Chaos Corona Forum

Chaos Corona for Cinema 4D => [C4D] I need help! => Topic started by: TeoRossi93 on 2021-02-16, 22:40:59

Title: Transparent material not behaving correctly with alpha
Post by: TeoRossi93 on 2021-02-16, 22:40:59

Hey guys!
 
I'm trying to render a glass object on a transparent background. Unluckily I'm not able to keep reflections visible in the alpha.
Any ideas on how to keep them visible without rendering a reflection pass and composite it in after/photoshop?

Title: Re: Transparent material not behaving correctly with alpha
Post by: burnin on 2021-02-17, 15:33:30

"Eeryone coins its own luck." ;)
So what's your setup, sys-specs...?

i.e.
Simple setup (W10, R23.110, CRN 7daily) saved as .exr, (16bit) composited in GIMP

(https://forum.corona-renderer.com/index.php?action=dlattach;topic=32443.0;attach=142837;image)

Title: Re: Transparent material not behaving correctly with alpha
Post by: TeoRossi93 on 2021-02-17, 17:53:14

I run c4d r22 and corona 6 for this one (i even run c4d 23 and corona 7 but I just use it for test purpose).
The problem is that I have to composite an animation, no problem to make this work in still images.
Anyway your render looks pretty different from the image opened in gimp.

Title: Re: Transparent material not behaving correctly with alpha
Post by: burnin on 2021-02-18, 01:55:01

Quote from: TeoRossi93 on 2021-02-17, 17:53:14

...your render looks pretty different from the image opened in gimp.

Yup.
And now, something completely different... ;)

(https://forum.corona-renderer.com/index.php?action=dlattach;topic=32443.0;attach=142901;image)

Basically:

Have fun.

Title: Re: Transparent material not behaving correctly with alpha
Post by: ficdogg on 2021-02-19, 16:15:43

I've had to do something similar and I ended up just setting up render passes for reflection and refraction in addition to alpha, and then comped everything in After Effects. You can see the end result here.

t=10s

This was rendered on gray, the blue color and DOF were added in post.