Questions About Backplates

Lan · December 18, 2020, 12:01:09 AM

Hello Keyshot Community, I've tried rendering with a backplate image and the edges of glass becomes dark and shadowed. Does using backplate image directly effect the lighting reflection on a model? I've attached two reference photos, the purple background one I used a backplate image and the other one is with just solid colour. Thanks

DriesV · December 18, 2020, 04:38:13 AM

Hi,

The darkening you are seeing happens because refractions in glass can show parts of the background that are not covered by the backplate. The backplate only fills the frame/image, so for some glass materials with strong refractions, you can see the black surroundings of the backplate image in refractions.

I hope that helps.

Dries

Lan · December 18, 2020, 09:03:51 AM

Hey Dries, thanks for answering my question. How can I create a light source in the background to cover the parts that backplate missed out. I switched between lighting environment, colour, and backplate, and it seems like this only happens when I use a backplate. I'd love to learn how to eliminate the darkening of glass while using a backplate. Thanks again

Best wishes,

Lan

KristofDeHulsters · January 05, 2021, 01:29:54 PM

Your backplate only covers the frame background like Dries said, playing around with HDRI's and making them lighter should resolve the darker parts as it is refracting black portions of your HDRI. Hope this helps.

INNEO_MWo · January 06, 2021, 02:23:53 AM

And increasing the ray bounces should also help

Lan · January 11, 2021, 09:52:06 AM

Quote from: KristofDeHulsters on January 05, 2021, 01:29:54 PM
Your backplate only covers the frame background like Dries said, playing around with HDRI's and making them lighter should resolve the darker parts as it is refracting black portions of your HDRI. Hope this helps.

Hey KristofDeHulsters, thanks for the response. What I've done now is to add a plane and set it to flat with the same colour as the backplate to covers the dark reflected parts. I'll try to increase the brightness and see if that will help.

Lan · January 11, 2021, 09:55:49 AM

Quote from: INNEO_MWo on January 06, 2021, 02:23:53 AM
And increasing the ray bounces should also help

Hey INNEO_MWo, thanks for the tip. I'll tweak around to see if that works. Does Global Illumination Bounces affect the reflected lights on the edges as well?

INNEO_MWo · January 11, 2021, 10:05:38 AM

it should effect the brightness of the entire scene in certain ways

Cheers
Marco