Author Topic: Bending light through prism  (Read 3579 times)

2017-10-29, 19:18:28

Pavel Vinter

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Hi Guys,
I went into this problem when I was trying to simulate disperse light beam into spectre. I thought maybe new Corona 1.7 will solve it, but no luck so far. I wanted to bend a beam of light going through prism. So I created Corona light with maximum directionality 0,99 and Global Volume Mtl. I also add some scattering with high directionality in the glass itself to make the light visible. Is my concept totally wrong? I would expect the beam to bend according on the IOR refr value, but it's just going through.
My goal was to disperse this beam into spectrum, does anyone has any thoughts how to achieve that?

Thanks, Pavel

2017-10-29, 21:16:03
Reply #1

romullus

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AFAIK, Corona does not do spectral rendering. Ray travelling and scattering will be correct, but you won't get white light dispersion in to spectrum. I remember there was interesting discussion going on in the forum about spectral rendering many years ago, you may try to search for it if you're feeling lucky :]
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2017-10-30, 09:51:18
Reply #2

maru

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Looks like it is kind of working with BDPT. :)
More info - https://coronarenderer.freshdesk.com/support/solutions/articles/12000021288
Marcin Miodek | chaos-corona.com
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2017-10-30, 14:27:14
Reply #3

Pavel Vinter

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Thanks a lot! I can definitely see some rainbow now, great! I guess with BDPT it's impossible to see any volumetric scattering right? I had to add parallel plane to see the result and the beam also disappers inside the prism :(

2017-10-30, 15:30:40
Reply #4

maru

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Now that is starting to look like some proper retrowave art! ;)
Remember that other engines such as BDPT are experimental, and they do not support many features... There are definitely problems when using volumetric fog, but you can check what happens when using other solvers.
Marcin Miodek | chaos-corona.com
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2021-03-12, 11:33:13
Reply #5

Gabiru

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i want to understand this, i want to recreate dark side of the moon album art but i cant make this, never made such a scene cant even simulate the rays going through the prism
can you help me at this @maru?

Theres an image from what i have now, the render times are just insane, not sure what im doing wrong also the light refracted is not doing the path that i expected, the pirsm itself i was thinking it would be whiter with the refraction but still to dark, any help? seems like the only part thats ok is the white light ray outside the prism

Tried to use a gradient ramp on refraction material but also not working its just refracting the red.
« Last Edit: 2021-03-12, 15:19:30 by Gabiru »

2021-04-16, 09:37:10
Reply #6

Aram Avetisyan

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The thing with dispersion/caustics for a specific scene or effect you are trying to achieve, the cover of Dark side of the moon album in this case, needs a bit of planning ahead to get what you want with reasonable times and optimized scene.
Here is a result I got.
If you use volumetrics alongside with caustics and dispersion, chances are you will never get a clean render.
The light you see in the render below is not "in the air" or "in a volume". The light source is casting light on a plane on which the prism is set. The render is kind a plan view of everything going on.
There are alos other subtleties to consider while creating this, like light source intensity and its rotation, another auxiliary light source for composition, abbe number of the material etc.

Aram Avetisyan | chaos-corona.com
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