Overview

When importing models, you need to decide the optimum conversion settings to balance your viewing needs with the expense of waiting for the model files to be converted to APF format.

When you are importing model files, you can choose from a list of default conversion scripts from the Convert Imported Models window:

This list of tessellation scripts optimize for:

• Large (“Default”) or “Small” objects. Use the default scripts for large objects such as cars, the “Small” scripts for small objects such as phones. The “Small” scripts tessellate at a finer level, and if used on large objects would create models that are too heavy.
• The number of levels of detail (“1LOD”, “2LOD” and so on). See below for a definition.
• Levels of surface quality (low, medium, high and so on)
• No tessellation (use this script if your model is already tessellated)
• No shelling (“Not Merged”). These scripts do not run the autostitch script that stitches and shells together the surfaces of the model. In this case, you need to stitch together and shell these surfaces in their original modeling program. (Otherwise, the surfaces won’t show continuous textures.)

What are LODs and how do they affect surface quality?

Model surfaces are too complex to render interactively, so a simplified polygonal mesh geometry is required to present them on the screen.

Levels of Detail (LODs) are the number of different polygonal surface representations that exist for a particular model. Typically LODs vary from low-fidelity (meaning the surface quality is poor but the rendering speed is high) to medium-fidelity to high-fidelity (meaning the surfaces look very good, but may take time to render).

The number and types of display quality available to you is directly related to the number of LODs that exist in an imported file. Select Options > Performance and Quality (Ctrl+L) to balance off display quality with smoothness of motion when you navigate around objects.

You can choose to create various LODs, each with different surface quality characteristics. To speed up the time to calculate tessellation, you can choose to convert files to only one LOD at a particular surface quality. If there is only one LOD, you will not be able to trade off on surface quality and speed using the Performance and Quality window.

To verify the number of levels of detail (LOD) after you load a model, select Options > Performance and Quality, click the Lock display quality to button, and move the slider back and forth to see the different LODs.