Canvas Alpha Bug

christian_gschweng

Hello everyone. I was hoping to find some help on this issue, that keeps reoccuring on my renders and I couldn't find a thread, that covers exactly this issue.

When ever I render with canvases and turn on alpha, when opening the exr, it is first of all all chopped up, you only see some of the elements of the masked object and the puzzle parts are also offset vertically, making the whole mask useless. As far as I can tell, this seems to happen at a large resolution. My last time, this happened at 5000px on the long length.

Question is. Is there like a pixel limitation to render alpha masks with canvas or a fix to this, so I can render also in larger resolutions?

Richard Haseltine

Which application and version are you using to open the .exr files? Is there somewhere you can upload one for others to hae a look at?

christian_gschweng

Hello Richard,

thanks for getting back at this. 

I'm using Photoshop version 21.1.3 ( the newer versions seem to run more unstable on my machine). In addition, I seem to have two EXR importers, one must be the default one by Adobe, the other one was a third-party-plugin, though I have no idea which one photoshop uses when I drag & drop the exr files into the canvas.

I have also uploaded an exr with that bug into my google drive. Here is the link to it:
https://drive.google.com/file/d/16tAyxYatAYeu5V_aIFvbTxBrHKlMioRx/view?usp=sharing

Thank you for getting into this.

AgitatedRiot

Well, I know for sure the format. exr-IO allows Photoshop to create layers and is still a part of Openexr. Both are in Photoshop.\

Exr-IO free Photoshop OpenEXR plug-in | OpenEXR Free plugin for Adobe Photoshop

christian_gschweng

AgitatedRiot said:

Well, I know for sure the format. exr-IO allows Photoshop to create layers and is still a part of Openexr. Both are in Photoshop.\

Exr-IO free Photoshop OpenEXR plug-in | OpenEXR Free plugin for Adobe Photoshop

 

Thanks for your response. I already tried that plugin. As you can see in my screenshot in the previous message, I have that plugin, plus the default one installed. I think, the issue is, that photoshop doesn't know, which one to use or better said, I have to tell it not to use the default exr plug, but the EXR-IO one.

christian_gschweng

A few more things, I have tried in the meantime...

1. uninstalled the exr-io plugin and open the exr again with default exr importer. Got a prompt for how to handle alphas, either as transparency or as alpha channel. in both cases it look broken, but different to my bug experience.

2. installed exr-io, the bug looks the same as before. No prompts on import for further options. After restoring the prompt for import, several options still resulted the broken alpha.

Richard Haseltine

In Affinity Photo 2 it did have a more solid, though still not uniform, silhouette on a layer above the chopped up base layer.

christian_gschweng

Richard Haseltine said:

In Affinity Photo 2 it did have a more solid, though still not uniform, silhouette on a layer above the chopped up base layer.

Kinda the same, most likely, here, when I tried to open the EXR with IrfanView and export it as png. It's better, but has trouble with DOF blur of the mask.

christian_gschweng

I tried to open the EXR and from another rendering in Blender and also in another third party EXR viewer called Veneta. Both displayed the same error, that Photoshop also showed me. I'm getting the feeling, it is not the import plugin, that's causing the issue, but DAZ Studio. What's suprising about it is, that I only have this issue, when I try large renderings.