I've made some searches first but I guess that as I'm new, I must not use the good terms
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I've made a little model, and UV hand textured it.
It's okay for the first part, but then I've added 2 little polygon plane on it, then UV it.it's fine from face, but the rear side is all dark.
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My renderer options are like these, and I use the default lighting :
Options>viewport 2.0
--Transparency Algorithm set to depth peeling
--Transparent shadows on (to get rid of the shadows on the plane)