From: Tim M. <tim...@gm...> - 2013-04-26 08:56:52
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On Fri, Apr 26, 2013 at 8:39 AM, Renk Thorsten <tho...@jy...>wrote: > > I've also taken a bit of a look at merging Rembrandt and ALS, and I think > > I understand the Rembrandt pipeline enough that I could add ALS to it. > > Just to provide some expectation management: > > Rembrandt (as deferred rendering) is very heavy on the fragment shader. > ALS at low quality is currently rather balanced between vertex and fragment > shader and at high quality adds all additional load to the fragment shader. > An ALS implementation in Rembrandt will require that basically all light > computations which are currently in the vertex pipeline move to the > fragment shader as well. That's not a small workload, sunlight is about 100 > times heavier to compute in ALS than in default or Rembrandt (that's what > ALS burns framerate for). > > I don't think it's quite that bad. In a deferred shader like Rembrandt, the ALS would run in the deferred lighting pass. While it's true that the heavy work is done in a fragment shader, it only runs for each pixel on the screen, not for every rendered fragment. Also, in many cases the sky would take up a large portion of the out-the-window scene; is computing ALS for the blue sky as expensive as for an object in the scene? Not to mention that you don't need to run ALS in the cockpit... Tim |