It works for now. But Corona changed to PB materials and I needed to convert the legacy materials of the hedges and bushes. After conversion the hedges rendered white although in the IR window they seemed ok.
It took me a long time and it seems that sliding the material from left to right over the polygon tag, UV tag and vertex tag and back again in the object manager did the trick. No idea how those tags interact in the newer PB materials and mixture shader of Corona and if they still work as supposed when Darstellungsart set them up.
Anyhow, I find the mixture shaders rather complicated icw vertex maps.
