task summary...
You can specify varying levels of detail for an object depending on the viewing distance; this increases performance by allowing fewer polygons to be drawn for an object that is far away. The Level of Detail Editor provides an interactive means for creating varying levels of detail and viewing the transitions in realtime. For more information, click the following topics: Level of Detail Editor or Polygon Reduction Editor.
The Level of Detail (LOD) Editor is a tool that allows you to
The mental model of the LOD Editor is similar to an animation flipbook. LOD's are pages (levels) ordered from closest (highest detail) to farthest (lowest detail). When you move away from the object, you flip through the levels as your distance increases. You can add and remove pages, or edit objects on a page. You cannot, however, add objects to an existing page.
Activate the LOD Editor by clicking on the LOD button on the menu bar, or by choosing "Level Of Detail Editor" from the Appearance menu. When you move the cursor over the LOD button the following message is displayed: Invoke Level Of Detail Editor
Note: The triangle count for the currently displayed object appears directly above the preview area in the LOD Editor.
For information on how to use the Level of Detail Editor, click a topic:
To import a file as a new level into the Level Of Detail Editor, follow these steps:
To paste the contents of the clipboard as a new level into the Level Of Detail Editor, follow these steps:
To duplicate a level of complexity of an object using the LOD Editor, follow these steps:
Some notes:
Some hints:
The following examples show the three levels of an object. Notice the difference in the triangle count between the first and third levels. The original triangle count is 1032; the third level triangle count is only 88.
To interactively set the transition distance of a level of an object, follow these steps:
Once you have created several levels and set the viewing distance of each level, you can flip through the levels and preview how the transitions will appear as someone moves through the scene. There are several key points to understand about the transition preview tool:
To automatically flip through the established level of a model to preview their transitions, follow these steps:
The portion of the window with the transition slider is shown in the illustration below.
The following examples show the previews of three levels of detail for an object.
Once you have created levels of detail for several objects within a scene, you may want to take an inventory of them before continuing with the scene construction. You can do this easily by choosing "Show LOD" from the View menu.
Note: This is an important tool for verifying that your transitions are taking place at reasonable distances. Using Show LOD helps you quickly identify objects which LOD transitions do not happen at appropriate distances. You may also find that objects close to each other are transitioning between levels at very different distances. You may wish to make those transitions more equal.
The level of the LOD for each object is displayed according to the viewing distance from the camera. Objects that have LODs are rendered in a color depending on the level, or distance at which they are displayed. The color coding for levels is as follows:
Red:
first level; closest to the camera
Gold:
second level
Yellow:
third level
Green:
fourth level
Light
Blue: fifth level
Dark
Blue: sixth level
Purple:
seventh level; furthest away from the camera
Eighth level: color cycle repeats
The colors cycle back to red after purple. This means that an object that is very, very far away could be red, as well as an object that is up close. There would have to be eight levels to the object for this to happen, however.
The following illustration shows a scene with chess pieces having different LODs. The closest chess piece appears red, the gold piece is next closest, and the yellow pieces are furthest away.