Hi,<br>I came across what looks like either an OpenGL bug or an XCrysDen bug with transparencies. I'll try to describe the problem step by step.<br><br>1. Take a wave function of a simple molecule or polymer. <br><br>2. Select a reasonable iso-value (but don't check the "render +/- isovalue" box. The problem is clearer this way). The lobes of the wave function should be visible and not transparent (default) as expected. So far so good.
<br><br>3. Now, turn the transparency on. The lobes appear transparent and the overall picture looks fine. <br><br>4. Click on the "Set TRANSPARENCY parameters" box and go to the "Front Side Color" tab. In my default configuration the only parameter with an alpha component lower than
1.00 is the "Diffuse color" (0.60). Move it to 1.00 so that all the alpha components are 1.00. Click "Update". This should - if I understand it correctly - make the system completely opaque. (You can also set to
1.00 the alpha of the diffuse color on the back side color tab, but nothing changes).<br><br>5. Now the problem: rotate the molecule. From directions with positive x, y, z the lobes look opaque as they should. However as you look at the system from the opposite direction the lobes in the front appear in the back and vice versa, as if the "painter algorithm" is getting the objects sorted backwards.
<br><br>So, has anyone seen this before, and is this something really simple to correct? I got into this because I want transparent wave functions but not too transparent, so I need to play with the alpha settings. <br><br>
Thanks in advance.<br><br>Filipe<br> <br><br>-- <br>-------------------------------------------------------------------------<br>Filipe J Ribeiro<br>University of California, Berkeley<br>Department of Physics<br>366 LeConte Hall # 7300
<br>Berkeley, California 94720-7300<br>USA<br>Phone: 510.643.3374<br>Fax: 510.643.9473<br><a href="http://civet.berkeley.edu/~fribeiro">http://civet.berkeley.edu/~fribeiro</a><br>-------------------------------------------------------------------------