GS handles 'Multiply' blend mode incorrectly.

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Comments

  • The_Gamesalad_GuruThe_Gamesalad_Guru Member Posts: 9,922
    edited February 2013
    @blackcloakGS that was awesome that you took sometime out of your busy day to post here!! I can't tell you how much that means to us!!! I hope you will encourage your other coworkers to take a little time every week to post on a topic they have experience in. We crave quality info regarding GS. We love the tool and want to use it to it's max ability. Thank you again! You're awesome!
  • BlackCloakGSBlackCloakGS Member, PRO Posts: 2,250
    edited February 2013
    Yes there is a way to make your transparent pixel transparent when using multiply. Make sure there RGB value is pure white. Since white is represented as 1 (OpenGL use a color scale from 0 to 1 where 0 is black and 1 is white) the blend equation will equal the destination color (the framebuffer). That is why a pure white actor will show up transparent when using multiply.
    Hope this helps
  • SocksSocks London, UK.Member Posts: 12,822
    edited February 2013
    Yes there is a way to make your transparent pixel transparent when using multiply. Make sure there RGB it pure white. Since white is represented as 1 the blend equation will equal the destination color (the frame buffer). That is why a pure white actor will show up transparent when using multiply.
    Hope this helps
    Have you actually read this thread ? ;)



    As has already been mentioned earlier in the thread - this workaround has it's limitations too - you lose control over actor transparency (for instance, fades are out of the question), it causes issues with antialiasing where edges align - and on a PC it doesn't work at all as white is rendered as black.
  • capitalcarnagecapitalcarnage Member Posts: 371
    Findus = LOL
  • JGary321JGary321 Member Posts: 1,246
    @blackcloakGS that was awesome that you took sometime out of your busy day to post here!! I can't tell you how much that means to us!!! I hope you will encourage your other coworkers to take a little time every week to post on a topic they have experience in. We crave quality info regarding GS. We love the tool and want to use it to it's max ability. Thank you again! You're awesome!
    +1
  • SocksSocks London, UK.Member Posts: 12,822
    Findus = LOL
    ;)
  • BlackCloakGSBlackCloakGS Member, PRO Posts: 2,250
    @FryingBaconStudios thank you for the kind words
  • PixelMetalPixelMetal Member Posts: 283


    Have you actually read this thread ? ;)

    As has already been mentioned earlier in the thread - this workaround has it's limitations too - you lose control over actor transparency (for instance, fades are out of the question), it causes issues with antialiasing where edges align - and on a PC it doesn't work at all as white is rendered as black.
    @BlackCloakGS
    To expand upon this, NONE of the blending modes work right on Windows/Android. If I have, say, two actors set to use additive or multiply blending, and one of those actors changes transparency at any point (fading out/light flicker/etc.) then ALL actors with that blending mode in that scene will fade/flicker/etc.

    And: I wouldn't mind seeing Screen blending in their either, as that can be super-useful for graphical effects that don't require the blown-out look additive blending creates; considering Screen is the exact opposite of Multiply blending, it shouldn't be hard to get in there.

    And and: it's great to see an actual GS dev responding to stuff...I hope it becomes a more regular thing.
  • RPRP Member Posts: 1,990
    Oh my gawd!!! Now I know why elephants have long noses!!! Liars! The whole lot of 'em.
  • mataruamatarua Auckland, New ZealandMember Posts: 854
    edited December 2013
    Multiply this. Can you see me through this clear cling film @CodeWizard ?? Oh you can't even see me because it's black. You don't have the ability to see through this once transparent substance that was designed to be transparent so you could see things through it. So what use is black cling film? Well it doesn't have one does it? Where do you see black plastic? Rubbish bags. That is what this is - A BIG BAG OF RUBBISH.

    Double the images double the waste. Loss of function. Dumbfounded at this?

    Is this what openGL has left for us?

    Take the good with the bad I suppose >:)

    Dug this one up @Socks - sorry. :-O

    And just questionably justifiably exasperated. @-)

    M@
  • SocksSocks London, UK.Member Posts: 12,822
    @Matarua

    Yep, this issue still catches me out at least once a week, I'm so used to standard blending modes that I forget GameSalad's 'multiply' is screwy and you can't simply transfer work from Photoshop to GameSalad if you want to use 'multiply'.

