Hope everyone is doing great.Been pondering on this for a while,out of curiosity more than anything.Been using Maya with Arnold for a while now.Just for hobby stuff,mostly simple renders to compare with my path tracer.I realized their Renderer has this really nice feature that lets you see the image as it renders.... Progressively.It seems to start from a lower sampling and aa amount and then re-renders the image as it increases those parameters automatically.I thought it was really cool.And a nice way to show preview of renders before they reached their maximum quality.It made me very interested to do the same for my path tracer I am Working on.Currently it waits for the whole render to complete after which it saves a simple ppm file on ur drive. My question now is.....Does anyone know how something like this can be done? I have tried my best to find out and the only information I came up with was that OpenGL is involved somehow.I'm not looking to create the same thing as Maya.Just a simple window that pops up as the render starts and progressively makes the image better. Again.....this is more curiosity than anything else.As much as I think it's really cool Thanks :)
It is not restricted to OpenGL in any way. You design your renderer to run in a separate thread (possibly multiple threads or even multiple machines) and progressively send the partial results to the main thread. The main thread then creates a window that displays those results as they come in. No magic here.