7

Working with Layers

Layers provide a way to organize your model and improve your workflow by dividing the model into big separable chunks.

In this Section:

• Layers Menu Summary 234
• Introduction to Layers 235
• The Layer Stats Window 246
• The Layers Bar 251
• Creating New Layers 255
• Selecting Layers 257
• Setting the Layer State 259
• Deleting Layers 260
• Changing the Visibility of Layers 261
• Setting Symmetry on Layers 263
• Setting Animation Playback 267
• Setting the Creation Layer 268
• Assigning Objects to Layers 269
• Enabling and Disabling Layers 270
• Toggling between Layer Names and Numbers 271

Layers Menu Summary

Most layers tools are located in the Layers menu, as described in the table below. See also The Layer Stats Window on page 246.

Layers >	For information...
New	Creating New Layers on page 255
Select	Selecting Layers on page 257
Set State	Setting the Layer State on page 259
Delete	Deleting Layers on page 260
Visibility	Changing the Visibility of Layers on page 261
Symmetry	Setting Symmetry on Layers on page 263
Playback	Setting Animation Playback on page 267
Set creation layer	Setting the Creation Layer on page 268
Assign to layer	Assigning Objects to Layers on page 269
Undo assign
Tgl layers	The Layers Bar on page 251 as well as Enabling and Disabling Layers on page 270
Tgl Layers Bar
Tgl Name/Number	Toggling between Layer Names and Numbers on page 271

Introduction to Layers

Layers provide a way to organize your model and improve your workflow, by dividing the model into big separable chunks.

Layers provide various attributes, such as visibility and restricted pickability, that help in applying that attribute to all the objects in that layer. Layers can be named interactively by entering a name or number.

What is a Layer?

For information on stages, see Using Stages on page 404.

A layer is an association or a collection of objects independent of any group hierarchy in your model, with an independent set of attributes. Each stage in Alias has a different set of layers.

Layers let you manage complex models by organizing various objects into more easily manageable chunks. This model management improves your workflow and performance by:

• drawing only working parts of the model

• restricting the picking to the working part of the model

• assigning the layers different colors, to increase the visibility of parts of the model

• quickly finding a necessary part of a complex model

• selecting and modifying significant model features more easily.

Notes:

• Layer colors apply to inactive objects only.

• Layer attributes override object attributes.

• You can temporarily turn off layers without losing the layers and their attributes.

• The additional functionality of layers means you will have to plan ahead to create well-organized layers.

Layers Bar

For more information on the layers bar, see The Layers Bar on page 251.

The layers bar is located below the prompt line at the top of the Alias window. It contains a list of all existing layers.

The layers bar always contains at least one layer, named DefaultLayer. Clicking on the layer name displays a menu from which you can set different attributes for this layer, assign an active object to the layer or pick the objects belonging to the layer.

Layer Attributes

Use the following attributes to organize your model.

Pickable layers

Objects on a layer are pickable by default. You can change this attribute on any layer except the default layer (which is always pickable and visible).

Reference layers

Objects on these layers cannot be picked, but you can snap to them. They allow curve snapping to all the objects in that layer. CVs and edit points are not displayed on reference layers.

Inactive layers

You cannot pick or snap to the objects or nodes on the inactive layers. They may appear similar to templated objects, but they are displayed in a different color. You cannot pick them using Pick > Template.

See Editing the Colors in Layers on page 244.

Colors

You can assign any inactive modeling color to a pickable layer in the layers bar (except the Default Layer). The default inactive layer color is blue, and the reference layer color is brown. If the color is none, the objects appear in their respective default modeling colors.

To set the color for a layer, click the square beside the layer name in the layers bar and select one of fifteen colors.

Click the Edit button to open the Color Editor and edit the color of your layer.

The None button means that the layer does not have a color and default Alias colors are applied to that layer.

Visible

Objects on layers that are not visible are not displayed and cannot be picked in the modeling, SBD or ASBD windows.

See Setting Animation Playback on page 267 for more information.

Playback

If you have several characters in a scene and want to look at each character's animation separately, you can place each character in its own layer and play back the animation of each character as you wish.

Name

You can assign a name to each layer, which helps to create meaningful layers for a model. To change the layer name, double-click the layer's button in the layers bar, type the new name and press Enter. By default, the layer name is a layer number prefixed by letter L. For example, the default name of the layer numbered 57 would be L57.

Number

Each layer has a unique layer number in addition to the layer name. The layer number can not be modified. Since the layers have both a name and a number associated with them, you have the choice to view the layers by their name or their number.

Layer name or number

You can select your layers either by their name or their number. In the name mode (set by default), all the layers display their name in various places in the interface. While in the number mode, only the layer numbers are displayed. A function exists to toggle between the name and the number mode (see Toggling between Layer Names and Numbers on page 271).

How Attributes are applied

Attributes are applied in the following set hierarchy:

• Alias color

• User assigned color

• Template

• Layer pickability

• Visibility

Attributes Associated with Layer States

In the following table, a check mark indicates if the attribute in the left column can be assigned or used in conjunction with the given layer (layer types are discussed later in this section). An "X " means the attribute cannot be used with the layer.

