I’m not exactly sure how to describe it but I’ll try. I have a scene that’s quite heavy. Everything by default is enabled and preloaded. The PlayCanvas canvas is hidden but running in the background. When I show, I also move the camera to a part of the scene that is heavy on geometry. And it takes 5 solid seconds to actually display the canvas.
In another part of the scene, I hide the nacelle of an engine to show the engine itself and I show/enable internal components. And again it takes a few seconds to kick. Any idea why?
Check your profiler and specifically the shader compilation time. I’m pretty sure what’s happening is the moment you move your camera to that part of your scene, the rendered for the first time materials compile their shaders.
That’s a common issue with shader compilation, there are a number of topics around on how to work around it. A common approach is outlined here: