The lighting information in the light probesLight probes store information about how light passes through space in your scene. A collection of light probes arranged within a given space can improve lighting on moving objects and static LOD scenery within that space. More info
See in Glossary are encoded as Spherical Harmonics basis functions. We use third order polynomials, also known as L2 Spherical Harmonics. These are stored using 27 floating point values, 9 for each color channel.
The EnlightenA lighting system by Geomerics used in Unity for Enlighten Realtime Global Illumination. More info
See in Glossary Realtime Global IlluminationA group of techniques that model both direct and indirect lighting to provide realistic lighting results.
See in Glossary implementation in Unity uses a different spherical harmonics approach than Geomerics, the feature’s original developer, namely the notation and reconstruction method from Peter-Pike Sloan’s paper, Stupid Spherical Harmonics (SH) Tricks. Geomerics’ original approach was based on the notation and reconstruction method from Ramamoorthi/Hanrahan’s paper, An Efficient Representation for Irradiance Environment Maps.
The shaderA program that runs on the GPU. More info
See in Glossary code for reconstruction is found in UnityCG.cginc and is using the method from Appendix A10 Shader/CPU code for Irradiance Environment Maps from Peter-Pikes paper.
The data is internally ordered like this:
[L00: DC]
[L1-1: y] [L10: z] [L11: x]
[L2-2: xy] [L2-1: yz] [L20: zz] [L21: xz] [L22: xx - yy]
The 9 coefficients for R, G and B are ordered like this:
L00, L1-1, L10, L11, L2-2, L2-1, L20, L21, L22, // red channel
L00, L1-1, L10, L11, L2-2, L2-1, L20, L21, L22, // blue channel
L00, L1-1, L10, L11, L2-2, L2-1, L20, L21, L22 // green channel
For more “under-the-hood” information about Unity’s light probe system, you can read Robert Cupisz’s talk from GDC 2012, Light Probe Interpolation Using Tetrahedral Tessellations”, GDC 2012
Did you find this page useful? Please give it a rating:
Thanks for rating this page!
What kind of problem would you like to report?
Thanks for letting us know! This page has been marked for review based on your feedback.
If you have time, you can provide more information to help us fix the problem faster.
Provide more information
You've told us this page needs code samples. If you'd like to help us further, you could provide a code sample, or tell us about what kind of code sample you'd like to see:
You've told us there are code samples on this page which don't work. If you know how to fix it, or have something better we could use instead, please let us know:
You've told us there is information missing from this page. Please tell us more about what's missing:
You've told us there is incorrect information on this page. If you know what we should change to make it correct, please tell us:
You've told us this page has unclear or confusing information. Please tell us more about what you found unclear or confusing, or let us know how we could make it clearer:
You've told us there is a spelling or grammar error on this page. Please tell us what's wrong:
You've told us this page has a problem. Please tell us more about what's wrong:
Thank you for helping to make the Unity documentation better!
Your feedback has been submitted as a ticket for our documentation team to review.
We are not able to reply to every ticket submitted.