Twosided materials are not lit correctly when receiving light on the backface

I’m using two-sided materials in my project for things like fences and foliage and I am finding that the lighting is inverted when they are lit from the backfacing side.

285750-twosided-foliage-gif.gif

Is there a way to fix this? I’m hoping to avoid having to model the backfaces into all of my meshes…

I suppose in some cases it is actually “correct” to render inverted normals for backfaces, but I honestly cannot think of very many situations where this would be desirable.

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I don’t work with normal maps but I know there is a node called Two Sided Texturing. Maybe you can use the regular normal in input A and inverted in input B of that node.

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Thanks a ton man, it worked. I didn’t know this node even existed.

As MMMarcis answered in the comments, the way to fix this is to use the two-sided texturing node, with the backface using an inverted normal. Just submitting this so I can flag the question as answered.

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