Corona image editor alpha channel

[pietro3d]

Hi, I'm using 3ds batch render that save me in CXR format (with lighter mixer). So when user corona image editor to edit lighting I can't save in TGA format to have alpha channel. Also used PNG format but there isn't alpha. What's the right way to save alpha channel in cxr format?

[Tiago4D]

yes

I can´t save png or exr files with alpha...

[Tanakov]

I think I had this problem, just try adding the "Alpha" render element and have it separate

[maru]

I think this (or similar) issue has been already discussed here:
https://forum.corona-renderer.com/index.php/topic,16497.msg104599.html#msg104599

As instructed in the thread, could you try the newest daily build, and see if there is an improvement in alpha channel behavior for you?
Here is how to get it: https://coronarenderer.freshdesk.com/support/solutions/articles/5000570015-daily-builds
Remember to backup any important scenes before opening in DBs!

[aaouviz]

I'm getting this unexpected behaviour now too...

I did a batch render saved to *.CXR and now I cant save out the images from Corona Image Editor to PNG with no background. What's the deal? Is this expected? What can I do to be able to save the PNG with no background?

I'm using the latest daily build Sep 14.

[maru]

Are you sure that this is not just a matter of the software you are using to open your png files? See this post: https://forum.corona-renderer.com/index.php?topic=16428.msg133462#msg133462

[aaouviz]

Are you sure that this is not just a matter of the software you are using to open your png files? See this post: https://forum.corona-renderer.com/index.php?topic=16428.msg133462#msg133462

I'm fairly sure. I regularly save out from the VFB (in 3dsmax) to *.png and open in Photoshop. I'm doing the exact same procedures but from Corona Image Editor and getting solid backgrounds.

(An odd sign is that when I open the *.png files in Photoshop, usually it is listed in the layer manager as a layer (unlocked) by default, but these images are opening in PS with the locked "background" layer automatically...)

What am I missing??? Am I meant to add alpha channel to the render elements or something obvious like this? I find this all very strange. I'll happily share the *.cxr file if you'd like?

EDIT: I should note: I can save out the PNG as desired (ie; no background) ONLY when I'm saving out from the 'Beauty' pass. If I've done some work in the LightMix (which automatically switches the selected/visible pass in the dropdown menu to 'LightMix Interactive') and save it out from there, that's when the problem occurs. Am I to presume from this that I cannot edit the lightmix and still save out to PNG with no background? Or this is a potential bug?

[aaouviz]

No news on this?

[louisryko]

I have the same issue... very odd!

A workaround would be handy to know :)

[maru]

Sorry for the delay, we will look into this.

[louisryko]

Hi,

This is still an issue with me... I am crazy or should it not work like this?

Any updates?

[burnin]

Alpha comes out of CFB as it should using .exr format.

PS
i don't use, so i haven't tested other formats

[maru]

Here is what I tested in Corona Renderer 3 and CIE 3:

-Set up a simple scene with LightMix in 3ds Max
-Renderer to .cxr format from 3ds Max directly (Render Setup > set output path > Render with pass limit)
-Opened the resulting files in CIE
-Used "Save all" option > saved to EXR and PNG
-Inspected in Photoshop: all files have alpha channel (transparency)

-Back to Max
-Set up Batch rendering with 2 cameras, with output set to CXR
-Opened the resulting files in CIE
-Used "Save all" option > saved to EXR and PNG
-Inspected in Photoshop: all files have alpha channel (transparency)

I am not able to reproduce this problem.
If anyone is, please explain how exactly to proceed.

[aaouviz]

Thanks for the reply and effort Maru,

I didn't fully follow your steps as I perhaps I didn't explain myself properly...

The issue arises when I edit the lighting (in CIE) and save it out. So generally speaking, saving a PNG from CIE and opening it in Photoshop works all well - that is to say, the transparent background works as expected.

The problem happens when I edit the lighting (with LightMix in CIE) and save as PNG afterwards. In this instance the background is solid, even when saved as PNG.

If this is still somehow confusing I'll happily make a screen capture of my process and share it....

[maru]

Thanks! It should be clear now (I probably overlooked some stuff). I'll try again.