Dear Bertalan,Unfortunately BILD transparency is not working in Chimera. This was reported a long time ago but never got fixed.
However, it does work correctly in ChimeraX. See attached screenshot of your file opened in Chimera (top) and in ChimeraX (bottom).
Depending on what else you needed to do, maybe you can use ChimeraX instead?
Sorry for the inconvenience,
Elaine
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Elaine C. Meng, Ph.D.
UCSF Chimera(X) team
Department of Pharmaceutical Chemistry
University of California, San Francisco

On Jan 14, 2019, at 8:19 AM, Kovács Bertalan <kovacs.bertalan@itk.ppke.hu> wrote:
Dear Chimera Users,
I drew a polygon and a sphere in BILD format, and I was trying to make the polygon transparent so that when the sphere is behind it, it does not hide the sphere completely. I noticed however, that the .transparent command in BILD does not actually make the polygon transparent, it just makes it more pale by making its color resembling more and more to the background. Generally, that is what you would expect from 'transparency', but it still hides the objects (the sphere) behind it, which I was trying to make visible even through the polygon in the first place.
Did anyone else had this problem? I attach my code below.
Thanks,
Bertalan Kovács
Pázmány Péter Catholic University
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.color red
.sphere 0 0 5 1
.color blue
.transparency 0.8
.polygon 5 0 0 0 5 0 -5 0 0 0 -5 0