view3d.backgroundAlpha = 0.3 ;
but it`s still black without alpha ;why?

The same problem here. It was working before, but with latest releases of Flash Player and Away3D, it’s not working anymore.

Does anyone have a solution?

Thanks.

According to the page of AS3 reference referring to the Stage3D class:

The most distant are all StageVideo surfaces. Stage3D comes next, with traditional Flash display object content being rendered last, on top of all others. StageVideo and Stage3Dare rendered with no transparency. Player display object content is rendered with transparency.

I never used that parameter in Away3D, but according to the doc, in the current release of FP11 it is not possible to apply alpha to the Stage3D background.

Great answer. So they removed an interesting feature if you want to combine Stage3D and StageVideo (Like a remote Webcam behind a transparent background Away3D). I think it was in favor of performance.

I would use backgroundImage for webcam (it works for local one), but it doesn’t work if using Cumulus/OpenRTMFP, because pixel level is forbidden.

Now, my project is affected by this lack of feature.

Thanks for the answer.

It’s not as bad. You can always use the old Video class. It’s not a bad idea when you simultaneously use Stage3D as it otherwise could be GPU overwhelming.

But Video will be placed always in front of Stage3D. I need it behind it.