Use ktx2 texture without workers

Questions
1

I am trying to use a ktx2 texture without using web workers (I need to run it on a scope where is not possible to use them). For doing it I am setting:

BABYLON.KhronosTextureContainer2.DefaultNumWorkers = 0;

But then I am getting an error (on version 4.2.0) or a warning (version 5.0.0-alpha.42) saying “KTX2DECODER is not defined”

I created a simple playground to show the issue Babylon.js Playground

I am missing something? or is there something else I need to configure in order to use the ktx2 without workers?

Thank you

2

The playground doesn’t load the ktx loader (@Deltakosh - want to add that to the playground?)

However, even when including it there seems to be an issue - ktx2 without workers | Babylon.js Playground (babylonjs.com). @Evgeni_Popov , i noticed you did some work with the ktx loader, do you have an idea what’s happening there?

3

Yes!

1 Like
4

The playground is loading on demand, we should not change this part :slight_smile: https://playground.babylonjs.com/#EIJH8L#36

The issue might be with the file itself, @Evgeni_Popov will have a look on Monday :slight_smile:

1 Like
5

Scratch my previous answer, It is a bug when not using worker where we are not loading the lib dynamically :slight_smile:

I will try to make a fix soon.

6

Nightly will be up in one hour with the fix in :slight_smile:

7

For reference and review from @Evgeni_Popov on Tuesday :slight_smile: https://github.com/BabylonJS/Babylon.js/pull/11003/commits/dfd62b41356864117d3ae1d69866d9472721d6b7

8

Thanks @sebavan.

I had assumed that in the case of using ktx2 without worker threads, the user would load the required modules themselves.

9

np now it handles the three cases :wink:

2 Likes
10

Thanks a lot!!

11

Sorry to reopen this but we didn’t manage to make it work… and somehow looking at the khronosTextureContainer2.js code I see:

if (numWorkers === void 0) { numWorkers = KhronosTextureContainer2.DefaultNumWorkers; }

does this mean that is not possible to load ktx2 textures without a worker as when setting it to 0 will use the default number?

12

The line means if numWorkers is undefined (void 0 === undefined) we set it to BABYLON.KhronosTextureContainer2.DefaultNumWorkers;

By setting BABYLON.KhronosTextureContainer2.DefaultNumWorkers = 0; at the start of your program you should not get any worker thread created.

13

Oh ok! then I might be doing something else wrong…
We are using tree shaking so we don’t have the BABYLON.KhronosTextureContainer2 available so to set it I am importing:

import * as BABYLON from "@babylonjs/core/Legacy/legacy";

and then setting:

BABYLON.KhronosTextureContainer2.DefaultNumWorkers = 0;

But then it continues to fail to load the textures with the error Failed to load KTX2 texture data: KTX2DECODER is not defined.

Screenshot 2022-05-06 at 16.27.10

The texture is loaded via new Texture(textureName, scene); in case that is relevant.

Is there anything else we need to load or import for it to work? Thank you!

14

I’m not sure the “Legacy” pass should be used (but I have 0 knowledge about ES6)…

Doesn’t this import work?

import { KhronosTextureContainer2  } from "@babylonjs/core/Misc/khronosTextureContainer2";
15

I tried that as well with the same result… :confused:

Setting the DefaultNumWorkers is working as it then fails to load it (it loads correctly without setting the number of workers) but then I get this error about KTX2DECODER not being defined.

16

On the fix provided, there is this on the commit:

else if (typeof(KTX2DECODER) === "undefined") {
            KhronosTextureContainer2._NoWorkerPromise = Tools.LoadScriptAsync(KhronosTextureContainer2.URLConfig.jsDecoderModule).then(() => {
                KTX2DECODER.MSCTranscoder.UseFromWorkerThread = false;
                KTX2DECODER.WASMMemoryManager.LoadBinariesFromCurrentThread = true;

                const urls = KhronosTextureContainer2.URLConfig;
                if (urls.wasmUASTCToASTC !== null) {
                    KTX2DECODER.LiteTranscoder_UASTC_ASTC.WasmModuleURL = urls.wasmUASTCToASTC;
                }
                if (urls.wasmUASTCToBC7 !== null) {
                    KTX2DECODER.LiteTranscoder_UASTC_BC7.WasmModuleURL = urls.wasmUASTCToBC7;
                }
                if (urls.wasmUASTCToRGBA_UNORM !== null) {
                    KTX2DECODER.LiteTranscoder_UASTC_RGBA_UNORM.WasmModuleURL = urls.wasmUASTCToRGBA_UNORM;
                }
                if (urls.wasmUASTCToRGBA_SRGB !== null) {
                    KTX2DECODER.LiteTranscoder_UASTC_RGBA_SRGB.WasmModuleURL = urls.wasmUASTCToRGBA_SRGB;
                }
                if (urls.jsMSCTranscoder !== null) {
                    KTX2DECODER.MSCTranscoder.JSModuleURL = urls.jsMSCTranscoder;
                }
                if (urls.wasmMSCTranscoder !== null) {
                    KTX2DECODER.MSCTranscoder.WasmModuleURL = urls.wasmMSCTranscoder;
                }
                if (urls.wasmZSTDDecoder !== null) {
                    KTX2DECODER.ZSTDDecoder.WasmModuleURL = urls.wasmZSTDDecoder;
                }
            });
        }

maybe I am missing something but if KTX2DECODER is undefined we cannot set “MSCTranscoder” on it or is it a global that would be set on loading the js decoder?

17

I am also seeing that there was recently a refactor to it which might have broke the previous fix… I’ll tell if I find something else Add and use AutoReleaseWorkerPool for auto cleanup (#12096) · BabylonJS/Babylon.js@b291839 · GitHub

18

cc @bghgary

20

The Tools.LoadScriptAsync call should have added the KTX2DECODER as a module into the global space.

@Joel_Corominas I’m not sure how to repro. The OP’s playground works with the latest code. What’s the repro?