Triangulation Settings

You can modify tolerances and construction parameters to affect curve sampling and scene triangulation. To modify these parameters, use the Triangulation Settings dialog box.

Positional Tolerance

The Positional Tolerance parameter controls the maximum deviation (in meters) between sampled polylines and their underlying analytical representation. As this value decreases, the number of samples and triangles produced increases.

Positional Tolerance: 0.005

Positional Tolerance: 0.01

Positional Tolerance: 0.1

Max Length

The Max Length parameter controls the maximum length between any two samples in the curve triangulation.

Max Length: 50.0

Max Length: 10.0

Max Length: 1.0

Height Field Sampling Parameters

Height Tolerance

The Height Tolerance parameter controls whether to include elevation samples in terrain triangulation (not roads) relative to the elevation of neighboring samples. Height tolerance is in meters. As the tolerance decreases, the difference between samples and the underlying elevation field with respect to elevation decreases. Typically, a low tolerance produces a large number of triangles.

Height Tolerance: 0.5

Height Tolerance: 0.05

Height Tolerance: 0.005

Height Min Spacing

The Height Min Spacing parameter controls the minimum distance (in meters) between samples and their neighbors. In general, the lower the tolerance, the closer the samples are allowed to be. Typically, a lower tolerance produces a greater number of triangles.

Height Min Spacing: 5.0

Height Min Spacing: 1.0

Height Min Spacing: 0.1

Height Max Spacing

The Height Max Spacing parameter controls the maximum distance (in meters) between samples and their neighbors. In general, the lower the tolerance, the closer the samples are required to be. Typically, a lower tolerance produces a greater number of triangles.

Height Max Spacing: 5.0

Height Max Spacing: 2.0

Height Max Spacing: 0.5

Road to Surface Blend Range

The Road to Surface Blend Range parameter controls the amount of distance (in meters) between the surface triangles and any adjacent edge.

Road to Surface Blend Range: 5.0

Road to Surface Blend Range: 1.0

Marking Projection

Every marking in RoadRunner is projected onto the underlying road or terrain surface to improve visual quality and avoid rendering issues such as z-fighting. The following pictures illustrate the result of projecting markings onto a complex road surface.

SLOW road marking stencil projected onto a road with an exaggerated height bump.

Outline of the original source marking stencil. The original flat stencil does not line up well with the underlying surface.

Marking triangulation that results after projecting the source marking outline onto the road surface.

Marking Construction Type

The Marking Construction Type parameter controls whether to stitch markings into the underlying road and terrain surface or to float the markings a small distance above the surface once they are projected. Floating markings (also known as decals) have the advantage of producing less triangles overall and allow for a more regular road surface triangulation. However, floating markings might require more handling once exported from RoadRunner to avoid z-fighting.

Markings produced with the Cut Out option enabled. The asphalt surface is triangulated around the marking.

Markings produced with the Floating option enabled. The asphalt surface triangulation passes beneath the marking geometry.

Floating Marking Offset

The Floating Marking Offset parameter controls how much to float a marking above the underlying surface. The lower the value, the smaller the gap between the markings and the surface, but the likelihood of rendering artifacts, such as z-fighting, increases.

Floating Marking Offset: 0.01

Floating Marking Offset: 0.5