Talk:Hackathon Proposal: CompositeViewer and Canvas

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Performance

FWIW, I don't seem to recall seeing any performance issues back when we were prototyping the original CanvasView element. However, that was obviously not using CompositeViewer (single window/GC). In general slave cameras are cheaper, and at least for static cameras or those fixed to an aircraft (exterior views like tail/gear/FLIR etc), they might still be preferable?

In fact, CompositeViewer is usually needed whenever we have an *independent* entity (where object A may see a completely different part of the scene than object B, so that B may no longer get access to the PagedLOD nodes that A discarded already), but if the camera can be "slaved" to a parent object in the scene, that's probably what should be done? Looking at osgcompositor.cpp, it can combine both kinds of cameras at runtime.--Hooray (talk) 09:53, 16 November 2020 (EST)

Not sure whether this relevant, but Fernando said that Canvas uses scene-graph cameras, and it seemed that the use of scene-graph cameras caused some issues with canvas-view, but it would be quite a lot of work to change canvas to use slave cameras?