Author Topic: [Solved] light include only decals  (Read 1705 times)

2023-05-30, 18:50:15

LorenzoS

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Hi,
there is a way to use a ligth that include only a decals and not the surface to witch it is applied?
I cann't do it.

Max 2022 corona 9 hotfix3.

thanks
« Last Edit: 2023-05-31, 15:04:41 by Aram Avetisyan »

2023-05-30, 19:54:55
Reply #1

TomG

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I am not 100% sure of what you mean - do you mean you want the decal to emit light (while the rest of the object the decal is on does not)? If so, using Self Illumination in the Corona Physical Material does that. If that's not what you meant though, let us know!
Tom Grimes | chaos-corona.com
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2023-05-31, 08:34:44
Reply #2

LorenzoS

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see attachments,
in 2.jpg, where CoronaLight001 include only corona Decal001, the result is not as aspecteded.

2023-05-31, 10:42:06
Reply #3

Aram Avetisyan

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Hi,

I am not sure what is the reason and exact case that you want to do this, if I understand it correctly.
You want a light to illuminate only the projected part of the decal on the surface, and nothing else, right?

It makes sense, but why would you do so?
Aram Avetisyan | chaos-corona.com
Chaos Corona QA Specialist | contact us

2023-05-31, 10:51:47
Reply #4

LorenzoS

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Quote
You want a light to illuminate only the projected part of the decal on the surface, and nothing else, right?
yes.

Quote
It makes sense, but why would you do so?
becouse decals are metallic letters on floor and i need more reflection on those (my client ask for that).

2023-05-31, 12:06:10
Reply #5

Aram Avetisyan

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That is not the optimal way of doing it.

Just change the metalness in decal material to "Metal" from "Non-metal", and decrease the roughness if necessary.
You can as well try increasing the IOR/Specular level of the material with Non-metal metalness.

Hope this helps.
Aram Avetisyan | chaos-corona.com
Chaos Corona QA Specialist | contact us

2023-05-31, 12:19:22
Reply #6

LorenzoS

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Thank you Aram for replay,
the files i attached in post is only a sample, i can't post for copyright reason the real image.
Yes, the decal material is set to metal on my work project obviously.
In my workflow many times i use a ligth only to increase refection on metal surface, but with decal not works.

2023-05-31, 14:19:05
Reply #7

romullus

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Decal is not an object, but rather a helper/mapping projector, therefore it can't be used in lights include/exclude list. If you really need to use separate lighting for decal, consider replacing it with floating plane object with opacity. You can use it in combination with rayswitch material, so that it does not cast shadow on the base object. This technique can be somewhat tricky to use if your base object is not flat, or it has pronounced displacement, but even in such case it's not impossible.
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2023-05-31, 14:40:01
Reply #8

LorenzoS

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consider replacing it with floating plane object with opacity. You can use it in combination with rayswitch material
Thank you romullus,
works well in my case.

2023-05-31, 14:53:02
Reply #9

romullus

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Glad to hear that. Sometimes old school techniques are the best :]
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2023-05-31, 18:15:17
Reply #10

maru

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Another option I can think of would be using an environment reflection override in the material which is assigned to the decal object.
Marcin Miodek | chaos-corona.com
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2023-05-31, 18:32:43
Reply #11

LorenzoS

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Another option I can think of would be using an environment reflection override in the material which is assigned to the decal object.
seems don't work for me.

2023-05-31, 19:07:24
Reply #12

romullus

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It will only work if environment is unobstructed by other objects, i.e. if object with decal is rendered isolated against solid background, or global environment. In most cases this won't work, because object in question can't see environment, because it is surrounded by other objects.
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2023-05-31, 20:34:37
Reply #13

LorenzoS

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It will only work if environment is unobstructed by other objects, i.e. if object with decal is rendered isolated against solid background, or global environment. In most cases this won't work, because object in question can't see environment, because it is surrounded by other objects.
I've tried everything but can't get it to work

2023-05-31, 21:16:30
Reply #14

romullus

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Just tried to override decal material's reflections and indeed it looks that it doesn't work, at least not in Corona 9. Maybe it works in Corona 10 where decals has been enhanced with affect only selected channel option?
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