[WebGL2] "3D Material Testers" doesn't load textures properly and takes 24minutes to load

[37TS]

Godot version:
Godot_v3.0.3-rc2_win64 (with rc1 export templates because rc2 templates for html5 are missing, though the same happens with Godot_v3.0.3-rc1_win64 too)

OS/device including version:
Win10 x64 / R9 280X / Firefox 60.0.1 (64-bit)

Issue description:
Multiple errors in the web console when exporting the demo project "3d material testers".
Of particular importance the last "pieces" regarding WebGL warning: blitFramebuffer: DRAW_FRAMEBUFFER: This operation requires zeroing texture data. This is slow.

Up to now, I'm trying all the offical projects given as demos on the website.
My (disputable) analysis is that there is some procedure slowing down the loading times, maybe timing out the GPU.
I had to suppress errors generated from the material%20testers.html and this prompted the webconsole to output errors as related to the material%20testers.js file generated during export (nothing special here, it just changes the origin of the error in the console but it is really the JS the one responsible, not the html).

All in all, the project works perfectly at 60fps but some textures are missing and it takes approximately 104 to 112 kilobytes per second to load when exported as release, or about 23 minutes for 140 megabytes (it takes 24 minutes if exported as "debug"). This seems to be related to an indefinite amount of exceptions/errors raised in the background and to some wrong procedures used by the engine because I've tried bigger WASM projects made with other engines and they're incredibly fast in loading times ( to make it clear, It can't be my setup).

Also, while searching for issues, I've found somebody who archived ** ERROR: Method/Function Failed, returning: RES() -projectname- :whatever-line:whatever-column
At: core/io/resource_loader.cpp:186:_load()** by saying that it was strictly mono related : it isn't.

I've attached some screen-shots (one for each cube-map) to prove that the demo is indeed loading but that some textures are missing.

Here's the list of errors
( the last errors appear whenever you scroll in the html page)

---

3d_material_testers_errors.txt

---

Steps to reproduce:

• Export the demo "3D material testers" as HTML5 project
• Do not select a texture compression out of the 3 available because you'll have more errors (s3, etc, etc2)
• Load it in the Firefox (chrome might not prompt some errors, nonetheless, it is as slow as firefox)

Minimal reproduction project:
Not needed. It's the official, unmodified demo.

[37TS]

UPDATE:

There is something worth checking here for "Buffer for uniform block is smaller than UNIFORM_BLOCK_DATA_SIZE"

https://github.com/mozilla/gecko-dev/blob/master/dom/canvas/WebGLContextDraw.cpp

// Check UBO sizes.

        for (const auto& cur : linkInfo->uniformBlocks) {
            const auto& dataSize = cur->mDataSize;
            const auto& binding = cur->mBinding;
            if (!binding) {
                mWebGL->ErrorInvalidOperation("%s: Buffer for uniform block is null.",
                                              funcName);
                *out_error = true;
                return;
            }

            const auto availByteCount = binding->ByteCount();
            if (dataSize > availByteCount) {
                mWebGL->ErrorInvalidOperation("%s: Buffer for uniform block is smaller"
                                              " than UNIFORM_BLOCK_DATA_SIZE.",
                                              funcName);
                *out_error = true;
                return;
            }

            if (binding->mBufferBinding->IsBoundForTF()) {
                mWebGL->ErrorInvalidOperation("%s: Buffer for uniform block is bound or"
                                              " in use for transform feedback.",
                                              funcName);
                *out_error = true;
                return;
            }
        }

        ////

[eon-s]

try to hide long blocks of text in

<details>

</details>

tags to make posts more readable.

[37TS]

@eon-s fixed.

[akien-mga]

CC @eska014

[LinuxUserGD]

For me it only takes 1 minute but I get strange rendering glitches. I've picked all checkboxes.

That you don't get textures when you uncheck all checkboxes is expected, I think. I also got no textures by unchecking everything on my Solus Stunts project.

[clayjohn]

We are no longer working on the WebGL2 backend due to poor driver support on most systems. We recommend you use the GLES2/WebGL backend instead.

Unfortunately, that means this bug just isn't going to be fixed in GLES3/WebGL2, sorry.