Add support for thin instances

[ryantrem]

Thin instances don't currently work in Babylon Native. On iOS, they cause a crash with this error and stack:

2020-09-16 09:30:50.430191-0700 Playground[2068:1101454] Compiler failed to build request
2020-09-16 09:30:50.430974-0700 Playground[2068:1101454] Compiler failed to build request
2020-09-16 09:30:50.431063-0700 Playground[2068:1101454] /Users/ryantremblay/Repos/BabylonReactNative/Modules/@babylonjs/react-native/submodules/BabylonNative/Dependencies/bgfx.cmake/bgfx/src/renderer_mtl.h (361): BGFX WARN newRenderPipelineStateWithDescriptor failed: Vertex attribute 10 is not defined in the vertex descriptor.

#3	0x00000001058ff8dc in bgfx::mtl::RenderCommandEncoder::setRenderPipelineState(id<MTLRenderPipelineState>) at /Users/ryantremblay/Repos/BabylonReactNative/Modules/@babylonjs/react-native/submodules/BabylonNative/Dependencies/bgfx.cmake/bgfx/src/renderer_mtl.h:451
#4	0x00000001058f8f14 in bgfx::mtl::RendererContextMtl::submit(bgfx::Frame*, bgfx::ClearQuad&, bgfx::TextVideoMemBlitter&) at /Users/ryantremblay/Repos/BabylonReactNative/Modules/@babylonjs/react-native/submodules/BabylonNative/Dependencies/bgfx.cmake/bgfx/src/renderer_mtl.mm:4455
#5	0x00000001058c7b24 in bgfx::Context::renderFrame(int) at /Users/ryantremblay/Repos/BabylonReactNative/Modules/@babylonjs/react-native/submodules/BabylonNative/Dependencies/bgfx.cmake/bgfx/src/bgfx.cpp:2347
#6	0x00000001058c775c in bgfx::Context::swap() at /Users/ryantremblay/Repos/BabylonReactNative/Modules/@babylonjs/react-native/submodules/BabylonNative/Dependencies/bgfx.cmake/bgfx/src/bgfx.cpp:2257
#7	0x00000001058c366c in bgfx::Context::frameNoRenderWait() at /Users/ryantremblay/Repos/BabylonReactNative/Modules/@babylonjs/react-native/submodules/BabylonNative/Dependencies/bgfx.cmake/bgfx/src/bgfx.cpp:2222
#8	0x00000001058c3968 in bgfx::Context::frame(bool) at /Users/ryantremblay/Repos/BabylonReactNative/Modules/@babylonjs/react-native/submodules/BabylonNative/Dependencies/bgfx.cmake/bgfx/src/bgfx.cpp:2213
#9	0x00000001058d10f0 in bgfx::frame(bool) at /Users/ryantremblay/Repos/BabylonReactNative/Modules/@babylonjs/react-native/submodules/BabylonNative/Dependencies/bgfx.cmake/bgfx/src/bgfx.cpp:3881
#10	0x00000001051f7e9c in Babylon::NativeEngine::EndFrame() at /Users/ryantremblay/Repos/BabylonReactNative/Modules/@babylonjs/react-native/submodules/BabylonNative/Plugins/NativeEngine/Source/NativeEngine.cpp:1675
#11	0x000000010523b614 in Babylon::NativeEngine::RequestAnimationFrame(Napi::CallbackInfo const&)::$_11::operator()(Napi::Env) const at /Users/ryantremblay/Repos/BabylonReactNative/Modules/@babylonjs/react-native/submodules/BabylonNative/Plugins/NativeEngine/Source/NativeEngine.cpp:747

[bghgary]

Instancing in general are not supported yet. It's encapsulated in this issue, though maybe we should break it apart so that it's more visible.

[ryantrem]

Hmm interesting, when I tried regular instances I didn't get any errors and the frame rate doubled, so I thought it was working. If it's not supported, then I'm not sure what's going on!

[bghgary]

It's possible that some of it is working. The main thing is here. It won't cause the app to not work, but it shouldn't be using instancing. It's possible that it's faster just from reusing other things on the Babylon.js side.

[ryantrem]

Here is a Playground with sample code for both regular and thin instances: https://playground.babylonjs.com/#c2ynt9#23

[CedricGuillemet]

I'm taking a look.

[bghgary]

@CedricGuillemet Please link the PR that fixed this.

[CedricGuillemet]

PR #990
And remaining option work : #992