DistanceFieldTraceSettings

Remarks

StepScale below one is not timidity, it is correctness. Sphere tracing is exact when the field is exact: a step of d can never cross a surface that is d away. A sampled field is not exact — a trilinear interpolation over-reports near a convex corner, which is precisely a step that crosses the surface and a ray that comes out the other side. Scaling the step back down is what buys that margin, and it is why the number lives here rather than being hard-coded at nine-tenths and forgotten.

SurfaceThreshold should be a fraction of the field's cell: much smaller and the march creeps toward a surface it cannot resolve anyway; much larger and it stops short, which reads as everything being slightly inflated.

Fields and properties (6)

• public float MaxDistance

  How far along the ray to look.

• public int MaxSteps

  How many samples the march may take before giving up.

• public float SurfaceThreshold

  How near counts as arrived.

• public float StepScale

  What fraction of the reported distance each step actually takes.

• public float MinStep

  The shortest step worth taking, so a march grazing a surface cannot stall.

• public float StartDistance

  Where along the ray to begin.

Methods (2)

• public DistanceFieldTraceSettings()

  The defaults: a hundred units, a hundred and twenty-eight steps, nine-tenths of a step.

• public void Validate()

  Throws if these settings cannot march.

Used by (10)

• CardRadiosityVixen.Rendering.SurfaceCache
• CornellBoxTestsVixen.Rendering.SurfaceCache.Tests
• DistanceFieldTracerVixen.Rendering.DistanceFields
• DistanceFieldTracerTestsVixen.Rendering.DistanceFields.Tests
• ExitCriteriaTestsVixen.Rendering.ScreenProbes.Tests
• RenderedSceneTestsVixen.Rendering.DistanceFields.Tests
• TracedCardCaptureVixen.Rendering.SurfaceCache
• TracedIrradianceFillerVixen.Rendering.IrradianceFields
• TracedReflectionsVixen.Rendering.Reflections
• TracedScreenProbeGatherVixen.Rendering.ScreenProbes