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Thread: Plane with black and white clip and transparency problem

  1. #1

    Plane with black and white clip and transparency problem

    Hello
    I used to add some planes with a slow smoke image sequence to simulate quick and dirty ground fog swirling or some cheap smoke. Now in LW 2018 /2019, the white transparent zone of the image / clip still renders transparent white instead of invisible. Clip map can't be used for obvious reasons (need gradual transparency on smoke) . Playing with refraction / transparency rays don't change a thing. I must be missing something obvious...
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  2. #2
    RETROGRADER prometheus's Avatar
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    I donīt see an issue with applying a clip and it is transparent.
    I donīt think it has something with the refraction, but rather the clip itself..if the part that is supposed to be black isnīt purely black..have you tried other clips? deactivate the clip and ad a procedural texture layer first to check it out, if you got that working ok..then you now it is the clip that has the issue, or a setting in the image editor..maybe color space or something else.
    However..if the procedural texture applied also yields the same issue, it could be something in the render setting, or the material itself.

    And...do you really need the clip map, instead of just using transparency only, with clip map you will get a very sharp cutoff, with transparency only..the clip would be much smoother blending in..I think.

  3. #3
    By clip I mean a video clip, not a clip map as I need progressive transparency in the smoke area. The problem comes from the transparency It self, clip works as expected (just not what I need in that example)
    Prometeus, while you're here, I was trying to find one of your post, some earthquake example, where you put the classic gradient based on a null distance to control the glue amount of the bullet simulation. The other setting was, if I remember correctly, a gradient (based on the distance from a null as well) in the density channel. I can't get that last setting to work in LW 2019 . Same goes with animating the gravity to avoid having parts of the mesh moving too soon.
    Last edited by marchermitte; 12-31-2019 at 02:06 AM.

  4. #4
    Frequenter
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    I noticed you have a textured luminosity apllied to at least some of you surfaces. Have you tried to deactivate that and setting luminositry to zero, and checked if that will make a difference?

    What a about the colourspace of you transparency image? What is that set to?

    And if you use the colourpicker when checking the image in the display window, is there a fullblown white/black where you need it? Maybe, as Prom already suggested, your transparency white is not really pure white?

  5. #5
    clip map is strictly zero or one (off or on) you put a progressive gradient in there that is what you get, you need to use the transparency channel instead, and don't forget to deal with the specular and reflective channels if you do because they will still be working even when transparent

  6. #6
    RETROGRADER prometheus's Avatar
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    Quote Originally Posted by marchermitte View Post
    By clip I mean a video clip, not a clip map as I need progressive transparency in the smoke area. The problem comes from the transparency It self, clip works as expected (just not what I need in that example)
    Prometeus, while you're here, I was trying to find one of your post, some earthquake example, where you put the classic gradient based on a null distance to control the glue amount of the bullet simulation. The other setting was, if I remember correctly, a gradient (based on the distance from a null as well) in the density channel. I can't get that last setting to work in LW 2019 . Same goes with animating the gravity to avoid having parts of the mesh moving too soon.
    Yes, I understood that before about the clip map being a video, and that is what I used in transparency and luminosity channels as well, I tested a mp4 file of smoke from youtube, and it worked flawlessly on a simple plate, but I mentioned clip map since you have the texture button for the clip map highlighted..and by that I assumed you had a clipm map there..which you really shouldnīt have to use if you want a smooth blend and not a sharp clip map cutoff.

    As for the earthquake post, I donīt know where it is, I would have to search for it in the forums..but I just got back home after a new years dinner at my sisters place, 2:18 hours in to the new year..so I am just gonna relax in front of some flick on the tv or so, will have to check later if I can find that thread, and it was a long time I since I fiddled with that, I donīt think I got the scene on this machine either..will have to look, or recreate.


    Happy New year to you all!

  7. #7
    RETROGRADER prometheus's Avatar
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    Quote Originally Posted by fishhead View Post
    I noticed you have a textured luminosity apllied to at least some of you surfaces. Have you tried to deactivate that and setting luminositry to zero, and checked if that will make a difference?

    What a about the colourspace of you transparency image? What is that set to?

