Is Luxcore capable of rendering Fraunhofer diffraction?

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Qclem23
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Joined: Wed Oct 28, 2020 5:00 pm

Is Luxcore capable of rendering Fraunhofer diffraction?

Post by Qclem23 » Tue Sep 14, 2021 8:04 pm

I am trying to render shadows cast by the sun shining through foliage. I am particularly interested in capturing the mysterious way that they shift around.
https://www.youtube.com/watch?v=BCYDxBEuZBs
Here is light distorted by a tree trunk at 20 meters causing the shadow of my hand to shift:
https://drive.google.com/file/d/1M-uas4 ... sp=sharing
I have come to understand that this is due to Fraunhofer diffraction.
https://www.scientificpsychic.com/bloge ... -ears.html
I have tried some experiments with LuxCore but I don't understand enough to even be sure that the shifting I can see in the render is due to Fraunhofer diffaction.
https://www.dropbox.com/s/28c3i633821ya ... y.mp4?dl=0
Is Luxcore capable of rendering Fraunhofer diffraction and how would be the best way to set up Luxcore in Blender to optimize it for this effect?

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B.Y.O.B.
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Re: Is Luxcore capable of rendering Fraunhofer diffraction?

Post by B.Y.O.B. » Tue Sep 14, 2021 9:40 pm

LuxCore doesn't simulate light as waves, so it can't do any effects that depend on wave interactions.

However, I'm not sure if the effect in your video is due to diffraction, it might be something else.
For example, I've attached a file with an interesting shadow effect, might be a starting point for experiments.

Video: https://youtu.be/kFRcSMzko4A
Attachments
interesting_shadow_02.zip
(112.21 KiB) Downloaded 9 times

Qclem23
Posts: 3
Joined: Wed Oct 28, 2020 5:00 pm

Re: Is Luxcore capable of rendering Fraunhofer diffraction?

Post by Qclem23 » Wed Sep 15, 2021 6:33 pm

Thank you for taking the time to reply! Could you tell me if the sun in LuxCore behaves exactly the same as the real sun? I have very little scientific education but I believe that I have observed a curious interection between the constant angular diameter of the sun, parallel light, and the varying angular diameter with distance of the near objects that cast shadows. I think this could possibly help explain the effect. I will try to get this down as a Blend file, but I need to be sure that the sun will behave correctly or if it would be safer to use a spot with a large diameter placed at a large distance to simulate the sun.

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