Autodesk forge viewer in headless chrome, CONTEXT_LOST_WEBGL

Question

I'm trying to use headless Chrome (v66 on Win10, using C#) to take a series of screenshots from a 3D model in forge autodesk viewer.

The problem i'm facing is that once the model is loaded i set the camera into the first position, take a screenshot and then try to set the camera to the next position for the next screenshot. Once i try that (setting the camera position later then on the initial load), the webgl context is lost.

I have too little knowledge of WebGL / swiftshaders / etc, but what i find frustrating, is that when i position the camera directly after the load, it does work. (IE, the workaround is to spawn a seperate headless session per camera view, but since the loading of the geometry takes 20sec or more, thats not preferred)

So, this:

viewerApp.myCurrentViewer.addEventListener(Autodesk.Viewing.GEOMETRY_LOADED_EVENT,
function () {
    _viewer = viewerApp.myCurrentViewer;
    SetPerspective();
    SetCamera(cams[0].position, cams[0].target);//no probs here
    document.getElementById('MyViewerDiv').classList.add("geometry-loaded");       
 });

works (the camera is positioned), but when i execute a javascript function later (using driver.ExecuteScript($"SetCamera({JsonConvert.SerializeObject(target.Value.Position)},{JsonConvert.SerializeObject(target.Value.Target)});"); or on a timeout in the page itself, it outputs WebGL: CONTEXT_LOST_WEBGL: loseContext: context lost.

When i use a smaller model, everything works. Thus i think i understand the reason is too much memory/processing consumption, but why is it working at all then?

Looking at resource monitor, im not convinced that the consumption is actually problematic, my laptop should be capable (i7HQ7700, gtx1050, 16gbRam) I tried fiddling around with some GPU and GL flags of Chrome, to no avail. I suspect the GPU isn't used (which i found some posts that it actually can be used in headless...) Also, the forge viewer outputs GPU mem used, but that might be just the log message:

Starting ChromeDriver 2.38.552522 (437e6fbedfa8762dec75e2c5b3ddb86763dc9dcb) on port 62676
Only local connections are allowed.
[0517/203535.902:ERROR:gpu_process_transport_factory.cc(1007)] Lost UI shared context.

DevTools listening on ws://127.0.0.1:12556/devtools/browser/5b66c120-dc64-4211-a207-ac97152ace9a
---some ssl future warnings---
[0517/203540.524:INFO:CONSOLE(2)] "THREE.WebGLRenderer", source: https://developer.api.autodesk.com/modelderivative/v2/viewers/three.min.js (2)
[0517/203543.074:INFO:CONSOLE(0)] "[.Offscreen-For-WebGL-00000237DECBB270]RENDER WARNING: there is no texture bound to the unit 0", source: http://localhost:8881/Content/Screenshot.html
[0517/203543.074:INFO:CONSOLE(0)] "[.Offscreen-For-WebGL-00000237DECBB270]RENDER WARNING: there is no texture bound to the unit 0", source: http://localhost:8881/Content/Screenshot.html
[0517/203552.280:INFO:CONSOLE(2)] "Total geometry size: 8.434013366699219 MB", source: https://developer.api.autodesk.com/modelderivative/v2/viewers/three.min.js (2)
[0517/203552.281:INFO:CONSOLE(2)] "Number of meshes: 2909", source: https://developer.api.autodesk.com/modelderivative/v2/viewers/three.min.js (2)
[0517/203552.281:INFO:CONSOLE(2)] "Num Meshes on GPU: 2908", source: https://developer.api.autodesk.com/modelderivative/v2/viewers/three.min.js (2)
[0517/203552.281:INFO:CONSOLE(2)] "Net GPU geom memory used: 7494392", source: https://developer.api.autodesk.com/modelderivative/v2/viewers/three.min.js (2)
[0517/203558.143:INFO:CONSOLE(0)] "WebGL: CONTEXT_LOST_WEBGL: loseContext: context lost", source: http://localhost:8881/Content/Screenshot.html

To be complete, running the same program without the --headless flag, is working fine, so i guess the code itself is ok.

