Author Topic: Turn mesh into corona light  (Read 5618 times)

2021-10-01, 12:36:00

Jak

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Not sure if I am missing anything, but why on earth is this feature not in Corona yet?

Back when I was working on Vray, they had an option to turn any mesh into actualy Vray light (convert the mesh) instead of using light material.

Please add this to corona, being able to convert mesh to actual Corona light, without the need of using corona lightmaterial (that causes noise and other problems, and should not be used to illuminate big spaces).

Thank you.

2021-10-01, 13:09:45
Reply #1

TomG

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Actually any geometry with a Corona Light Material will render as efficiently as if it were a "Corona Light" (with the exception of a sphere, where the spherical Corona Light will in fact render faster and cleaner). Other than that, the Corona Light Material is identical to something being a Corona Light, so any "noise or problems" would be the same if it were a Light as there is no difference in how those are processed/handled.
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2021-10-01, 13:16:43
Reply #2

Jak

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Actually any geometry with a Corona Light Material will render as efficiently as if it were a "Corona Light" (with the exception of a sphere, where the spherical Corona Light will in fact render faster and cleaner). Other than that, the Corona Light Material is identical to something being a Corona Light, so any "noise or problems" would be the same if it were a Light as there is no difference in how those are processed/handled.

Thank you Tom for your reply.

So, if I make a corona disk light (or cylinder), and make a disk/cylinder mesh, and add a corona light material to the latter - both will render:

1) Within the exact time frame achieveing very similar results
2) Will give as much illumination
3) Will be denoised within the same time frame using denoiser
4) Will produce exact amount of noise in very similar situations
5) Will give similar amount of gi to brighten up spaces

If so thats actually interesting, not sure why I have read to stay away from corona light material, and rather use corona lights for gi.


2021-10-01, 13:45:41
Reply #3

romullus

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If so thats actually interesting, not sure why I have read to stay away from corona light material, and rather use corona lights for gi.

You may have read some very old article or tutorial, IIRC back in the old days there was significant difference in speed, between Corona light and mesh light, but that has been resolved long time ago.
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2021-10-01, 13:55:12
Reply #4

TomG

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Right, about what you ask - disks, cylinders, will render the same with a LightMtl as an actual Light (only the sphere is different).

As a note, perhaps you saw something about not using Self Illumination in a CoronaMtl, as that should not be used as a main light source as it is not processed as efficiently.

Also as a note, if you do something like a light bulb filament with lots of faces and fairly complex geometry, naturally this will take longer to sample - just as it would if we happened to have a "Filament" object as a choice in the Corona Light :) Here it is best to use a LightMtl with Emit Light off to give the visible glowing filament, and then say a regular sphere CoronaLight (set to be not visible directly) as the thing that casts light from the light bulb. Perhaps some information like that also lead to confusion?
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2021-10-01, 20:41:43
Reply #5

Jak

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If so thats actually interesting, not sure why I have read to stay away from corona light material, and rather use corona lights for gi.

You may have read some very old article or tutorial, IIRC back in the old days there was significant difference in speed, between Corona light and mesh light, but that has been resolved long time ago.

Ah, I think that might have been it. I had to have missed info on this, thank for filling me in.

Right, about what you ask - disks, cylinders, will render the same with a LightMtl as an actual Light (only the sphere is different).

As a note, perhaps you saw something about not using Self Illumination in a CoronaMtl, as that should not be used as a main light source as it is not processed as efficiently.

Also as a note, if you do something like a light bulb filament with lots of faces and fairly complex geometry, naturally this will take longer to sample - just as it would if we happened to have a "Filament" object as a choice in the Corona Light :) Here it is best to use a LightMtl with Emit Light off to give the visible glowing filament, and then say a regular sphere CoronaLight (set to be not visible directly) as the thing that casts light from the light bulb. Perhaps some information like that also lead to confusion?

Yep, Im aware of the trick to seperate self illuminated sources from actual light emitting sources. I think it was some old info that stuck in the back of my mind some time ago, but since the two are the same now, this renders this thread invalid.

Thank you for the input once again, and for clearing this out.

2021-10-01, 21:27:10
Reply #6

TomG

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Most welcome! It is always good to ask :)
Tom Grimes | chaos-corona.com
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2021-10-02, 09:09:32
Reply #7

Jak

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Most welcome! It is always good to ask :)

One useful thing I tought about having mesh to corona light converter, would be hiding all lights using shortcut command ;) (without actually using layers for this), for scene organisation.

But surely that would be overkill to the amount of programming needed to introduce this, especially since this isnt really a life saving feature.

2021-10-03, 11:27:19
Reply #8

tradstown

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Actually, it will be great to have same way turning mesh in to Corona Light like in V-Ray, because we could find self illumination objects much faster in scene through Corona Listner. Sometimes these objects can give you a lot of noise and you have to check all materials to turn them off. Also, Corona Light material has limitations, for example - intensity.