pre Yeah, the way Godot handles offscreen buffer rendering (using viewports) is kind of stringent. The devs should think about implementing a more flexible system.

You'd have to go with multitude of cameras/viewports but I think Godot may handle it well if you run it on powerful enough hardware. And you can always render is several passes, each handling a certain amount of cameras.

Right, there we go, that seems to have it.

You just gotta accept it's going to take several frames to pan the cameras around so you're gonna have to freeze your game.

Made it so you can adjust the number of camera-pairs it uses for each eye from 4 upwards. I found 64 or 128 is about the best number of cameras before it starts getting to memory intensive. Render time then is only like 30 frames, but most of them are long ones.

https://github.com/revpriest/godotPanoRenderer

One interesting thing is that if you set the canvas-size of the subviewports for each camera to just 1 pixel wide they get no lighting showing. I was fiddling about trying to figure why the lights were all on a different layer or something but turned out just the camera was too narrow to let light in or something. Needs at least a five-pixel wide render in order to have any lighting at all really.

Thanks for your help folks.