Some models are not displayed in Chrome

[cx20]

I tried the PBR model sample with several browsers.
Windows 10 + Intel HD Graphics 520 + Chrome 58
Windows 10 + Intel HD Graphics 520 + Firefox 53
Windows 10 + Intel HD Graphics 520 + Edge 14

Models	Chrome 58	Firefox 53	Edge 14
MetalRoughSpheres	✅	❌	❌
AppleTree	❌	❌	❌
Avocado	✅	❌	❌
BarramundiFish	✅	❌	❌
BoomBox	✅	❌	❌
Corset	✅	❌	❌
FarmLandDiorama	❌	❌	❌
NormalTangentTest	✅	❌	❌
Telephone	✅	❌	❌
Triangle	❌	❌	❌
WaterBottle	✅	❌	❌

Most models are displayed in Chrome, but some models are not displayed. AppleTree, FarmLandDiorama and Triangle.
Firefox and Edge can not display because EXT_sRGB WebGL extension is not supported.

[cx20]

AppleTree and FarmLandDiorama will print the following errors on the console.

[.Offscreen-For-WebGL-0000016CDFD27880]GL ERROR :GL_INVALID_OPERATION : glDrawElements: attempt to access out of range vertices in attribute 0

Triangle will output the following error to the console.

scene.js:123
Uncaught TypeError: Cannot read property 'doubleSided' of undefined
    at Mesh.drawMesh (scene.js:123)
    at drawNodeRecursive (scene.js:348)
    at Scene.drawScene (scene.js:360)
    at Mesh.initBuffers (scene.js:217)
    at FileReader.reader.onload (scene.js:408)

[emackey]

@cx20 I patched an issue that should get many of the models working in Firefox and Edge.

[cx20]

I confirmed that the patch is functioning.

Models	Chrome 58	Firefox 53	Edge 14
MetalRoughSpheres	✅	✅	✅
AppleTree	❌	❌	❌
Avocado	✅	✅	✅
BarramundiFish	✅	✅	✅
BoomBox	✅	✅	✅
Corset	✅	✅	✅
FarmLandDiorama	❌	❌	❌
NormalTangentTest	✅	✅	✅
Telephone	✅	✅	✅
Triangle	❌	❌	❌
WaterBottle	✅	✅	✅

[cx20]

I confirmed that it is displayed by dragging and dropping the following model to the glTF Reference Viewer.

Models	Chrome 70	Firefox 63	Edge 18
MetalRoughSpheres	✅	✅	✅
AppleTree	✅	✅	✅
Avocado	✅	✅	✅
BarramundiFish	✅	✅	✅
BoomBox	✅	✅	✅
Corset	✅	✅	✅
FarmLandDiorama	✅	✅	✅
NormalTangentTest	✅	✅	✅
Telephone	✅	✅	✅
Triangle	✅	✅	✅
WaterBottle	✅	✅	✅

I think that Issue can be closed.

[emackey]

Thanks @cx20!