Concurrent CreateScreenshot Using RenderTargetAsync breaks rendering

Bugs
1

Engine: WebGL2
Version: 8.27.0
Playground: Babylon.js Playground

Steps to reproduce: Open the playground Babylon.js Playground

Expected: CreateScreenshotUsingRenderTargetAsync does not change rendering effect.

Actual:
It only renders a small area of the left-bottom corner

image
image764×666 7.83 KB

Possible fix:
Change engine.getRenderWidth = originalGetRenderWidth; to delete engine.getRenderWidth and the same height, but it generates typescript errors.
Reflect.deleteProperty(engine, 'getRenderWidth'); does not trigger ts error.
Or maybe override the getRenderWidth function only before scene.render.

And the function name seems too long for discourse

image
image770×194 4.83 KB

2

cc @sebavan, but I think it’s simply not supported because we change the state of the engine when we take the screenshot. You should just wait until the first screenshot is complete before taking the second one.

1 Like
3

Exactly this :slight_smile:

4

But I can’t find anywhere in docs states that, and users would assume there is no limit on concurrent usage by default

5

It’s an oversight in the doc:

1 Like
6

Hmmm, should all the screenshot functions share the same “mutex”, or should each one have their own?

7

They are all changing the state of the engine, which happens on the same thread (plus, I’m not sure there’s a need to concurrently run CreateScreenshot and CreateScreenshotUsingRenderTarget - the Async variants are really the same functions, only that they return a Promise).

1 Like