Layers are like transparent overlays on which you organize and group different kinds of scene information. The objects you create have common properties including color, renderability, and display. An object can assume these properties from the layer on which you create it. Using layers makes it easier to manage the information in your scenes. Layers are used primarily to control the visibility of objects in your scene, however they also controls the color of objects' wireframe and the frozen and hidden state of objects, as well as their radiosity properties.
For example, you might want to set up a layer that will contain detailed, custom furniture. To do this, you create a layer and set Viewport Display to Bounding Box. Then you set the object's display properties to ByLayer (in the Object Properties dialog). This will keep the viewport display quick. Then, whenever you want to import new furniture, switch to this layer. You don't need to set up your viewport display every time you import new furniture. Also, if you don't want to render the furniture, you can turn off that layer's Renderable property.
Note: When you link an AutoCAD file into Autodesk VIZ, any layers that are frozen (and all objects that reside on these layers) are not imported.
Note: Objects can be hidden and frozen on a per-object basis; however, an object residing on a hidden or frozen layer will always adopt the hide/freeze state of its layer.
Tip: If you set lights' render control to ByLayer (in the General panel of the Preferences dialog), you can use the Render column in the Layer Manager to quickly turn lights on or off in your scene.
The Layer Manager displays layers, as well as their associated objects. This makes it very easy to organize, and make changes to objects in a scene. With the Layer Manager, you can adjust property settings at either the layer level, or individually for each object. Each property can be toggled between various states, including the ByLayer state. When an object’s property is set to ByLayer, the object inherits that setting from the layer it is associated with.
Note: The Hide and Freeze states of an object cannot be set to ByObject. Objects can be hidden or frozen on a per-object basis; however, they will always follow the behavior of their layer when it is hidden or frozen.
When you begin a new scene, Autodesk VIZ creates a special layer named 0 (default). By default, objects on layer 0 have their visibility settings on, renderability is on, and viewport display is set. You can’t delete or rename layer 0.
If you haven’t created any layers, Autodesk VIZ places objects you create on layer 0 by default. After you create objects, you can reassign them to different layers, including those residing on layer 0.
In the Layer Properties dialog, you can specify layer visibility individually for each viewport. If you don’t want to display a certain layer, you can hide that layer. Autodesk VIZ hides the layer in the viewport, but not in any output rendered image of the scene.
Note: For hidden geometry to render, Render Hidden Geometry must be turned on in the Render Scene dialog > Common Parameters rollout.
You can specify layers to display objects shaded, in wireframe mode, as a bounding box, or as whatever is set on the Viewport Properties menu. Using this method, you can have different objects displayed differently in the same scene.
You can display layers in See-Through mode. See-Through mode temporarily displays selected objects in translucent form so you can see through them without applying special materials. You can toggle See-Through mode for all objects per layer.
You can also Freeze, Hide, or Isolate the layer of a selected object using the corresponding command in the display quadrant of the quad menu.
You can create and name a layer for each conceptual grouping (such as walls or terrain) and assign common properties to those layers. By grouping objects into layers, you can control their display and make changes quickly and efficiently. When you name layers, you can use names of variable length up to 255 characters. These names can contain letters, digits, blank spaces, and the special characters dollar sign ($), hyphen (-), and underscore (_).
Note: Any layers from a linked AutoCAD file are automatically imported to Autodesk VIZ. Autodesk VIZ names the converted layers based on the layer names from the AutoCAD drawing.