    The response from GS says everything about GS being a group of (rather excellent) programmers providing a product to a group of designers. ;) One group can see that their shadows are screwing up on their animations while other group tells them this is how it should be. :))

  • mataruamatarua Auckland, New ZealandMember Posts: 854
    Black. It's the new clear.
  • mataruamatarua Auckland, New ZealandMember Posts: 854
    @Socks thanks for that cheap trick the other day - I think that is doing wonders for the little frame drops I was seeing at certain times on some devices.

    You are a legend sir, much appreciated! M@
  • mataruamatarua Auckland, New ZealandMember Posts: 854
    And do you know what sucks even more? I have blimmin black text on actors I want to do this with - gah - ~X(
  • mataruamatarua Auckland, New ZealandMember Posts: 854
    And then to top it all off the effect is not really realised and the aliasing shimmers as the camera scrolls and yada yada herp derp dingle dangle.

    :-<
  • SocksSocks London, UK.Member Posts: 12,822
    edited December 2013
    @matarua
    And then to top it all off the effect is not really realised and the aliasing shimmers as the camera scrolls and yada yada herp derp dingle dangle.

    :-<
    Yep, that's one thing that I couldn't work out a way around, all the suggested ways of working around the issue resulted in antialiasing problems on the edges of images.
    And do you know what sucks even more? I have blimmin black text on actors I want to do this with - gah - ~X(
    What exactly are you trying to achieve, there may be a way to work around this issue by preparing your images in Photoshop before importing into GS . . . ?
  • mataruamatarua Auckland, New ZealandMember Posts: 854
    edited December 2013
    @Socks I have it pretty sweet but in the essence of striving for ultimate perfection I thought I could use an image that is doubled up - one with multiply blending mode, the other with screen blending mode - this essentially creates an image very similar to a normal blending mode image but it is affected by the background and is in fact transparent without loosing anything - transparency reduces all areas of an image and it's colourspace as you know - so trying this solution to get these real world transparent but brilliant gems looking as real as possible that was my idea to bring this Photoshop experiment in to GameSalad - it failed miserably unfortunately.

    I also swap back and forward working on my different games so challenges are different but what happens is things I learn from one give me ideas for the other. That is where this has happened.

    I use GameSalad blending modes to excellent effect in my other game - thought I might take what I learned there and bring it across.

    Issue then was the game where blending works well is deep in space on black - the other is an illustrated, character filled uncanny valley landscape so the two can not be more different.

    But I have learn't a lot and when I got stuck with this problem this thread reared its ugly head and I had to re-ignite the fire that had me so burning with questions.

    Only OpenGL to blame.

    But was this in times when alpha channels were a step too far in blending modes?

    Cheers, M@
  • SocksSocks London, UK.Member Posts: 12,822
    Only OpenGL to blame.

    But was this in times when alpha channels were a step too far in blending modes?

    Cheers, M@

    I don't know enough to comment with any expertise, but in every single other piece of software these problems don't occur, you name it (Photoshop, AE, C4D, Shake, SumoPaint, Aperture, Adobe Flash . . . .etc) they all apply multiply identically - and unlike GS they honour the alpha channel regardless of image opacity.
  • mataruamatarua Auckland, New ZealandMember Posts: 854
    Only OpenGL to blame.

    But was this in times when alpha channels were a step too far in blending modes?

    Cheers, M@

    I don't know enough to comment with any expertise, but in every single other piece of software these problems don't occur, you name it (Photoshop, AE, C4D, Shake, SumoPaint, Aperture, Adobe Flash . . . .etc) they all apply multiply identically - and unlike GS they honour the alpha channel regardless of image opacity.
    Same here - after using photoshop since 1991 one year after it's Adobe release on an SE30 - well - things have changed since then - layers - png files - all mystery and magic back then. So in the tradition of evolution I say we do awesome with what we have got the best we can. Save the occasional outburst. 8-X
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