Snap to curves, points, or the grid

The snap modes “snap” or lock movement/placement of objects and points.

Snap to...	Hold	Or click
Curves, isoparametric curves, surface edges, or curves-on-surface. When the appropriate options are turned on, can snap to curve divisions, pivot points, or bounding box center, as well as curve intersections (true or projected).Also snaps to construction planes (see below).	+
Grid intersections.
CVs, edit points, pivot points, locators.

Curve Snap Options

Click on the small arrow to the right of the icon to open a window with the following options.

Snap Divisions

You can use arc length snapping on curves (snap to the midpoint, 1/3, 1/4, etc) by setting Snap Divisions to a value from 0 to 100. For example, setting this value to 2 and then using snap gives you a “snappable” point (shown as a light blue line segment) halfway along the curve.

Snap to Center

When this option is turned on and you click on a curve, the center of the curve’s bounding box is displayed as a small cross surrounded by a circle. Moving the cursor in close proximity of the center icon lets you snap to it.

Pivot

When this option is turned on and you click on a curve, its pivot is displayed. Moving the cursor in close proximity of the pivot icon lets you snap to it.

You can snap to both the scaling and rotation pivots (if they are not in the same location).

Projected Intersections

When this option is turned on, you can snap to the intersection points between curves in any orthographic or perspective view, even if the curves don’t truly intersect in world space. These intersection points are displayed as pink crosses.

NoteIf the model contains a lot of geometry, snapping to projected intersections may take a few seconds to occur.

True Intersections

If this option is turned on, then:

• snap will automatically snap to all intersections between free curves, surface edges, isoparms, curves on surface, and trim edges.
• snap will automatically snap a new curve-on-surface (CoS) to CoS-CoS intersections on the same surface.

More features of Curve Snap curve

• snap automatically snaps to the locations where the curve intersects a plane. The intersection points are shown as purple crosses.
• If you click on the edge of a construction plane while curve snap is on, movement is constrained to that construction plane.
• After snapping to a curve using Ctrl + Alt, you can release the keys and movement will remain constrained to the curve.
  TipWhen using curve snapping, you can release the hotkeys after the item has snapped to the curve, and the item will continue to stick to the curve as long as the mouse button is pressed.

Horizontal and vertical snapping

In orthographic windows, you can snap to the horizontal or vertical level of the thing you click, instead of its exact position:

• Click the to snap to the horizontal position.
• Click the to snap to the vertical position.

For example, you can line up three CVs along the same horizontal line without affecting their vertical positions:

1. Use Pick > Point types > CV to pick the CVs.

   

2. Choose Transform > Move.
3. Hold to turn on magnet snapping.
4. -click the CV you want to align with.

   

The picked CVs move to snap to the vertical position of the CV you clicked, but keep their own horizontal position.

View and edit the construction history of an object

How to edit an existing object by altering the history of how it was created.

Construction history allows you to do two things:

• Edit the tool options used to create an object.
• Update an object by modifying the objects used to create it (for example, the construction curves you used to create a surface).

Editing construction history automatically updates the object.

Construction history

Open the History View

• Choose Windows > Information > History view.

  or

  Click the history button to the right of the prompt line.

  

Sort the objects by the tool used to create them

• To group objects created by the same tool together, open the history window’s List menu and choose Sort By Type.
• To list objects normally (roughly in the order you created them), turn off Sort By Type.

View how an object was created

1. In the History View window’s List menu, choose Active.
2. Pick the object.
3. Click the arrow next to the name of the object.

   

   The list shows the operation’s constructors and target (result).

   TipPress and hold the on the name of an object in the History View window to highlight the object in the modeling windows.

Change the tool options used to create an object

• In the History View window, click the icon next to the name of the object.

  

Edit tool option history by clicking an object

1. Choose Object edit > Query edit.
2. Click the object.

   If the object has editable history, the Query edit tool will automatically select the appropriate tool for editing.

What if...?

Construction history updates are slowing down my work?

You can temporarily suspend construction history updates to improve performance. See the section, Suspend and resume construction history updates, that follows.

My curve or surface does not change when I edit its history?

• AliasStudio allows you to suspend construction history updates temporarily. If construction history is suspended, the construction history button’s H will have a line through it.

  To turn updates back on, press the construction history button and turn off Suspend Rebuilds.

  Suspend and resume construction history updates

• AliasStudio allows you to turn off construction history updates during certain actions to speed up the display. If updates are turned off, you may not see an object change when you edit its history.

  To turn updates on, choose Preferences > Performance options and turn on the options in the Construction History Updates section.

Suspend and resume construction history updates

How to temporarily suspend updates of construction history to improve performance.

Suspend all construction history updates

• In the history window, open the Rebuild menu and choose Global Suspend.

  or

• Press the history button to the right of the prompt line and turn on Suspend Rebuilds in the pop-up menu.

