Adjust import conversion settings

Overview

Conversion settings specify the tessellation and level of detail (LOD) to use to balance your viewing needs with system performance. Displaying small details uses up video memory. But larger scenes and models do not necessarily need small details displayed except when viewed in close proximity; the opposite is true for smaller scenes and models.

What is tessellation?

Tessellation is the process of subdividing a surface into smaller polygons (shapes) for rendering. The smaller the polygons, the more accurate the appearance, but the greater the impact on performance.

What are LODs and how do they affect surface quality?

Levels of Detail (LODs) are the different depths of tessellation that can be used for CAD (computer-aided design) models. Typically, LODs vary from low-fidelity (larger polygons, poor surface quality, and high rendering speed) to high-fidelity (smaller polygons, excellent surface quality, but may take time to render).

For example, the sphere in the following illustration is displayed, from left to right, with low- to high-fidelity LODs.

How do I change the LOD of an imported object?

Normally you should not need to change LOD settings for an object, unless you notice performance or display issues. For example, if rounded surfaces (such as wheels) do not have a smooth appearance, you may need to increase the surface quality and re-tessellate the file. In cases where performance is affected, Showcase will likely detect the problem and prompt you with the Import Status dialog box (described in the following procedure). You can change the LOD of objects manually anytime as follows:

Select the object.
Select File > Show Import Status.
In the Import Status dialog box, click Settings.
In the Change Conversion Settings dialog box, select a setting from the drop-down box. See the next section, Which LOD setting should I use?
The status of the APF file switches to “Needs update.” Click Convert to complete the re-tessellation.

Which LOD setting should I use?

There are six available settings in the Change Conversion Settings dialog box. (See the previous section, How do I change the LOD of an imported object?)

The first three are scripts that create a set of LODs for the model. These LODs are stored in memory and used by Showcase to optimize your view while you work. They are created on import or when you switch from one setting to another. The other three settings are single LODs that can be used if the scripts create too many polygons for your scene.

001-All-Purpose: this script is applied to objects by default (at import). It creates three different LODs in a wide range. Most objects will look good with this setting, though you may find it is preferable for exterior scenes with large objects, potentially with ground planes, where you might use moderate close-ups from time to time.
002-Large-Parts: this script creates three LODs optimized for larger parts. Small details will not render as well, but this script produces fewer polygons than the All-Purpose script, and therefore might result in better performance for medium and large objects.
003-Small-Details: this script creates three LODs optimized for smaller parts. More polygons are created, but this results in good quality for smaller (physically) sized scenes. It can also produce good results on moderate sized scenes that have many small details that are important to the user. Use this setting for small- to medium-sized models, like an ice skate or a dashboard; not recommended for large curved surfaces or shapes.
004-1LOD-Low: one LOD with a smaller number of polygons. Provides good performance for large models, with reduced quality in close-ups.
005-1LOD-Medium: one LOD with a moderate number of polygons. Good for medium-sized models.
006-1LOD-High: one LOD with a large number of polygons. Good for small models, but has a bigger impact on performance.

NoteYou must re-calculate ambient shadows if you change the tessellation.