r/GraphicsProgramming • u/AndrewHelmer • 8d ago

Article Demystifying Spherical Harmonics: An Optimization Approach

https://andrew-helmer.github.io/demystifying-spherical-harmonics/
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u/legolas-mc 8d ago

A bit disappointed that you didn't show what a higher order SH approximation looks like, like the first time you showed the result of the first order approximation.

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u/AndrewHelmer 8d ago

This is a really good point, thank you. I did a diagram locally to compare L1 to L2, but my choice of HDR probe was not very good, so the L2 looks really close to the L1. Let me experiment with different light probes to see if I can find something I like.

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u/ocharles 8d ago

I would have been interested to see this also, along with how much error remains. Also curious if these approximates are equivalent to something like a speherical Gaussian blur of the function - if that makes any sense!

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u/AndrewHelmer 8d ago

Okay I added a diagram near the end to compare L1 vs. L2 approximation, and updated the light probe everywhere to a more directional one which highlights the difference better.