MRT not supported on IOS?

[BMWPilote]

It seems that engine.getCaps().drawBuffersExtension returns false on IOS and so that the multi-renderTarget cannot work on IOS? I am really sad if so. Could anyone please confirm? Or did I miss something?

Thanks a lot.

[dbawel]

https://docs.microsoft.com/en-us/windows/uwp/app-resources/using-mrt-for-converted-desktop-apps-and-games

[Guest]

I confirm unfortunately

[dbawel]

@BMWPilote

I used this Github code when I had a similar issue:

https://github.com/BabylonJS/Babylon.js/blob/master/dist/previous releases/babylon.2.4.d.ts

Check lines 45, and 172. Worked on my Mac Pro ( with some modifications). Written by @Deltakosh - so I'm not certain why he doesn't believe it's possible. Of course, a modification of the code that actually runs is far more difficult to write. There are literally 100s of apps utilizing MRT for IOS - just do a search and get whatever code you need. I can't share what I did, as it is the property on Sony Electronics.

DB

[Guest]

Well I confirm that multi render target are not supported on iOS (I've just checked a few minutes ago to make sure iOS 11 did not change anything)

[dbawel]

@Deltakosh

This might help confirm my experience...

http://community.monogame.net/t/solved-ios-gles-3-0/9839/5

It's a frame buffer issue that can be worked around.

DB

[Guest]

Yep this is in opengl. Unfortunately they did not push the support on Webgl

[dbawel]

@Deltakosh

OK, another link I found useful...

https://www.khronos.org/webgl/public-mailing-list/public_webgl/1301/msg00055.php

But there's nothing simple about it - it's an OpenGL port no matter what - but it can be done. At least we did this at Sony... as a team of course.

DB

[dbawel]

In WebGL, it's not simple at all, but you can disable Z-buffering, and build your own Z-buffer functions. This will work, but again is quite an advanced solution to write. Perhaps new Z-buffering computations could be written into babylon.js? Of course, by far more talented devs than myself. @Deltakosh? I know you have a fantastic team!

DB

Edit - I had this in my bookmarks, and realize now that the links are outdated. Still, I'd love to see the changes made to the Z-buffer computations to permit MRT.

[dbawel]

This being done, but every link I find uses a fragment shader. Here's a useful link:

https://webglfundamentals.org/webgl/lessons/webgl-drawing-multiple-things.html

and

https://webglstats.com/webgl/extension/WEBGL_draw_buffers

But it looks as though we'll be waiting for WebGL 2.0 - although I personally believe we will still be waiting before this is standard.

And now I will avoid this topic, as I must refer to @Deltakosh . If anyone knows more about this than him, then I a rubber ducky...?

DB

[Guest]

We do have complete support for MRT even in webgl1 if the draw buffers extension is here. This is how this demo is done: https://www.babylonjs-playground.com/#7D2QDD#0

But to refer to OP question: this does not work on iOS because the draw buffer extension is not present

[BMWPilote]

11 hours ago, Deltakosh said:

We do have complete support for MRT even in webgl1 if the draw buffers extension is here. This is how this demo is done: https://www.babylonjs-playground.com/#7D2QDD#0

But to refer to OP question: this does not work on iOS because the draw buffer extension is not present

Thanks you for your confirmation boss.

[BMWPilote]

11 hours ago, Deltakosh said:

We do have complete support for MRT even in webgl1 if the draw buffers extension is here. This is how this demo is done: https://www.babylonjs-playground.com/#7D2QDD#0

But to refer to OP question: this does not work on iOS because the draw buffer extension is not present

Thanks you for your confirmation boss.

[dbawel]

Again, this can be accomplish by using a shader. However, it's not for the novice, however the shaders already exist. But again, I'll aways defer to @Deltakosh since he is my good friend, and mentor; and an excellent dev and person. I just hope we can get together soon to simply have a beer...?

DB