OES_texture_float in WebGL on Mobile

2
votes

I made deferred shading renderer in WebGL using OES_texture_float texture to store G-buffer data.

This feature clearly works in browsers of PC(Chrome,Firefox,Safari,Edge...) But, this G-buffer seems not working in Mobile browser.

I tried to find out the reason, but I couldn't make it. This is how I did for debugging this.

  • Check OES_texture_float supported or NOT.

Of course I did this. And I made sure my devices for debugging is supporting OES_texture_float. I tried to getExtension and that method didn't return undefined.

And I also checked out the website for check WebGL extension compatibility(http://renderingpipeline.com/webgl-extension-viewer/).

  • I tried to fetch the pixels of the floating value texture with readPixels

I couldn't do this for mobile browser. But,in the Chrome in PC, readPixels to read floating value texture works correctly.

I guess readPixels to these types of texture is not ensured to work even if OES_texture_float was supported.

I know this is very hard to answer, but I couldn't paste my code here since these are very huge. And now I guess OES_texture_float is just supporting fetching texture value from texture liketexture2D(floatingTexture,uv) and not made sure to use for rendering the texture itself.

I want any suggestion to debug. And, if you know any sample using floating value texture and working in mobile, please paste the url to work. I want to inspect it.

1
opengl-eswebglopengl-es-2.0
Oh I didn't write what devices I used to debug on mobile. I used iPhone6SPlus and ASUS zenfone(I don't remember version number of zenfone.). – kyasbal
Do you get any warnings in the console using remote debugging ? Afaik you should be able to readPixels of floating point textures if they're supported, however you should check and enable the WEBGL_color_buffer_float extension if you're rendering to a floating point texture. See the last point in the Overview section of the extension spec. – LJᛃ
Checkout this answer stackoverflow.com/a/31974179/4168648. Also you may be able to workaround the problem by avoiding floats in your G-buffer. There are various packing strategies available depending on what you want to store in the G-buffer. Also check if your device supports MRT. If MRT is not supported then the chance of drawing floats are ~0%. – WacławJasper
Oh, I didn't know there was such another extension WEBGL_color_buffer_float. I wonder this is the reason.... – kyasbal

1 Answers

4
votes

Did you check that you can render to a floating point texture? I don't think you can in mobile.

After you create your framebuffer with a floating point texture attached are you calling gl.checkFramebufferStatus and checking that the results is gl.FRAMEBUFFER_COMPLETE? If it's not complete then the hardware does not support rendering to a floating point texture.