For a node that is, or includes, an IndexedFaceSet node, you can improve rendering speed by reducing the number of polygons in the IndexedFaceSet. Choose the polygon reduction factor that produces your desired balance of rendering performance and quality.
To reduce the number of polygons:
Right-click an IndexedFaceSet node, or a node that includes one or more IndexedFaceSet nodes.
Select Optimize Child Geometries.
In the Geometries Optimization Preview dialog box, use the slider or enter a value in the Polygon reduction factor field to set the polygon reduction factor. A value of 0 performs the maximum reduction, and a value of 1 performs no reduction.