iRay - strange Behaviour
AndyS
Posts: 1,438
Hi,
as I know it is possible to change certain parameters while the render is running. Especially the tonemapping values.
Most times I did this, the render continued with the current iteration (number). But sometimes it just starts really at the beginning with iteration #1. This is absolutely bothering (if the render took several hours up to that point).
Is there more behind it or is it a sponatious bug?
Post edited by AndyS on
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Comments
I haven't pinned it down myself yet but it happens to me. Could be down to convergence percentage.
Hm,
that's something I thought about too.
But I experienced it on several very different states. Even before the first percentage shown, at low percentages and even above 95%, which was really annoying.
My experience is that it's canvas.
With canvas off, it can pick up where it was.
With it on, it restarts.
Pardon,
what is canvas?
I looked into the advanced settings. There's nothing shown under "canvases".
So if it really should depend on this, I never changed some entry there, although the behaviour was different in some cases.
The restart can happen when not using canvases, too. It seems random.
The Canvas feature is under the Advanced tab: hardware, Canvases, Cloud (Beta). Click on Canvases.
Even so, it's not really beneficial to tweak tone mapping when rendering to a canvas, because canvases already support 32-bit output, which is over 20 stops of variation. When using canvases it's better to turn tone mapping off, give Iray a hit as to nominal luminance, then set tone mapping in the resultijg 32-bit image. You need a graphics program that fully supports 32-bit EXRs, of course.
Pardon Tobor,
didn't I say that I looked at that?
But is it possible that it depends on the kind of lighting?
I did an outdoor scene with sun-sky and was able to modify the tonemapping in a late state and iRay continued with the current iteration.
As I did a scene with only two spotlights and "Scene Only" it restarted at #1 after modifying the tonemapping setting.
That may be by incident. Don't know.
But it is not nice ("I'm not amused" as ER says). If it is possible to re-adjust some parameters during rendering, it should be consistent. Idependant of the scene setup.
Otherwise: --> BUG.
Yes, you said you looked under the Advanced tab, but the feature is indeed there, and that's what I pointed out. You have the same software I do, so keep looking! Enabling canvas is a matter of clicking the checkbox, then making other choices. There have been many threads here since the introduction of iray on using the canvas feature, so there's lots to search for and look at on how to use it.
I've not seen any rhyme or reason why the render restarts. Often, I can change settings and the render resume uninterrupted. Then other times not.
Yes,
but I don't understand your interference.
The point was that the restart had obviously somthing to do with activated canvas, as Will observed.
So I replied that there wasn't any entry in it on my side, although iRay restarted.
"Obviously"? No, it does not have something to do with rendering through a canvas, obviously or otherwise. It can happen with ANY type of render, and I made this point clear. I also mentioned that if you are rendering to a canvas, there is absolutely never a reason to adjust tone mapping in Iray. That's not how or where you adjust the exposure of the image. Since you don't tone map with a canvas, there's never a reason to adjust those settings during a render. Therefore, you'll never have it restarted that way.
You asked "what is canvas?" and I told you. You may call it "interference" but my comment was out of trying to help. I've learned my lesson.
I am also experiencing "restarting" of Iray. Sometimes it works fine. I will render a scene, and Iray runs to completion in, say, five minutes. Then, I will change the position of something, such as my camera, to get a tighter portrait. I run a new render, and Iray will "loop" and keep repeating "...iteration 1, 2, 3, 4..." then it restarts. Why?
Edited to add: I just restarted my system, then opened the exact same scene in DS, no changes, and rane the render. This time it continued to completion without the "looping" behavior. o clearly it is a bug.
Theoretically, changing the tomemapping setting during a render shouldn't start the render over; and yet sometimes it does. I have been unable to figure out just when that will happen.
Hi RLSprouse_ab199073ad,
of cause if you replace / change position one of the objects, iRay has to start from a new beginning.
But the change of "only" tonemapping or render quality parameters shouldn't.
At my current render, it continued correctly after changing tonemapping (F/Stop) and even the whitepoint. This time in an early status at still 0%.
So for the future be carefull with those possible changes. Especially at later status and long render duration.
I'm having the problem all of a sudden starting today. I have no idea why, but before today, I could play with tonemapping values as a render progressed without losing my iterations. Now, it restarts the render. And with the exact same saved file and saved settings. Weird. No, it isn't "canvases" in my case. I checked after reading this. It IS aggravating.