Viewerhelp:Upload Model - Level of Detail

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Revision as of 11:54, 12 July 2011 by Jeremy Linden (talk | contribs)
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Select Level of Detail

You may click High, Medium, Low, or Lowest to preview and modify your model's various levels of detail.

Mesh

Load from file

You may manually upload your own models for each level of detail. This allows you to maintain tight control over how your model looks at each LOD, preserving key visual features that the automated algorithms may otherwise distort.

Auto generate

Generates a new model at the currently-previewed level of detail, based upon the model you uploaded.

Method

Choose a complexity level for your object, based upon a maximum number of triangles or a maximum amount of overall change in your model's shape:

  • Triangle limit: Enter the maximum number of triangles for the model at the selected level of detail. This number must not exceed the number of triangles in the LOD above it.
  • Error threshold: Increase this value to decrease the amount of detail retained during simplification. For example, setting this value to 0.1 results in a model that is simplified to 90% of the original model's accuracy.
Build Operator

Selects the method by which the number of vertices in your model is reduced.

  • Edge Collapse: Merges two vertices currently connected by an edge. Both vertices are replace by a new, unified vertex, which is chosen to minimize error. This method does a better job of retaining the model's original shape, but can distort textures and skin weights applied to the model.
  • Half Edge Collapse: Merges two vertices currently connected by an edge. One of the two vertices is merged into the other, which remains (essentially) unchanged. This method does a better job of keeping skin weights and textures properly aligned to the model, but may result in a slightly less accurate visual shape.
Queue Mode

Changes the order in which vertices are chosen to be merged.

  • Greedy: Recalculates the priority values for each neighboring edge after each simplification operation. This mode returns the best results, but requires the most computation and can take significant time on highly complex models.
  • Lazy: Marks the priority values of each neighboring edge as "dirty" after each simplification operation. Recomputation of costs is only done on required edges. This method is similar to Greedy, but is optimized to give much quicker and slightly less accurate results, making it useful for working with extremely complex models.
  • Independent: This method performs non-overlapping sets of operations on the input geometry, resulting in hierarchies of logarithmic height. It is about as fast as Lazy, but calculates its results differently.


Border Mode

Changes the handling of vertices on a geometric border; these are vertices without a full ring of triangles around them, like the edges of a flat plane.

  • Unlock: The default behavior, does not treat geometric border vertices specially.
  • Lock: Prevents any modification to or removal of border vertices. This is often useful when preserving the edges of models that are meant to align with each other, such as blocks of terrain.
Share Tolerance

This floating point parameter is intended to compensate for small floating point errors present in your data set. It controls the amount of distance between two vertices before they are considered coincident. Try increasing this number if cracks appear in your object during simplification.

None

You may choose not to include a model for any level of detail below High. The model will not appear in Second Life when rendered at a level of detail set to None. This setting may be useful for improving performance and decreasing resource cost for small, visually complex models that do not need to be viewed from far away.

Crease Angle

The Crease Angle adjusts the smoothness of the model. Increase this value to soften the hard, "faceted" look of models with relatively few vertices.