Rays lose LF and HF energy separately based on how far they travel through air. There is an in-built air absorption formula that's based on humidity, temperature and pressure. You can adjust each value via this `airAbsorption` object: ```cs var settings = new RaytracingContextSettings(); settings.airAbsorption.HumidityPercent = 0.1f; settings.airAbsorption.TemperatureFarenheit = 78.8f; settings.airAbsorption.PressurePascals = 101325; ``` Air absorption is also affected by the `metersPerUnit`, `speedOfSound`, `frequencyReferenceLF` and `frequencyReferenceHF` settings. Read more: [[Creating a Raytracing Context]]. You can also provide custom formulas for air absorption: ```cs settings.airAbsorption.CustomFormulaLF = (float distance) => { // Return how much LF energy should be lost, in the range 0.0 to 1.0 return distance / 15000.0f; }; settings.airAbsorption.CustomFormulaHF = (float distance) => { // Return how much HF energy should be lost, in the range 0.0 to 1.0 return distance / 2000.0f; } ``` You can also completely disable air absorption: ```cs settings.airAbsorption = null; ``` ## Reference View the `AtmosphericAbsorption.cs` file in the `SDK > References` folder to see how the default air absorption formula works.