Author Topic: Save out bloom&glare pass with transparent background  (Read 2332 times)

2022-11-16, 19:07:10
Reply #15

pokoy

  • Active Users
  • **
  • Posts: 1850
    • View Profile
There's no alpha for bloom and glare. Only alpha-less and add/screen blending in PS or elsewhere. The fact that bloom and glare is added on top is the only reason you are able to obtain a separate layer/file of it. It's just the way it is in all apps, any bloom/shine/glare is added on top in addition blending mode.

Even if there was you'd have to un-multiply the image based on alpha which mostly only compositing apps offer (certainly not Powerpoint, even PS can't do it).


2022-11-17, 10:03:11
Reply #16

maru

  • Corona Team
  • Active Users
  • ****
  • Posts: 12711
  • Marcin
    • View Profile
Do not use alpha channel or any kind of transparency at all. Your bloom and glare layer should be 100% solid.
Marcin Miodek | chaos-corona.com
3D Support Team Lead - Corona | contact us

2022-11-17, 11:01:37
Reply #17

philipbonum

  • Active Users
  • **
  • Posts: 73
    • View Profile
If the use case is a quick background change in Powerpoint - which I assume don't support blending modes - I would load the bloom and glare pass in Photoshop, add a blank mask to it, copy paste the image onto the mask. This creates a black and white version of the image as a mask to the layer. Effectively masking away all the black/grey pixels. Then save as png(with alpha) and load into Powerpoint.
I assume this would look ok-ish on top of whatever background you need in Powerpoint.

2022-11-17, 11:30:46
Reply #18

maru

  • Corona Team
  • Active Users
  • ****
  • Posts: 12711
  • Marcin
    • View Profile
I couldn't find a way to merge the bloom and glare layer onto a transparent layer with the Add operation (it would always render the background black, even when using the "Apply image" option), so the solution was (as usual) to use something else than Photoshop. Here is an example made with Fusion (it's free). You can then save this as a PNG or some other format and place it on top of the bloom and glare-less background, and it won't give you black fringes or anything like that.

...this was a part of Compositing in Powerpoint 101 course...
Marcin Miodek | chaos-corona.com
3D Support Team Lead - Corona | contact us

2022-11-17, 18:52:10
Reply #19

chocolatecookie

  • Active Users
  • **
  • Posts: 12
    • View Profile
thanks guys! I think that does the trick yeah. any chance this can be implemented inside corona? in the meantime I'll figure out the fusion workaround then

2022-11-18, 11:45:54
Reply #20

vemod

  • Active Users
  • **
  • Posts: 10
    • View Profile
Yes, correct application of bloom and glare requires add mode, but here's a work-around:

On the bloom and glare layer, select all and copy, then add a layer mask to that layer and paste what you have copied in to the layer mask.

apply the layer mask to the layer. then in the top menu choose layer>matting>remove black matte.






2022-11-18, 13:53:18
Reply #21

maru

  • Corona Team
  • Active Users
  • ****
  • Posts: 12711
  • Marcin
    • View Profile
Yes, correct application of bloom and glare requires add mode, but here's a work-around:

On the bloom and glare layer, select all and copy, then add a layer mask to that layer and paste what you have copied in to the layer mask.

apply the layer mask to the layer. then in the top menu choose layer>matting>remove black matte.

No idea how reliable this is, but at first glance seems to work fine, thanks for sharing!
Marcin Miodek | chaos-corona.com
3D Support Team Lead - Corona | contact us