XM Magdalena 3D print, GGeorgy (3D)
LC #42 Pipers Alley

View Full Version : Final Gather Map question

11-14-2006, 05:57 PM
I am rendering a fly-through of basically a box. I have the final gather map read/write file enabled so the final gather points are being written to and read from a file on the network. I am getting very bad flicker. When I enable Read Only (FG Freeze) and points are no longer being written to the file, just read, there is no flicker what-so-ever. I have a couple nodes over the network using this file to render from.

It seems to me that, when one machine is rendering, for example frame 100 and writing the final gather points, another machine starts rendering 101. Since the the final gather compute for frame 100 is not finished yet, frame 101 starts writing different points. The result seems to be a very bad flicker, where frame 100 and 101 have very different FG point layouts.

Does anyone know how FG map is supposed to work when different machines are rendering, for example frames 100, 101, 102 and 103 at the same time?


*edit* found Jeff had answered this over here:


"So is this as simple as choosing a new file in the FGM file slot, then setting the render to every-nth-frame, running it (does it have a way to just calculate FGM and not do final rendering like in Vray, or do I just have to minimize the time loss by setting the image sampler to 1/64?) then when it finishes, freeze FGM and do the render? And I'm assuming that it will behave like Vray in that if there are parts the camera didn't see in the every-nth-frame those will have lighting errors?"

11-18-2006, 01:06 AM
I am using this technique and its working like a charm, no flickering at all. However, computers that are using the 'frozen' FG file still take a very long time 'computing final gather points'. If 'read from the frozen file' is all I have selected, and there is no flicker so I know the points are being pulled from that file, why is it that on every frame all my computers 'compute final gather points'? I have not timed it, but I would guess the FG computation takes the same amount of time if no file was being used, how can this be?


CGTalk Moderation
11-18-2006, 01:06 AM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.