public static float SmoothStep(float value1, float value2, float amount)
{
float num = MathHelper.Clamp(amount, 0f, 1f);
return MathHelper.Lerp(value1, value2, num * num * (3f - 2f * num));
}
public static float CatmullRom(float value1, float value2, float value3, float value4, float amount)