I may have spoken too fast. You should first set the texture on the wall and check if it renders correctly, even if transparency will appear as a black color on the wall. You should also change the thickness of the wall with the smallest value and set a top color on it to be able to make the matching material invisible afterwards.
Then export the wall to OBJ format, reimport it and hide the top color material.
See attached file if needed.
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TransparencyTestOnExportedWall.sh3d
(698863 bytes)
(Download count: 147038)
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Emmanuel Puybaret, Sweet Home 3D creator
