I am using the URP Lit shader for these trees. I want the underside of the leaves to render, but they currently look as though they are receiving the light from the front (it's too bright). How do I get the underside of these leaves to look dark?
#Question about URP lit shader
karmic shard
willow iron
I am using the URP Lit shader for these trees. I want the underside of the leave...
I presume you set the leaf material to render face: both?
If so, that renders light on only the front face, and duplicates it on the back face
You could make a shader graph that flips the normal to always face you so you only see the front face, but it can be inconvenient to make a new lit shader just for that
Another option is to duplicate the leaf polygons in a mesh editing program and flip their normals
That could also be done non-destructively and automatically with a modifier, like Blender's Solidify without edge geometry enabled
karmic shard
Ok, so this is a "limitation" of the shader. Say I use blender to flip the mesh normals. What would that do to the top of the leaves? Would they now be dark if I rotated the camera around?
willow iron
Ok, so this is a "limitation" of the shader. Say I use blender to flip the mesh ...
It would, but the point is you duplicate before flipping
karmic shard
ah, I see
willow iron
So you've got two layers of leaves overlapping exactly, facing different directions
karmic shard
right. Ok, thanks for the feedback!
willow iron
It doubles the geometry for them, but geometry is relatively not expensive
Having to swap to a different shader during rendering hinders batching a bit
So I would usually prefer the extra geometry method
However if you also do vertex animation for wind or the like, using the mesh normals, then the undersides can become detached from the top sides of the leaves