Feature Request: Set random seed for deterministic rendering

[nimrod-gileadi]

Is your feature request related to a problem? Please describe.

I'm using Filament for off-screen batch rendering. It would be useful for me to have deterministic results, where rendering the same view twice results in the same pixel.
For the scene I'm using, I'm able to achieve this by disabling dithering, but it would be nice to have dithering, and just be able to set the seed before I call Renderer::render.

Describe the solution you'd like
This could be achieved by making FEngine::getRandomEngine a public method of Engine (so I could call engine->getRandomEngine().seed(1234)), or you could have a narrower interface with one function for setting the seed between render calls.

Describe alternatives you've considered

Disabling dithering (my current solution), or casting Engine* to FEngine* to get access to getRandomEngine().

[romainguy]

Dithering doesn't use a random seed but it's based on elapsed time.

[nimrod-gileadi]

Thanks for the correction. Is there a way for a client to explicitly set the time used for dithering?