Author Topic: [RESOLVED] Decals, reflection altough 0% gloss  (Read 2069 times)

2023-05-28, 23:27:15

lollolo

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Hi

Latest build and c4d r20 on win10.
If I use Corona Decal on a simple black plane, the result is always very glossy, although my materials have 0% glossiness. So there should be no reflections at all. But when I check "Clip" under the opacity settings of my decal material, I get correct results, without any reflections.
Seems to me there is an issue, could you check it? 


Thanks!

Edit: I downgraded to the daily build before (April 3) and this resolved my issue. So my reported issue is only in the latest build.

« Last Edit: 2023-06-19, 12:24:22 by Beanzvision »

2023-05-30, 16:11:54
Reply #1

TomG

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I may just be confused here, but that doesn't look like Glossiness to me, but Opacity - you are seeing through the object due to opacity, there's no reflection / refraction going on there. Can you share the scene, since it looks like a simple test scene?
Tom Grimes | chaos-corona.com
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2023-05-31, 12:52:12
Reply #2

lollolo

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I may just be confused here, but that doesn't look like Glossiness to me, but Opacity - you are seeing through the object due to opacity, there's no reflection / refraction going on there. Can you share the scene, since it looks like a simple test scene?
I don't think it's opacity, although it happens only if opacity of the decal material is lower than 100%.

Here my setup: plane with a black material, 0% glossiness.
Decal with a white color in diffuse slot and a noise in opacity channel. Glossiness also 0%.
In the second image, I rendered the same scene again, but using April 3 build, and got correct results, without reflections on my plane.

Hope this will be fixed till the final release :)

2023-05-31, 13:18:12
Reply #3

TomG

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It's not reflection, it's the opacity - I placed a red cube behind the object, and a blue cube in front of it, and you can see the red cube through it but no reflection of the blue cube.

From what I can see, this is expected - the decal has opacity, it's replacing the opacity of the original plane, so now you can see through the plane based on that opacity.

PS - if you are using Corona 10 daily build, you can disable "Replace Opacity" which I think may be the effect you are looking for.
Tom Grimes | chaos-corona.com
Product Manager | contact us

2023-05-31, 13:47:33
Reply #4

lollolo

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It's not reflection, it's the opacity - I placed a red cube behind the object, and a blue cube in front of it, and you can see the red cube through it but no reflection of the blue cube.

From what I can see, this is expected - the decal has opacity, it's replacing the opacity of the original plane, so now you can see through the plane based on that opacity.

PS - if you are using Corona 10 daily build, you can disable "Replace Opacity" which I think may be the effect you are looking for.

Thanks for the hint with "Replace Opacity". I will check it out when i find some free minutes.
But still, why does it override when I have values between 1% and 99% opacity, but not when I have 0% (full black) and 100% (full white) opacity? this makes no sense to me. (Check my first post, when I check "Clip" in opacity channel, I get different results. Why?
« Last Edit: 2023-05-31, 13:51:54 by lollolo »

2023-05-31, 15:35:13
Reply #5

TomG

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Opacity in decal material serves two purposes if Affect is on (which it always was prior to Corona 10):
1) Mixing with the base material
2) Changing base material opacity

This results in opacity 1 being solid, with decal material, and opacity 0 also being solid but with base material, while in between is a blend of both PLUS a change in opacity overall.

To control overall opacity separately, you should set the Mask Source from "Map" (from Shader, in C4D) rather than from the material's Opacity channel. Hope this helps!
« Last Edit: 2023-05-31, 15:38:35 by TomG »
Tom Grimes | chaos-corona.com
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2023-05-31, 16:45:01
Reply #6

lollolo

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Aaah, thank you, this makes much more sense already :)

And please make a note in the help desk for that, I don't think I'm the only one who did't understand how the new decals work in terms of opacity.
« Last Edit: 2023-05-31, 16:48:27 by lollolo »

2023-05-31, 17:20:50
Reply #7

TomG

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For sure, we've made a note for the video tutorial too :)
Tom Grimes | chaos-corona.com
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2023-06-18, 23:19:58
Reply #8

lollolo

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This topic is 100% resolved, and can be deleted or moved.
 
Thanks for your answers. :)