VR BUG: Material Sprites from transparent PNG files are visible only in left eye

I found a bug in 4.14 - 24 bit PNG files exported from Adobe Photoshop CC are visible in one eye (left), but not the other when used as a Material Billboard.

I’ve tested it it on HTC .

Issue seems to be specifically with textures that use an alpha channel and are exported from Adobe Photoshop CC (I use version 2017.0.0) through “save for web” with PNG-24 preset.

While trying to debug it I tried to use “UE4_Mannequin_MAT_MASKA” texture from the VR Template, linking Blue as an Opacity channel - everything worked fine. I also tried [this PNG from wikipedia][1] and it worked fine as well. Finally I tried 8-bit PNG file from Photoshop - and it also worked. Then I tested both: newly created files and reexported to PNG-24 - all caused the issue.

To make it easier, down below I attached one of my sample PNG textures that’s causing the issue (red X) .

Reproduce:

  1. Create new Actor Blueprint
  2. Add Material Billboard, open it
  3. Add Sprite
  4. Create a material from imported texture: PNG-24 file with transparency:

Here’s Material I used, though I noticed that blend mode makes no difference, I’ve tested it in Opaque, Masked and Translucent modes, issue occurred in all of them

116221-material.jpg

  1. Set new material to your Blueprint sprite
  2. Compile, save, close the blueprint
  3. Place blueprint in a level (I used MotionControllerMap from VR Template)
  4. Run VR Preview - billboard will be correctly displayed in the left eye, but not visible at all in right.

Hello MarcinW,

After doing some digging I found that this is a known issue and that it has been submitted to the developers for further consideration. I have provided a link to the public tracker. Please feel free to use the link provided for future updates.

Link: Unreal Engine Issues and Bug Tracker (UE-37611)

Make it a great day

Oh, awesome, great find! Thank you.

Sadly, the issue is now marked as won’t fix… any alternative way to make a billboard work in VR with instanced stereo? Apart from implementing a camera facing plane in blueprint?

If possible, try to use a Translucent material, rather than a Masked one.