Is there any way to increase the allowed resources or anything?

(code for SetCamera)

        function SetCamera(newPos, newTarget) {
        nav = nav || viewerApp.myCurrentViewer.navigation;

        nav.setPosition(newPos);
        nav.setTarget(newTarget);
        nav.orientCameraUp();
    }

EDIT: Test case (currently on a test website, so this will we deleted at some point)

EDIT2: Result for running code below

NodeJS:

try {

    const URN = '';
    const Token = '';

    (async () => {
        const puppeteer = require('puppeteer');
        const browser = await puppeteer.launch();
        const page = await browser.newPage();
        console.log('browsing');

        await page.goto('https://rogerintelligentcloud.azurewebsites.net/test?urn=' + URN + '&token=' + Token);
        //replace autodeskURN and token to point to your model

        console.log("waiting");
        await page.mainFrame().waitForSelector(
            '.geometry-loaded', {
                timeout: 60000
            });

        await takescreen(page, 'nodetest1');
        await takescreen(page, 'nodetest2');
        await takescreen(page, 'nodetest3');
        await takescreen(page, 'nodetest4');
        await takescreen(page, 'nodetest5');
        await takescreen(page, 'nodetest6');    

        await page.evaluate("Test();");

        await takescreen(page, 'nodetest11');
        await takescreen(page, 'nodetest12');
        await takescreen(page, 'nodetest13');
        await takescreen(page, 'nodetest14');
        await takescreen(page, 'nodetest15');
        await takescreen(page, 'nodetest16');        

        await browser.close();
    })();
} catch (e) {
    console.log(e);
}

async function takescreen(page, name){
    await page.screenshot({
        path: 'c:\\temp\\'+name+'.png'
    });
}

Answer 1

I didn't see any WebGL related error messages show up with your snippet and the rme_advanced_sample_project.rvt model, the only one I can see is page.delay is not defined. Here is my test code modified from the your code snippet and Philippe's forge-viewer-headless demo. If I missed something, please kindly point out. Thanks~

import puppeteer from 'puppeteer'
import 'babel-polyfill'
import path from 'path'
import os from 'os';

try {
    const URN = 'YOUR_URN';
    const Token = 'YOUR_TOKEN';

    (async () => {
        const browser = await puppeteer.launch();
        const page = await browser.newPage();
        await page.goto(`https://rogerintelligentcloud.azurewebsites.net/test?urn=${ URN }&token=${ Token }`);
    //replace autodeskURN and token to point to your model

        await page.mainFrame().waitForSelector(
            '.geometry-loaded', {
                timeout: 60000
            });

        await delay(3000);

        await page.screenshot({
          path: path.join( os.tmpdir(), 'nodetest.png' )
        })


        await page.evaluate("Test();");
        await page.evaluate("Test();");
        await page.evaluate("Test();");
        await page.evaluate("Test();");

        await delay(3000);

        const targetTxt = await page.evaluate(() => document.querySelector('body > :last-child').innerText );
        console.log( targetTxt );

        const targetLen = await page.evaluate(() => document.querySelectorAll('body > div:not(.box)').length );
        console.log( targetLen );

        await page.screenshot({
          path: path.join( os.tmpdir(), 'nodetest2.png' )
        })

        await browser.close();
    })();

    function delay(timeout) {
        return new Promise((resolve) => {
            setTimeout(resolve, timeout);
        });
    }
}
catch (e) {
    console.log(e);
}

Snapshot from my test result:

1. nodetest.png:

2. nodetest2.png:

Edit 2:

Tested with your code, it works fine on my machine.

But there is one change to run your code properly in my env. I modified your takescreen function definition:

function takescreen(page, name){
    return page.screenshot({
        path: 'c:\\temp\\'+name+'.png'
    });
}