When I first tried exporting my model to OBJ, then importing it into another document, the alpha had a weird staircasing effect: enter image description here

I realized this is because it was still using the alpha from the png, but from the color input of the image, plus it it had set the color space to non-color https://i.imgur.com/A9rOTjk.png

So I made the alpha it's own png image with just black and white, and used that for the alpha, which made it import correctly: https://i.imgur.com/H32ZEnO.png

And it works when importing into a cycles view, but in eevee the transparency is still not visible : enter image description here

This happens until I go into the settings of the material, and change the "blend mode" from "opaque" to "alpha blend". This setting does not seem to get saved when I export the objs.

So my question is: Is there any way to fix this, or will people have to change that setting manually every time they import one of my objs into cycles?

  • 1
    $\begingroup$ obj is a very primitive and thereby universal format. You can't expect it to save Eevee specific settings. If at all possible use fbx, but it will also not save the alpha blended mode. You could argue that the importer would take care of that for you, but most programs stopped imporving their obj importer at some point, because it's more of a "hail Mary" format for when everything else fails. $\endgroup$ – Frederik Steinmetz Mar 24 at 19:10
  • $\begingroup$ For the staircase issue: non-color is correct in this case. As for the staircase issue, make sure your image alpha is set to premultiplied. $\endgroup$ – Frederik Steinmetz Mar 24 at 19:13
  • $\begingroup$ @FrederikSteinmetz is fbx as widely supported? or better somehow? I see OBJs more often $\endgroup$ – stackers Mar 24 at 19:22
  • $\begingroup$ Depends on the software. CAD won't often allow fbx, bc. it's overkill, as I said obj is simple, therefore easy to implement. Unity found a bug in their obj importer years ago and closed the issue with the comment: It's an inferior format, use fbx. FBX enables you to export shapekeys, armatures and a bunch of other stuff. There's rarely a case where one format is just plain better than another one. $\endgroup$ – Frederik Steinmetz Mar 24 at 19:33

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