    And if you use the colourpicker when checking the image in the display window, is there a fullblown white/black where you need it? Maybe, as Prom already suggested, your transparency white is not really pure white?
    Thatīs what I said

    - - - Updated - - -

    Quote Originally Posted by gerry_g View Post
    clip map is strictly zero or one (off or on) you put a progressive gradient in there that is what you get, you need to use the transparency channel instead, and don't forget to deal with the specular and reflective channels if you do because they will still be working even when transparent
    Thatīs what I said partly...just being obnoxius a couple of hours in the new Year, Happy New Year.

  8. #8
    Ok as every one has said above fine don't disagree, will try to make my self more clear, transparency only affects transparency, any other channel you have in play will require a similar mask, the one you have loaded in transparency needs to be loaded into luminosity, By the looks of it you already have as the T button is in play, unless you have a gradient in there, what needs to be there is a matching image sequence or video clip where the non cloud portion in completely black and set to alpha to knock out the luminosity.

  9. #9
    Hey, happy new year to you all, guys, you still keep answering at that moment of the year dedicated to party , family and friends, kudo to you all!
    Prometeus, I had the clip map highlighted because I had tried that to see if It changed anything (with the transparency channel active as well, to "cut out" the translucent problem from the polygon, but after I tried that, the image inside was turned off.
    No specular of reflection on that polygon, I also removed the glossy reflection option of course and removed the background option both in reflection and refraction settings.
    Also I noticed that the problem arises especial against the background as if the bakground image was "additively" mixing with the transparency. I'm going to make a video later to explain in a more detailed way what I mean. It seems to me that until LW 2018, the transparency wasn't behaving like that. I used to put fake clouds in the sky by just using polygons with an image and an alpha channel. I can't get It to work now.
    Last edited by marchermitte; 01-01-2020 at 09:02 AM.

  10. #10
    RETROGRADER prometheus's Avatar
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    Quote Originally Posted by gerry_g View Post
    Ok as every one has said above fine don't disagree, will try to make my self more clear, transparency only affects transparency, any other channel you have in play will require a similar mask, the one you have loaded in transparency needs to be loaded into luminosity, By the looks of it you already have as the T button is in play, unless you have a gradient in there, what needs to be there is a matching image sequence or video clip where the non cloud portion in completely black and set to alpha to knock out the luminosity.
    Yes..I should have been clear to that is what I use too, I said only transparency ..in reference to no clip map, but should have mentioned that the clip should be loaded in to the luminosity channel as well, and in the color channel if there is a color spectrum needed.

  11. #11
    RETROGRADER prometheus's Avatar
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    Quote Originally Posted by marchermitte View Post
    Hey, happy new year to you all, guys, you still keep answering at that moment of the year dedicated to party , family and friends, kudo to you all!
    Prometeus, I had the clip map highlighted because I had tried that to see if It changed anything (with the transparency channel active as well, to "cut out" the translucent problem from the polygon, but after I tried that, the image inside was turned off.
    No specular of reflection on that polygon, I also removed the glossy reflection option of course and removed the background option both in reflection and refraction settings.
    Also I noticed that the problem arises especial against the background as if the bakground image was "additively" mixing with the transparency. I'm going to make a video later to explain in a more detailed way what I mean. It seems to me that until LW 2018, the transparency wasn't behaving like that. I used to put fake clouds in the sky by just using polygons with an image and an alpha channel. I can't get It to work now.
    I have no issues on mapping a cloud image on to a polyplate..in LW 2019, in this case for this map from the net, it is inversed in the transparency channel, but not in the luminosity channel.



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  12. #12
    Now, that's very embarrassing... I found the problem, after trying just about everything, the refraction options in the surface panel was on raytraced only, not background + raytraced... so the backdrop image wouldn't show through the planes, only black of course. Sorry to bother you with such a trivial and basic matter. thank you all.

  13. #13
    RETROGRADER prometheus's Avatar
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    Quote Originally Posted by marchermitte View Post
    Now, that's very embarrassing... I found the problem, after trying just about everything, the refraction options in the surface panel was on raytraced only, not background + raytraced... so the backdrop image wouldn't show through the planes, only black of course. Sorry to bother you with such a trivial and basic matter. thank you all.
    Nothing to worry about, in fact...it is our duty to each other to mention All kinds of possibilities that could cause things not to work properly, glad to see it solved.

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