Mesh/Upload Model UI reference

Level 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 number of... errors???:

• 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: How does this work?

Build Operator

Selects the method used for incrementally reducing the geometry while building the multiresolution hierarchy. Need a higher-level explanation with less jargon. I think this means, "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.
• 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.

Under what circumstances is one of these better than the other?

Queue Mode

Changes the order in which vertices are chosen to be collapsed. (Does "collapsed" mean "merged", as above?).

• Greedy: Recalculates the priority values for each neighboring edge after each simplification operation.
• Lazy: Marks the priority values of each neighboring edge as "dirty" after each simplification operation. Recomputation of costs is only done on required edges. What does "dirty" mean?
• Independent: This method performs non-overlapping sets of operations on the input geometry, resulting in hierarchies of logarithmic height. Need a higher-level explanation with less jargon.

Why would I choose one of these over the others?

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 Is this example correct?.

• 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.

Physics

The physics decomposition step analyzes the model and generates a series of "hulls" that represent the physical shape of the model as it will be interpreted by Second Life's physics engine. Additional steps allow you to simplify the physics shape, thereby reducing the amount of load for the physics engine. Models meant to be used as vehicles must not have a physics cost higher than 32.

Step 1: Analysis

Method

Each of the three available decomposition methods is best suited to a particular type of shape, and will return the most accurate and least costly results when paired with a model of that type.

• Surface: Works best on curved, organic shapes, such as an animal body.
• Solid: Works best on objects with sharp angles and a clear inside and outside, like buildings.
• Wrap: Works best on very complex shapes, such as trees and branches.

Quality

These values determine how much combining and overlap reduction is performed on the hulls at the decomposition stage. High returns the best simplification results, but requires the most time to process. If you experience performance problems during this step, try using the Preview setting first in order to confirm your smoothing and Close Holes results, then switch to High to get the best simplification results.

Smooth

The Smooth value sets the tolerance when the utility tries to merge coplanar triangles. It refers to the angle between adjacent triangles for which merging is permitted. A value of zero allows some angle between triangles, resulting in gently curving surfaces being flattened.

A lower Smooth setting results in a lower physics cost for objects with curved surfaces.

Close Holes (slow)

Attempts to fill any holes in the physical representation of the model in order to fix minor errors in the mesh. However, checking this setting also closes intentional openings in objects and should not be used for models that are meant to be passed through, such as door frames.

Step 2: Simplification

Method

• Retain %: Select a percentage of the hulls to retain from the original analysis.
• Detail: Reduces the physics model to a single hull that resembles the basic shape of the model. Is this correct?
• Better Detail: Similar to Detail, but does a better job preserving openings in your model.

Passes

Increasing the number of passes creates results with fewer overlapping hulls and more accurate overall representation of your model's physical shape.

Detail Scale

Reducing this number preserves more fine detail in your model during the simplification process. Larger values result in a decreased physics cost, but lower accuracy in the physics model.

Preview Spread

Move the Preview Spread slider to explode your view of the hulls that comprise your physical model. On objects with many hulls, this can help you to find and examine hulls that would not otherwise be entirely visible.

Modifiers

Scale

Increases or decreases the base size of your model. Increasing the scale of a model can result in an increase in resource and upload costs.

Include

• Textures: Includes the model's textures in the upload, and automatically applies them to the model. Each texture increases the upload fee by L$10.
• Skin weight: Includes the model's skin weight information for the purposes of avatar rigging.
• Joint positions: Includes the model's joint positioning information for the purposes of avatar rigging.

Pelvis Z Offset

Changes the vertical offset of a rigged mesh when it is worn on your avatar. This parameter can be used to help properly align meshes that are not meant to be centered on an avatar's root location (pelvis).