LOD_Helper

• LOD Helper
  • General
  • Possible uses:
  • To create a LOD Helper in 3d Studio Max
  • Other options
  • Demonstration
  • More information

LOD Helper

General

LOD is an acronym for Level Of Detail. Typical uses are for load balancing - objects further away from the eye point are rendered at a lower level of detail. You can specify at which distance certain object will become visible or invisible.

Possible uses:

The usage as shown in the demonstration below is pretty stupid. Better uses are:

• Make the inside geometry of a house invisble when outside. This saves render time;
• Replace complex geometry with a simple textured box when far away. You'd have to create such an object in your scene as well. This saves (possibly a lot of) render time;

To create a LOD Helper in 3d Studio Max

• Create some geometry;
• Add a LOD Helper object;
• Specify the center of the LOD;
• Press the first None-button in LOD Obects, and assign an object to it;
• Specify the minimum and maximum boudaries. The object will be visible in between these. The distances are in Drawing units (and this should be set to metres to ensure proper dimensions in the Design Systems Viewer;
• Do this for all objects you wish to add to this LOD.

[Image:Osglodrollout.jpg]

Other options

1. LOD Center: This define the centerpoint of the LOD. Relative to this point all the distances will be calculated.
2. LOD Objects: You can specify for 5 objects the Min and Max distance. Between these two the object is visible, outside the boundaries it will not be visible.
3. Paged LOD: ...

Demonstration

[Image:Osgloddemo1.jpg] [Image:Osgloddemo2.jpg][Image:Osgloddemo3.jpg]
Here you can see that in the first picture only the box is visible. Zooming out the sphere appears as well. Even more zooming out makes the box dissappear. You can download the demofile[file:dsLOD.zip]. MAX-scene en OSG-export are included in the file.

More information

• OpenSceneGraph LOD class reference
• OSG Exporter HOWTO