iRay Resume Tip
acanthis
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Post edited by acanthis on
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awesome tip. thanks!
Very good tip indeed!
I knew about this, but what I don't know- when it is rendering, before it starts saving, it says Render Target Canvas was Written. Question is- is that based on the amount of samples and time you have selected? Or will the time for writing the canvas be the same, regardless of the amount of time/samples I have? The image starts coming in before it starts with the percentage of the render, so I am curious as to how the samples/time that you put influences the writing the canvas and rendering percentages.
As Iray rendesr, it sends back signals to its host app (in this case D|S). The default interval for these updates is five seconds; they are not instantaneous. You really don't need to change the update interval, but feel free to experiment to see if some higher setting improves speed, especially if you have your CPU contributing to the render.
More than likely, the "canvas" has been written to and updated before it says it has. It's simply in the timing of the update messages.
That is an excellent tip Acanthis, thank you!
You can, actually. But not while it's rendering. Hit "Cancel" to pause the render. In the main window menu, click on File and scroll down. You'll find "Save Last Render" listed. After you've saved the image, go back to your render window and hit "Resume." (I read about this in these forums and use it a lot. I'm happy to pass on the info.)
Are you talking about the same thing that I asked about? I didn't mention the interval, I asked about the max samples and max time. If you have either of those too low, the render will stop. So my question was, if I increase the samples and the time, do either of those impact the "Rendering Image" with the percent showing while it says render target canvas was written. (And thanks for trying to explain, perhaps I am not getting how your answer about the interval answers my question on max sample/ max time.)
So what would happen if as well as increasing the render time, you also increased a setting for a light, and then resumed the render? Would DS then resume taking into account the new light setting? Or is that too stupid?
Ashley: No, but I wish it did. Would be very nice to be able to adjust bump and other minor settings, as well as lights, and have it recalculate.
I guess I'm not understanding the question. The progress will differ for every scene and setup, even with the same Progressive Rendering settings. I've had some renders that took 5 minutes before the first "canvas written" update was received; in others it occurs seconds after starting the render. Max samples and time (and convergence ratio) are only "stop-at" signals, so you can start a render and walk away, knowing the render will eventually stop at some predetermined point.
The percntage bar is a crude, and often inaccurate, estimate of render progress. It's based on convergence ratio. A render can stop before 100% progress if time/max samples is exceeded. Though the Iray programmer's documentation don't spell it out, I imagine the "canvas written" updates are based on things like available memory, so that too will vary between renders.
What I though you were asking is if the frequency of update message affects rendering, and the answer to that is yes. If you don't need to see all those messages quite so often, you can improve performance by setting a higher update interval.
"...increased a setting for a light..." Are you talking about changes to Tone Mapping? Or are you talking about making changes to your scene lighting?
If you make changes in Tone Mapping, such as increase or decrease Exposure Value, the render will start over. The next reported iteration following a change will be "1." You can make changes to Tone Mapping, Filtering and Progressive Rendering while the image is rendering via the left menu of the rendering window. If the render is paused, they can also be made from the main DS Render Settings tab and will be applied when the render resumes. Only changes to Tone Mapping will cause your render to restart. Changes to Filtering and Progressive Rendering continue from the point where you made the change.
All the information to render your scene is in memory (RAM.) Other than the supported interactive changes to Tone Mapping, Filtering and Progressive Rendering, you can't change the information in memory for that render window. So if you pause the render and increase luminance on one or more of the lights in your scene, those changes will not be reflected in the open render window. You will need to start a new render to see those changes, or any changes other than the supported Rendering Settings.
These are good questions. Those of us who've been playing with Iray since the Beta came out in March had to learn a lot of this stuff through trial and error. And some of it, like the interactive settings and the ability to resume a render, came out of beta testers reactions and (strong) suggestions to the development team.
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Removed
Does not work for me. L'Adair had made the suggestion when I was (and still) unable to set an endless render no matter what settings. When I try to extend quality or time, the resume becomes available. Once I hit resume it just goes blank again and nothing happens and so on... I tried going back to the luxrender cause it will let me render as long as I want but in spite of owning 2 newer decent systems I still need 4 to 8 hours for a render...
First, I want to be clear here, DS/Iray does not have an endless render. With Max Time set to 0, Iray will render until either Max Samples or Rendering Converged Ratio is met. Increasing the Quality setting will increase the number of samples needed to reach the Rendering Converged Ratio. But at some point, Iray will stop on it's own.
I'm wondering why you seem to be obsessed with resuming your renders. Am I misunderstanding what you mean by the render stopping at 70 minutes? Is the render incomplete in spite of your settings?
Also, I have never heard of the render window going blank when resuming a render, until now. Even when I make changes to the Tone Mapper settings and the render restarts, the window remains the same until the first update.
I'm beginning to wonder if there is an issue with your video card...
I think you should let Tech Support know. Maybe they've seen it before and have a solution. If nothing else, I think they'd pass the info on to the Nvidia Iray development team.
Obsessed LOL I read somewhere that you never got the hang of Reality & Luxrendering where one can run the render until one is satisfied. That is the concept of unbiased rendering if I am not mistaken. I have had iray renders "end" with some slight noise that I post worked out. I did not mean the render window itself goes blank but the resume button thingy. Render ends> extend quality & time or both>resume button enables>hit resume>nothing happens>resume button just becomes blank or unavailable again. Makes sense? I have 2 systems so it's not a card/ system problem.. I know about the renders re starting hence why I tweak stuff with iray draw..
Im using both rendering engines fun fun...
Double post grrrr
Oh, glad to hear it's only the button graying out. I was trying to duplicate the window going blank, so I set the max samples really low with quality at 1 and Rendering Converged Ratio at 95%. When it stopped, I set Quality to 2 and converged ratio to 100%. But I didn't increase the Max Samples. Iray started to render, and then quit immediately as it was at the Max Samples already. And it grayed out the Resume button... Sounds kind of like what you are describing. But I'm confident you increased the Max Samples when you upped the Quality. So, it's just weird.
I'm pretty picky about the finished render quality, too. I've been known to let my poor computer render on for days to reach 95-100%. The cost of running cpu only...
The problem I had with Reality/Luxrender was with lighting. When I first started playing with it, not knowing what I was doing with DS either, my first luxrender renders were simple with the perpective view and the headlamp for lighting. Nothing great, but I don't think I noticed any increase in quality after a day or so. I finally gave up. I bought Luxus last January. Before I could make the time to figure it out, the beta was releases with Iray... I never looked back.
Cool I used Reality / lux for the past 3 years. Produced around a few thousand renders (long winded stories & commissions) Reality 4 takes a lot longer then 2 did. 4.1 is faster but some bugs need to be ironed out. Once they are they will be close in times. My average iray times are between 60 to 90 minutes. I was using iray but also went back to lux this past weekend. I can produce stuff that take a bit longer with lux and render others in iray balances out that way. Iray run my machines alot hotter then lux..
It finally works! I set a new fresh scene today set the long settings and finally at 54 minutes and still 0% (the render is progressing) but now I can decide when its good enough!
Yeah. It's like constantly redlining the tachometer on your car!
Yay! I'm glad you finally figured out what was stopping your renders.