Is this a render bug?

Questions
1

Hi everyone,

Do you see this as well:

I would expect there to be a tiny red dot - probably only visible if you zoom in close enough to the center of the plane.

Did I mess something up with the buffer? But even then the pixel should just be somewhere else, shouldn’t it?

Best wishes
Joe

2

I can’t repro (I am on Firefox Win11):

What’s your browser and OS?

3

Originally tried with Firefox (latest) and Win 10.

Now, re-tried with Chrome. There it works.

Just to double check. I tried with Firefox again. Additionally, it just looked like this:

Screenshot 2025-06-12 143857
Screenshot 2025-06-12 1438571913×881 159 KB

wtf?? How could there possibly anything blue? Is my GPU dying (or dyeing)?

4

Update:

Ok, sorry for the red dot thing. It is just an illusion due to going beyond the camera near plane.

But the new blue thing:

Does anybody else see this?

5

Does it happen for small buffer sizes as well? The buffer might be too big. I can’t repro the blue shade as well :thinking:

yes :laughing:

6

I don’t see anything blue, firefox linux.

7

What are you trying to do?

From the PG you posted you filled the buffer with black then set the alpha to 255, then when scene was ready updated a single pixel on the buffer to red which was causing the red dot and what you were seeing is the interpolation.

Not to sure what you are trying to accomplish.

But also I do not see the blue you are seeing either.

8

I was going to file this as something wrong with my laptop. But this is awfully specific. To reproduce the blue issue:

  1. Open firefox
  2. Go to playground from above
  3. Notice it is not blue
  4. Tab away
  5. Close firefox (keep tab open; but not active)
  6. Open firefox again
  7. Open playground
  8. The blue issue occurs

But to fix it, it seems, you just have to run the playground again.

Ah, good catch! I have just tried with 64x64 texture (https://playground.babylonjs.com/#53XBC3#1) and I cannot reproduce anymore. But the moment I switch back to the 512x512, blue again.

Just a minimal reproduction of what I thought was (or is, idk) a bug.

9

Aha, we are making progress! What’s your GPU, maybe you are exceeding a buffer limit? Do you have any WebGL warnings? Maybe try to use WebGPU and see if it crashes :thinking:

10

No warning :frowning: Then I wanted to try WebGPU. But it was not available in Firefox (??). I then remember that I have a second Nvidia GPU (sorry :face_with_crossed_out_eyes:). While I still could not get WebGPU in Firefox, the bug disappeared!

The last thing I tried: with the Nvidia GPU, change texture size to 16Kx16K. No bug.

If you want me to try anything else, let me know. Otherwise I am filing this as related to me Intel GPU.

11

Yeah looks like an issue with your intel GPU. FYI WebGPU is enabled in Firefox Nightly :wink: