Superfly transparency

  • There's something weird about the way that the superfly renderer handles bitmapped transparency maps. It seems fine with black or white, but shades of grey cause distortions. This is apparent here on a skullcap that uses a Posersurface with greyscale transparency. I had read something about an interaction with EZDome causing thos, but this sample does not USE easy dome - it's the default light setup.
    If I switch and use a superfly set up, plugging the tranparency into fac, and using a transparency node, I get a similar effect OR a kind of shadow noise pattern.
    If I plug in a simple sharp edged black white checkerboard pattern to the FAC, it works as expected, but when I add a grey scale mortar thickness, the mortar does NOT work as expected.

    Does anyone have any thoughts on this please?

    0_1482879935023_transparency hair.jpg

  • @matb Hey Mat,

    If you are using EZDome for light this will happen. Current bug in Superfly that will make transparent objects cast shadows with the double EZDome. Remove the inner dome and that should go away.

    If not then switch root nodes for that transparent object. The three roots do not treat transparencies the same way. I'm using the Poser root for hair transparencies right now.

  • @ghostship Hey Ghost cheers for your thoughts but this IS a Posersurface. It's just as bad with a superfly root node, and no, I'm not using EZ dome. I can't use the Poser surface root as a long term - I need transparency for skin objects too.

  • Check your sss node on the forehead. Where this looks like a glow rather than a shadow, it could be that you need to increase the sharpness value a tiny bit. It can't be at 0 if you're using the superfly node or change the scatter group if you're using the Subsurface skin node.

  • @redphantom I was so excited to read this because I thought it was going to solve another earlier problem as well, namely that even with no lights on my texture was glowing - self illuminating. I don't recall how I fixed that, but this one doesn't do it. Sadly, increasing the sharpness in .1 increments from 0-1 has not resolved the issue.
    It's clear that this glow as you correctly point out, precisely follows the line of the hair's skullcap. I've coloured it green here so that you can see.

    0_1482936763279_transparency hair green.jpg

    There is clearly a negative interaction between the skullcap and the skin. I'm including snapshots of my skin node in case it gives you a clue, but it seems pretty vanilla to me.

    0_1482937198094_transparency nodes.jpg

    I'd show you the skullcap nodes but apparently it's against the rules of the forum to do so. Suffice it to say, that whilst the original does some weird stuff with specularity, even when reduced to its absolute basics (transmaps and texture), the effect persists.

  • Try this:

    1. Change texture blur to not-zero.
    2. It may eliminate glow, but make thin black lines where skullcap and head intersect each other. Only 100% solution is morph skullcup.

  • @phdubrov That's it, fixed! Thanks so much to everyone for offering their help. Now would phdubrov and redphantom please explain to me in simple language why theire offerings made a difference! I've read the manual, but the explanation therew does noes explain why the base texture interacts solely with overlaid transparency in this way.

    Sooo happy to have resolved this issue!