  

  TipIf construction history is suspended, the construction history button’s H will have a line through it.

Resume construction history updates

• In the history window, open the Rebuild menu and choose Resume.

  or

• Press the history button to the right of the prompt line and turn off Suspend Rebuilds in the pop-up menu.

  

Control interactive construction history updates

• Choose Preferences > Performance options and set the options in the Construction History Updates section.

Delete construction history

Breaks the links between the picked object and any objects that you used to create it.

Delete construction history from an object

1. Pick the object from which you want to delete construction history.
2. Choose Delete > Delete construction history.

What if...?

I only want to turn off construction history temporarily to improve performance?

You can temporarily suspend construction history updates and then resume them when you want to update the display. See the section, Suspend and resume construction history updates, for more information.

Suspend and resume construction history updates

Use objects as templates

Templating is a very useful way of getting objects “out of the way” (so you don’t accidentally pick or modify them), but still have them visible.

Template an object

1. Pick the objects you want to template.
2. Choose ObjectDisplay > Template.

“Untemplate” an object (return a templated object to normal)

1. Choose Pick > Template.
2. Pick the templated objects you want to untemplate.
3. Choose ObjectDisplay > Template.

Create a reference point

Use the Point tool to create a general- purpose reference point at a location in space or on any type of geometry.

Create a reference point

1. Choose Construction > Point.
2. Click to create the point, or type the coordinates for the new point.
3. Use the mouse and keyboard in tools.

Create or edit a reference vector

Use the Vector tool to create a general-purpose reference vector at a location in space or on any type of geometry. You can use this vector as input to tools that require a direction.

Create a reference vector

1. Choose Construction > Vector.
2. Click to place the origin of the reference vector, or type the coordinates.

   Use the mouse and keyboard in tools

3. Set the direction of the reference vector.
   TipIf you constrained the vector origin to a curve or surface, you can click XYZ/GEOM to switch the manipulator orientation between global (XYZ) and geometry parameter space (GEOM).
4. Click Set Vector.

Edit a reference vector

1. Choose Construction > Vector.
2. Click the origin or end point of the vector to edit them.
3. Click Next Vector.

Create a reference vector from a perspective view

1. Choose Utilities > Plug-in Manager.
2. Load the createPerspCameraVector plug-in.
3. Choose Construction > Create Persp Camera Vector.
4. Click in the perspective view to create the vector.
   NoteBecause the vector is perpendicular to the view, you may need to tumble the view to see the vector.

Create or edit a reference plane

Use the Plane tool to create a reference plane which you can use as input to tools requiring a plane, or as the construction plane.

Create a reference plane

1. Choose Construction > Plane.

   Five buttons appear at the bottom of the view window. Each allows you to create a different type of construction plane. The five types are:

   View

   This is a 1-point construction plane where you specify the center point of the plane. The plane is oriented so that the Z-axis is parallel to the view vector. You can also snap the point to any geometry.

   Slice

   This is a new type of plane where you specify 2 points. The third point is placed at the eye position so that you are looking at the plane from the edge. This type of plane is useful for defining cross sections.

   3 Pt

   This is the regular 3-point construction plane where you completely define the plane by inputting three points.

   Geom

   This lets you snap the center point of the plane to geometry so that the Z-axis is oriented along the surface normal or curve tangent.

   World

   This is also a 1-point plane. You specify the center point and the three axes are oriented along the world axes. You can snap the point to any geometry.

   NoteView, Geom and World planes have manipulators that you can use to tweak the orientation of the plane.

2. Click on the button for the type of plane you want to create.
3. Click to place one, two, or three points, according to the instructions on the prompt line. You can also type the 3D coordinates for a point.
4. Adjust the plane by moving the point(s), or using the manipulator (if available), to move, rotate, and size the plane.
5. To make this plane a reference plane, and go on to create another plane, click Next Plane.

   To make this plane the construction plane, click Set Construction Plane.

   NoteThere can only be one construction plane in a scene. If you create a construction plane and there is already a construction plane in the scene, the existing construction plane will become a reference plane.

How do I use the plane manipulator?

Drag a handle to move, scale, or rotate.

Click a handle to select it and then type exact values, or snap to another point to orient the handle.

See To use the plane manipulator for more details.

Edit a reference plane

1. Pick the plane.
2. Choose Construction > Plane.

   The points and manipulator (if applicable to this type of plane) appear.

   NoteYou can also select the Plane tool first, then select the plane you want to edit.
3. Adjust the plane by dragging the point(s), or using the manipulator.
   TipOpen the Information window (Windows > Information > Information window) to see detailed information as you manipulate the plane.
4. To make the plane a reference plane and go on to create another plane, click Next Plane.

   To make this plane the construction plane, click Set Construction Plane.

   NoteThere can only be one construction plane in a scene. If you create a construction plane and there is already a construction plane in the scene, the existing construction plane will become a reference plane.

