Questions about direct light sampling in global illumination

[neross666]

1. Does the code in line 553 in the indirectdiffuse.cpp file do more calculations for dividing the pdf?
2. Spherical attenuation calculations (divided by the square of the distance) are performed for the sampling of direct light, but not for the transmission of indirect light, so why don't we need to do this part of the calculation for the transmission of indirect light?

[scratchapixel]

All good questions) Would you mind sending them on Discord?)

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On 27 Sep 2024, at 05:47, neross666 ***@***.***> wrote: Does the code in line 553 in the indirectdiffuse.cpp file do more calculations for dividing the pdf? Spherical attenuation calculations (divided by the square of the distance) are performed for the sampling of direct light, but not for the transmission of indirect light, so why don't we need to do this part of the calculation for the transmission of indirect light? — Reply to this email directly, view it on GitHub <#7>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABG4EWM45V7D5VQFZYC4U2TZYTIMLAVCNFSM6AAAAABO6J2GNKVHI2DSMVQWIX3LMV43ASLTON2WKOZSGU2TCOJSHE2TOMY>. You are receiving this because you are subscribed to this thread.

[neross666]

All good questions) Would you mind sending them on Discord?)
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On 27 Sep 2024, at 05:47, neross666 @.***> wrote: Does the code in line 553 in the indirectdiffuse.cpp file do more calculations for dividing the pdf? Spherical attenuation calculations (divided by the square of the distance) are performed for the sampling of direct light, but not for the transmission of indirect light, so why don't we need to do this part of the calculation for the transmission of indirect light? — Reply to this email directly, view it on GitHub <#7>, or unsubscribe https://github.com/notifications/unsubscribe-auth/ABG4EWM45V7D5VQFZYC4U2TZYTIMLAVCNFSM6AAAAABO6J2GNKVHI2DSMVQWIX3LMV43ASLTON2WKOZSGU2TCOJSHE2TOMY. You are receiving this because you are subscribed to this thread.

I don't mind at all, it's just that I haven't been able to use Discord due to internet restriction issues. I'd also like to make a donation to the author, but that's also not been possible due to internet restriction or payment limitations!

[scratchapixel]

No worries. Where are you from if I may ask? You can reply directly to me at ***@***.*** ***@***.***> What I am going to do is reply to your interesting questions directly in the lesson (which I guess you have no problem to access to). I will do this this week.

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On 27 Sep 2024, at 10:24, neross666 ***@***.***> wrote: All good questions) Would you mind sending them on Discord?) … <x-msg://29/#> On 27 Sep 2024, at 05:47, neross666 @.***> wrote: Does the code in line 553 in the indirectdiffuse.cpp file do more calculations for dividing the pdf? Spherical attenuation calculations (divided by the square of the distance) are performed for the sampling of direct light, but not for the transmission of indirect light, so why don't we need to do this part of the calculation for the transmission of indirect light? — Reply to this email directly, view it on GitHub <#7 <#7>>, or unsubscribe https://github.com/notifications/unsubscribe-auth/ABG4EWM45V7D5VQFZYC4U2TZYTIMLAVCNFSM6AAAAABO6J2GNKVHI2DSMVQWIX3LMV43ASLTON2WKOZSGU2TCOJSHE2TOMY <https://github.com/notifications/unsubscribe-auth/ABG4EWM45V7D5VQFZYC4U2TZYTIMLAVCNFSM6AAAAABO6J2GNKVHI2DSMVQWIX3LMV43ASLTON2WKOZSGU2TCOJSHE2TOMY>. You are receiving this because you are subscribed to this thread. I don't mind at all, it's just that I haven't been able to use Discord due to internet restriction issues. I'd also like to make a donation to the author, but that's also not been possible due to internet restriction or payment limitations! — Reply to this email directly, view it on GitHub <#7 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABG4EWNC6QYNFRWMHDRNVGLZYUI2NAVCNFSM6AAAAABO6J2GNKVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDGNZYG4ZDQMJVHE>. You are receiving this because you commented.

[scratchapixel]

I am just about to address you second point, but can you elaborate on this question please? I don’t understand what you mean? Thx

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On 27 Sep 2024, at 05:47, neross666 ***@***.***> wrote: Does the code in line 553 in the indirectdiffuse.cpp file do more calculations for dividing the pdf?