Animated GIF aren't animated

[elcibi]

Hi and thanks for this wonderful job!

Unfortunately, I have found an issue with animated gif :

Describe the bug
When using an animated gif as "MovieTexture" an error occurs : "Error loading movie: http://.../fire.gif?_=1672934206216.006 error"
When used as ImageTexture, only the first frame of the gif is displayed without any animation.

To Reproduce
Use any animated gif as texture for MovieTexture (error, not displayed) or ImageTexture (no error, but no animation)

Shape {
  appearance Appearance {
    texture MovieTexture {
      url "transparent-flame-video-5.gif"
    }
  }
  geometry Box {
    size .8 1.5 .001
  }
}

Expected behavior
Animated gif should be displayed and animated as movies, but with the benefit of the gif transparency
eg. https://jsl-online.com/wp-content/uploads/2019/07/transparent-flame-video-5.gif
This animated fire gif applied to a box shape should be transparent and animated :)

[create3000]

I spend some hours on this issue, now it's finally done. ;) Now, you can use GIFs with MovieTexture. Because it is hard to determine if the GIF is transparent, you must do it manually by setting Appearance.alphaMode to "BLEND" as shown below. Please test the new MovieTexture, and drop me a line if it is working for you.

#X3D V4.0 utf8

PROFILE Interchange

Shape {
  appearance Appearance {
    alphaMode "BLEND"
    texture MovieTexture {
      loop TRUE
      url "transparent-flame-video-5.gif"
    }
  }
  geometry Box {
    size .8 1.5 .001
  }
}

[elcibi]

It works fine, many thanks for this fast enhancement! :)

I've encountered an issue with a two framed gif (light on/light off) which wasn't playing the animation, but simply added a third frame to it and it runs well. Transparency works fine with the alphaMode setting!

Great job! Thanks to you I can dust off some pretty old vrml scripts. You're my hero! :)

[create3000]

Have fixed frame number determination. Should work better now when GIF has only two frames.

[elcibi]

Works perfectly :)
Thanks a lot!