  
  7. Right-click and mouse through the check mark to exit, or double-right-click.

Advanced Selection Mode

Advanced selection mode is available when editing the edges or faces of a PolyNURBS object. It allows you to select multiple edges or faces.

Select Multiple Edges

  1. Double-click a PolyNURBS object.
  2. In the Control Panel under Edit, select Edges.
  3. Right-click the PolyNURBS object, and then select Advanced Selection on the context menu.
  4. You can do the following:
    To select/deselect Do this
    Edge Click the edge to select it. Click again to deselect it.
    Edge loop Hover over either end of an edge to display a yellow arrow. Click the arrow to select the loop in that direction. Click again to deselect the loop.
    Adjacent row Hover over the middle of an edge to display two yellow arrows. Shift-click the arrow that points to the adjacent row you want to select/deselect.
  5. To exit Advanced Selection mode, right-click the PolyNURBS object and deselect Advanced Selection.

Select Multiple Faces

  1. Double-click a PolyNURBS object.
  2. In the Control Panel under Edit, select Faces.
  3. Right-click the PolyNURBS object, and then select Advanced Selection on the context menu.
  4. You can do the following:
    To select/deselect Do this
    Face Hover over the center of a face. Click to select it. Click again to deselect.
    Loop of faces

    (A loop is a series of faces that starts and ends at the same face.)

    If a face has 4 edges (but no boundary edges), 4 arrows will be displayed to show the up, down, left, and right directions. Click on the arrow that points in the desired direction. Click again to deselect the loop.
    Adjacent row Hover over the arrow that points to the adjacent row you want to select. Shift-click the arrow to select the adjacent row. Shift-click again to deselect the adjacent row.
  5. To exit Advanced Selection mode, right-click the PolyNURBS object and deselect Advanced Selection.
    Note: You can convert a selection from one type to another, i.e., edges to faces, faces to vertices and so on. Select the desired edges and then go to vertices mode, the bounding vertices are selected. If you switch to faces mode, the faces within these vertices are selected.