GLSL semantic for tangent and bitangent? Normal = gl_Normal

Unity Engine
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1

I can’t find any sample of fetching the tangent basis in a GLSL shader. The normal is pretty straight forward, but how do you get the tangent and bitangent/binormal?
Is there a specific binding with another attribute? Something like “the tangent is always in gl_MultiTexCoord7”

Thanks

2

Ah it seems “attribute vec4 Tangent;” is the way to go for tangent, but how about bitangent? (I don’t want to generate it on the fly with cross(), I have flipped UVs shells)

3

Yes, it’s Tangent. Binormal is generated on the fly via cross product. Check out TANGENT_SPACE_ROTATION in UnityCG.glslinc located in your install folder.