X3D Example Archives: Conformance Nist, Special Groups, LOD

 

LOD (Level Of Detail) uses camera-to-object distance to switch among contained child levels. (Contained nodes are now called 'children' rather than 'level', for consistent naming among all GroupingNodeType nodes.) LOD range values go from near to far (as child geometry gets simpler for better performance). For n range values, you must have n+1 children levels! Only currently selected children level is rendered, but all levels continue to send/receive events.

X3D Tooltips of interest: LOD.

X3D Specification sections of interest: 23 Navigation component, 23.2 Concepts and 23.4.3 LOD.

X3D Examples Archives of related interest:

 
  10 X3D Models       X3D Model Descriptions
   bound_500 bound 500 This tests checks the boundary condition of 500 children per grouping node. An LOD node is defined with 500 children in its "level" field. Section 7.3 (Minimum Support Requirements) of the VRML specifications 500 children within a single grouping node. The test is started by clicking on the text below the figure. The test should generate a figure that resembles a temple with white columns, a fly of stairs up front and a
   empty_range empty range Test browser to use its own algorithm when and empty range list is specified in the "range" field. The test "ref4.x3d". The range field specifies an empty list which indicates to the browser to use its own algoritmh to compute the proper distance to display the versions of the figure. Each of the two entries in the level field adds a level of detail to the figure in question as the users avatar gets closer to the figure. The distance of the viewer from the object is changed by clicking on the desired buttom as indicated by the text displayed. The test should generate a figure that resembles a temple with logo mapped to it (this is the figure that is displayed when the highest level of detail is selected. Other levels display a version of the same figure, but with much less details.)
   extra_levels extra levels Test browser to ignore extra entries in the level field for which there are no corresponding entries in the range field. The test defines an LOD node with the level field ref2.x3d,ref3.x3d,ref4.x3d. The range field specifies two different range values that indicate at what distance to display the corresponding entry from the level field. The fourth entry in the level field does not contain a corresponding entry in the range field and therefore should always be ignore regardless of the users avatar position Each entry in the level field adds a level of detail to the figure in question as the users avatar gets closer to the figure. The distance of the viewer from the object is changed by clicking on the desired buttom as indicated by the text displayed. The test should generate a figure that resembles a temple with white columns, a fly of stairs up front and a displayed when the highest level of detail is selected. Other levels display a version of the same figure, but with much less details.)
   few_levels few levels Test browser to associate extra entries in the range field with the last entry in the levels field. The test specifies four different range values that indicate at what distance to display the corresponding entry from the level field. The second, third and fourth entries in the range field does not contain a corresponding entry in the level field and therefore should always be associated with the entry named ref2.x3d in the level field regardless of the users avatar location. Each of the two entries in the level field adds a level of detail to the figure in question as the users avatar gets closer to the figure. The distance of the viewer from the object is changed by clicking on the desired buttom as indicated by the text displayed. The test should generate a figure that resembles a temple with white columns, a (this is the figure that is displayed when the highest level of detail is selected. Other levels display a version of the same figure, but with much less details.)
   multiple_level multiple level Test browser to associate multiple entries in the level field with corresponding entries in the range field. The range field specifies three different range values that indicate at what distance to display the corresponding entry from the level field. Each entry in the level field adds a level of detail to the figure as the users avatar gets closer to the figure in question. The distance of the viewer from the object is changed by clicking on the desired buttom as indicated by the text displayed. The test should generate a figure that resembles a temple with white columns, a fly of stairs up front and a displayed when the highest level of detail is selected. Other levels display a version of the same figure, but with much less details.)
   ref1 ref 1 This is a collateral file used in other tests of this node.
   ref2 ref 2 This is a collateral file used in other tests of this node.
   ref3 ref 3 This is a collateral file used in other tests of this node.
   ref4 ref 4 This is a collateral file used in other tests of this node.
   test_center test center Test browser to set different values for the "center" field. The test defines two LOD node with the level field via the Inline node). The first LOD defines the leftmost figure and it sets the center to location 0 0 0. The second LOD defines the rightmost figure and it defines the center at location 0 0 40. The left most LOD in the level field. The rightmost LOD should only display the figures various options at the bottom of the figures. The test should generate a figure resembling a temple with white columns, a fly of stairs up front generated when the highest level of detail is selected), however the LOD to the right will display this figure for the TWO highest level of details

The X3D Resources: Examples page and Savage Developers Guide provide more information about the production of this archive.