Author Topic: PNG file output and reflection  (Read 220 times)

2021-10-13, 09:58:51

aaouviz

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So, I have had discussions on this topic in the past, but I can't find them unfortunately...but I'm either amazed this hasn't been fixed, or I'm missing something...

I'm wondering why I still have issues with losing 90% window glass reflections when I save a Corona Render to PNG. If there is only sky (and no geometry) in the background behind the glass the PNG is saved with basically no reflections in the windows...

Please see attached screenshots for an example. All materials are from the corona material library (the glass has 5mm thickness), the scene is using only corona sun and sky.

As you can see if I save out a JPG the sky is visible and the reflections are strong. If I save out a PNG and put the same sky in the background (in photoshop) the reflections are almost completely gone...

I don't want to have to save out the reflection pass every time and do this is post, I feel this should work as expected properly. Am I missing something?

btw the I'm saving out from CIE. Not the VFB.

2021-10-13, 17:29:06
Reply #1

NicolasC

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Hello,

Embedded alpha in the PNG maybe ?
Nicolas Caplat
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2021-10-13, 17:39:59
Reply #2

aaouviz

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Hi, thanks for the reply :)

Do you mean the "include alpha channel" tick box when saving to *.PNG?

2021-10-13, 18:18:02
Reply #3

NicolasC

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Yup.
Nicolas Caplat
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2021-10-14, 08:28:10
Reply #4

aaouviz

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Doesn't help unfortunately.

Unless I've been doing something catastrophically wrong.... I've been trying to figure this out for 3+ years, chatted with Devs about it and it's still persists.

Not sure if it bothers others as much as it does for me though

2021-10-14, 09:42:54
Reply #5

NicolasC

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Good morning,

That's weird indeed - at first I thought reflections were softened because of your alpha, but if it's not this, I don't know ... I will have to find some time to test on my side.
Nicolas Caplat
CG supervisor / teacher / artist

2021-10-14, 10:52:25
Reply #6

LorenzoS

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From my experience the problem is that alpha channel conserve also the refraction.
So it's difficult to change in post production the background.