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I'm working on photorealistic leaf material that works fine with a plane mesh (of course if it had real geometry thickness the effect would have been easy to set up but heavy for rendering). This is my setup so far: Material setup

If you're wondering about the Fresnel thing, it's explained here. The entire setup is copied from the same guide.

But now my problem is that the backface has no glossy. It's just the diffuse light of the translucency effect.

enter image description here

I know that the down side of real leaves are not as glossy as their top side but there's still a subtle gloss. How can I add a Glossy BSDF For the backface?

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    $\begingroup$ Hi :). You'd need to basically rebuild the Principled BSDF from scratch using other shaders. I did that for another answer, and included that as a nodegroup :)) $\endgroup$
    – jachym michal
    Commented Aug 14, 2022 at 22:37
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    $\begingroup$ Related question with nodegroup included: blender.stackexchange.com/q/215782/78972 $\endgroup$
    – jachym michal
    Commented Aug 14, 2022 at 22:38
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    $\begingroup$ Wow. You have the same setup like mine but you've just seperated the roughness for the two sides. Mine had the glossy effect too but I couldn't control it individually so I thought it was not there. Thanks. You're node group has more controls and is applicable for various cases, especially more complex ones. I'd appreciate it if you post the same images and blend files here as an answer so that I can accept it and give you the bounty. $\endgroup$
    – Barbod M
    Commented Aug 15, 2022 at 12:32
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    $\begingroup$ @JachymMichal Submit an answer please $\endgroup$
    – Barbod M
    Commented Aug 20, 2022 at 6:06
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    $\begingroup$ Posted an answer so your bounty isn't wasted :)). cheers. $\endgroup$
    – jachym michal
    Commented Aug 20, 2022 at 16:50

1 Answer 1

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Posting my own copied answer just so Barbod M's bounty isn't wasted :))

The linked devtalk post already offers a setup for correct backface reflections.
To fine-tune roughness for Frontface/Backface, split the node-tree into two branches.

I used a custom-built PBR shader incorporating Translucency, following CynicatPro's approach.
But you can use a simpler setup as long as the roughness channel is split.



[![enter image description here][4]][4]

For convenience, I packed the whole setup into a nodegroup called Principled Leaves BSDF.

enter image description here





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    $\begingroup$ Just for reference - I used this nodegorup for all foliage in one of my archviz projects and it turned out pretty good :)) $\endgroup$
    – jachym michal
    Commented Aug 20, 2022 at 16:57

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