Models with blend shape are not rendered correctly on Android

[xhk1992]

Godot version: Godot Engine v3.2.1.stable

OS/device including version: OnePlus G1910 GPU:Adreno(TM) 640 GLES3

Issue description:

I created a test scene

1. head model with about 50+ blend shapes
   

2. cube model with 2 simple blend shapes
   

On my PC(OpenGL ES 3.0 Renderer: Intel(R) UHD Graphics 620）

It looks like this

But on my android phone ,it looks like this

I can't capture any useful logs on my phone

And this is my phone info in OpenGl ES CapsViewer

http://opengles.gpuinfo.org/displayreport.php?id=4388

Steps to reproduce:

1. open project
2. export android apk
3. run

I tested on 3 different phones, and each phone had rendering issues.

Minimal reproduction project:
I compressed with 7z and changed the suffix to zip
3D_Android_model.zip

[Calinou]

Note that the current GLES3 renderer is expected to have trouble on most Android devices.

[shudaxia]

I had the same problem with my XIAOMI 8 phone. It seems that godot-3.2.1 doesn‘t support the FBX model with blender shape well on the android side but not on the Windows side. So who can tell me what to do next...

[xhk1992]

Note that the current GLES3 renderer is expected to have trouble on most Android devices.

If I want to modify the engine source code, are there any suggestions?

[Calinou]

@xhk1992 There really isn't anything simple that can be done about it. The GLES3 renderer is a high-end renderer, and as such, expects a fully compliant implementation. Unfortunately, mobile devices often have bugs in their GLES3 drivers.

The GLES2 renderer doesn't support blend shapes: #37804

[xhk1992]

@xhk1992 There really isn't anything simple that can be done about it. The GLES3 renderer is a high-end renderer, and as such, expects a fully compliant implementation. Unfortunately, mobile devices often have bugs in their GLES3 drivers.

The GLES2 renderer doesn't support blend shapes: #37804

Okay, I still want to try it myself. And I hope this problem will be solved in version 4.0. thank you very much!

[nonunknown]

I can confirm something like in desktop version too:

The "?" crate is a base scene
The UpArrow crate is inherited from this crate

so they both has blend shapes, when its activated this bug happens

OS: Ubuntu 20.04
Godot: Stable 3.2 stable

[yakswa]

Some Android Sample using GLES30.GlGenTransformFeedbacks
glGenTransformFeedbacks
glBindTransformFeedback

but godot 3.4 doesn't have functions in glad and doesn't use it
how about using it

---

I am tested result is same
Hope try another way VTF or compute shader