	Default Layer	Creation Layer	Pickable Layer	Reference Layer	Inactive Layer
Snap to objects	4	4	4	4	6
Pick objects	4	4	4	6	6
Pick templates	4	4	4	6	6
Pick in SBD and ASBD windows	4	4	4	4	4
User color	6	if assigned	if assigned	6	6
Construction history color	4	4 user color if assigned	4 user color if assigned	6 reference layer color	6 inactive layer color
Lights used	4	4	4	6	6
Render/Qk render/Tgl Shade/Diagnostic Shading	4	4	4	6	6
Plotting	4	4	4	6	6

Viewing Layers in the SBD and ASBD Windows

In the SBD window, a small box in the lower right corner of the node shows the layer assignment of the node. Nodes in the default layer do not have a box. The color of this box is the same as the object in the modeling windows. The name or number of the layer also appears in this box. An invisible layer appears as a box with a dotted outline.

The following example shows the SBD window's layer representation.

The ASBD window displays layer information in the same way. However, by placing the cursor over a node, you can also see the node name and its layer name on the prompt line of the ASBD window.

Default Layer

One layer with fixed attributes is always present when layers are toggled on. This is the default layer, and is initially the creation layer, so new objects will always appear in it. The default layer always has the number 0 and its name and attributes cannot be modified.

Creation Layer

You can make any layer (including the default) the creation layer by clicking the layer's button in the layers bar or by selecting Layers > Set creation layer. Whenever you create a new layer, that layer automatically becomes the creation layer. The creation layer's button appears in yellow.

Layer assignment

See The Layers Bar on page 251 for more information on assigning layers.

Any picked DAG node or object can be assigned to a layer. When you assign a node to a layer, the following rules apply:

• all the nodes beneath the picked node are automatically assigned to the same layer.

• all the parent nodes automatically go into the default layer.

• all the sibling nodes are unaffected.

All new nodes are automatically assigned to the current Creation layer. While grouping and duplicating the layered DAG nodes, the layer assignments of the original nodes remain the same. The layer assignment can be easily changed at any time.

Finding a node's layer assignment

Any node's assigned layer can be found in:

• Windows > Information > Information window

• Object Edit > Query edit window

• SBD window

• ASBD window

In addition, the user colors help in differentiating nodes belonging to different layers.

Selecting Multiple Layers

See also Layer Categories on page 249.

Sometimes you may want to set the attributes for multiple layers. Press the Shift key and click on the layers' buttons in the layers bar to simultaneously select layers. Once you select the desired layers, their attributes can be set collectively in the Layers menu.

Saving and Retrieving Layers

The following describes the methods that you use to save and retrieve your layers.

Retrieving Layers

For information on File > Open, see Opening Files on page 84 .

Your retrieve layers as though they were files. To retrieve a layer, select File > Open - and make sure Keep Layers is set to ON in the Open File Options window.

Click the Open File button at the bottom of the Open File Options window and select the file you want from the file list, or type its name in the File Browser.

All the layers are retrieved, along with the layer assignment of the objects. If a layer with the same name as one in the retrieved file already exists in the current stage, the retrieved layer is merged with the existing one.

If you set Keep Layers to OFF, all the DAG nodes in the retrieved file are automatically loaded into the creation layer, and the layers stored in the retrieved file are ignored. Similarly, older versions (previous to Version 8.0) are also retrieved into the creation layer.

If you import one file into another and they have more than 255 different layers between them, then all the objects on the extra layers of the imported file are put into the default layer.

This is summarized in the table below.

Layer Behavior with files

Where objects go in the layer structure	Open / Import				Merge Stages
	pre Version 8 file		Version 8 file and later
	Keep layers ON	Keep layers OFF	Keep layers ON	Keep layers OFF
New or matched layers			4		4
Default Layer	4		layers over 255		l ayers over 255
Creation Layer		4		4

Saving Layers

The layers are automatically saved in the wire file.

Pick Objects Option

When you select Pick Objects from a layer's pull-down menu, the root node of the hierarchy is selected, as shown in the following SBD view.

The highest node in the hierarchy (not necessarily the root node) is picked so that it is not above a node on an unpickable layer.

Layers and Stages

Stages are completely independent of each other, so the layers in each stage are totally separate. You can create up to 255 layers in a single stage, and reference the layers with a layer name. Each stage can have its own set of layers.

Layer workflow examples

To transfer all the objects from one layer to another:

1

Select Pick Objects from a layer's pull-down menu to pick all the objects from the source layer.

2

Select Assign from the pull-down menu of the destination layer.

To turn on the bounding box for a layer:

1

Select Pick Objects from a layer's pull-down menu to pick all the objects from the source layer.

2

Select Object Display > Bounding box from the menu bar to turn the bounding box on for the layer.

This workflow applies to a whole range of functions. For example, saving a layer's contents to a wire file (with File > Export > Active as), or turning the simple display ON. In fact, with this mechanism, any function used for picked objects can also be applied to the layer.

Editing the Colors in Layers

You can change any one of the fifteen layer colors by following the steps below. These colors correspond to the default inactive modeling colors found in the User Colors window.

1

Click the color square on any layer button, and select Edit from the Color Palette. This brings up the User Colors window and opens the Inactive Modeling Colors section.

2

Click on one of the color tabs (rectangles with white arrow) that corresponds to the color you want to change. This opens the Color Editor window.

3

In the Color Editor window, replace the current color by the color of your choice by clicking on a color palette or entering the R,G,B values in the editable fields. This will also modify the color of one or more modeling entities (for example if you replace the brown color, both the Hull and Edit Point color are affected).

4

If you want, you can set the color of these modeling entities to a different inactive color by using the individual color sliders in the User Colors window.