A mapping function that can change a value only when it’s zero or very close to it, where it replaces the value with a small constant.
Then, rather than doing a conditional branch which introduces a discontinuity, you can smoothly blend your value with your Threshold.
This is based on Inigo Quilez’s article.
Threshold: The value above which things will be unchanged.
Base Value: The constant value to use when the input is zero.