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 Vive.

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.