private static void ConstantAttenuationPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
PointLightBase target = ((PointLightBase)d);
target.PropertyChanged(ConstantAttenuationProperty);
}
private static void RangePropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
PointLightBase target = ((PointLightBase)d);
target.PropertyChanged(RangeProperty);
}
/// <summary>
/// This sets the attenuation and range of a light so that it's a percent of its intensity at some distance
/// </summary>
public static void SetAttenuation(PointLightBase light, double distance, double percentAtDistance)
{
// % = 1/max(1, q*d^2)
// % = 1/(q*d^2)
// q=1(d^2 * %)
light.ConstantAttenuation = 0d;
light.LinearAttenuation = 0d;
light.QuadraticAttenuation = 1 / (distance * percentAtDistance);
// Now limit the range
light.Range = 1 / Math.Sqrt(.01 * light.QuadraticAttenuation); // stop it at 1% intensity
}