flipped textures in alembic vray proxy?

[mistafunk]

hi forum,

i am writing a post translation script to assign custom material properties to a vray proxy. both the proxy and the custom material properties come from the same alembic file. i am seeing a problem where the each texture is somehow flipped in v direction. the same alembic file looks fine in e.g. houdini. in this screenshot you see on the left vray with the flipped texture and on the right the original scene: https://tresor.it/s#VE_7Udqgb8xP5-sfG8JITQ (i could not directly upload an image).

i tried multiple things like flipping the texture file and/or transforming the UVs - nothing helps.

TIA,
simon

[vlado]

What file format are the textures in?

Best regards,
Vlado

[mistafunk]

hi vlado,

it is a tiff: https://tresor.it/s#wJruhPs6rCVPYulqfqSHHg

best,
simon

[vlado]

What happens if you try f.e. JPG or PNG?

Best regards,
Vlado

[mistafunk]

hi vlado,

this is not a problem of the image file but of the UVs. it seems that vray has a different UV coord system definition than e.g. when i try to render the same alembic file with houdini/mantra or katana/prman. what is vray doing differently in terms of UVs?

here is what i am doing in maya (maya2016 + latest vray plugin demo):
1. import alembic file as proxy
2. check "full names" so post translation script finds alembic nodes
3. attach a post translation script (via "snippet")
4. render

screenshot, alembic file, post translation script and "snippet" are here: https://esri.box.com/s/jbe9xrgd1p35tym0dwk14qkr2xhp4k19