Work with the construction plane

How to switch between the world coordinate space and the coordinate space of a reference plane.

Switch between worldspace and the construction plane

• Click Construction > Toggle Construction Plane.

Make a reference plane the construction plane.

1. Pick the reference plane.
2. Click Construction > Set Construction Plane.

Move mouse buttons and construction planes

You can choose between the following mouse behaviors when using Transform > Move in a perspective window with an active construction plane:

• Three dimensional:
  • the moves along plane’s X
  • the moves along plane’s Y
  • the moves along plane’s Z

or

• Planar:
  • the moves freely across plane’s X and Y
  • the moves along plane’s X
  • the moves along plane’s Y

To change between the two control schemes:

1. Choose Preferences > General Preferences r.
2. Choose Input on the left side of the option window.
3. Set the Mouse mapping for perspective move : On construction plane option.

Automatically create symmetrical geometry

How to set a layer to automatically show the symmetrical half as you create one half of a model.

Almost every real-world model displays some form of symmetry. It is efficient to create half of the model, then reflect it to create the other half. Symmetry planes automate this process, by updating the symmetrical half as you model.

Set the plane across which the model will be mirrored

1. Click the layer(s) for which you want to set the symmetry plane.
2. Choose Layers > Symmetry > Set plane.
3. Use the plane manipulator to set the symmetry plane:
4. Click Set Plane.

How do I use the plane manipulator?

• To quickly snap the manipulator to the end of a curve, click the center move handle, then use curve snapping to snap the manipulator to the curve.
• Drag a handle to move or rotate.
• Click an arrow to change the center handle to the free move handle. Then drag the center handle to move the plane.
• Click a sphere to change the center handle to the free rotate handle. Then drag the center handle to rotate the plane.

Show or hide mirrored geometry

1. Click the name of a layer that has a symmetry plane set.

   A white outline appears around the name of the layer.

2. Do one of the following:
   • Choose Layers > Symmetry > On to show the mirrored half for this layer.
   • Choose Layers > Symmetry > Off to hide the mirrored half for this layer.

Convert a mirrored half into real geometry

1. Select the layer or layers on which you want to convert the mirrored geometry.
2. Choose Layers > Symmetry > Create geometry.
   NoteThe mirrored geometry becomes new geometry and is no longer affected by changes to the other half.
   TipThe geometry on the layer or layers is still being mirrored. To improve performance, turn symmetry off in the Layers menu.

What if...?

I want to align an object tangent with its symmetrical half?

Align curves or surfaces across the symmetry plane

View or change the properties of objects and locators

Use the Information Window to view and edit information about the picked object(s).

View and edit object properties

• Choose Windows > Information > Information window.

  

  The Information window always displays the information for the picked objects.

  TipWhen more than one object is picked, the different objects are displayed under collapsible headings with their names.

Show basic information about an object

1. Choose Object edit > Query edit.
2. Press the on an object.

   The Query edit tool also shows construction history dependencies graphically:

   • The object you clicked is drawn in yellow.
   • Curves and surfaces used to construct the object are drawn in green.
   • Curves and surfaces built from the object are drawn in blue.
   • Multi-knots are highlighted with a red arrow.

Edit information about an object

1. Choose Windows > Information > Information window.
2. The information window opens, showing information about the picked objects:

   

   Checkboxes can be set and unset to change the visualization of data. Information in white cells can be edited.

What if...?

I want to keep information about an object visible in the information window even when the object isn’t picked?

Pick the object, then click the icon next to the name of the object.

The object will be shown in the information window whether or not it is picked. To get rid of the information, click the icon again.

Use selection handles to make picking easier

You can create selection handles to represent an object or group of objects. Picking the selection handle picks the objects it represents.

If you are constantly working on separate objects that share a confined space, or objects inside groups, or deeply nested groups, picking and unpicking the objects can become tedious.

Selection handles can help you solve these kinds of problems.

• When picked, the selection handle picks the object or group it was assigned to when it was created.
• A selection handle is labeled with the name of the object or group it picks, so you can tell them apart.
• You can move a selection handle anywhere it the scene, away from the object or group it picks.

Create a selection handle

1. Pick the object or group the selection handle will pick.

   If you pick more than one object or group, AliasStudio will create separate selection handles for each.

2. Use the control panel or the information window to give the object or group a meaningful name.

   The selection handle will be labeled with the name of the object or group it picks. To make it easier to remember what the selection handle picks, give the object or group a descriptive name before you create the selection handle.

   See the section, View or change the properties of objects and locators, for more information.

3. Choose Animation > Create > New selection handle.

Move a selection handle

1. Pick the selection handle (using Animation > Pick > Selection handle) or its target object.
2. Choose Animation > Tools > Move selection handle.
3. Use the mouse or keyboard to move the handle.