Show Us Your Iray Renders. Part II
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No its a sphere with the emission shader applied, the Lumen setting was dialed down to equal a 40 watt bulb,
so glad someone posted the watts to Lumen chart earlier that when into my notes on Iray render settings that I have been making.
I've been making a bunch of notes too. Still, check out the "Luminance Units" selector just under the Luminance slider under Emission. Two of the options are "lm" and "W". If those are what I think they are...
Luminance Units, if I understood the Nvidia Material Definition Language, correctly have to do with fall off over distance. what I need to take some time to do is hunt down some Emission Profiles, which are supposed define real world lights.
There are three parameters to make the image render longer, though only one of them will take effect at a time. Under render setting, progressive rendering; max samples, max time, and rendering converged ratio all affect how long it renders.
How long did it take to render? If it was two hours, then you need to increase the max time. If it was less than that, then it was probably the converged ratio that stopped it. I haven't seen an image reach the max number of samples before reaching something else first, but you can safely increase that too, I suppose.
The three settings jwood331 mentioned are what control the length of the render. If Iray reaches any one of the three, the render stops. The default settings are:
Max Samples: 5000
Max Time: 7200 (2 hours in seconds)
Rendering Converged Ratio: 95%
If you are rendering in CPU only mode, either because you don't have an Nvidia Cuda core video card or the image won't fit on the video card's memory, 2 hours is not going to be enough time for many complex images. Here are the settings I used to render the image below:
Max Samples: 15000
Max Time: 259200 (3 days in seconds)
Rendering Converged Ratio: 95%
The image took 3 days to render (CPU only) at 12382 iterations and was at 89-90% of image converged. (It sure would be nice to have that statistic in the Log file. Hint, hint.)
I used the maximum values for Max Samples and Max Time, but later realized these can be changed in the parameters just like any other settings. And, of course, you can remove the limits altogether. If you want an image to render to 95% regardless of the time or iterations, just change the limits and set these to something ridiculously high.
EDIT: It turns out you can, apparently, disable the Max Time limit by setting the value to -1. You'll have to modify the min value in the Parameter Settings to do this. (http://www.daz3d.com/forums/viewreply/798240/)
Nice image! I am excited to try Iray (i don't use DIM), but at 3 days for that scene, I would be curious how long it would take me in luxrender.
Yeah, it is beautiful. I'm wondering how much a GPU could help with the render time of that particular image. None of my renders have taken longer than ten minutes, though I haven't tried anything that complicated. I don't use my CPU to render at all, though.
that image almost looks like a photgraph!
however, i dont think im capable of leaving my pc alone fro 3 days since i use it for everyday things, plus, i dont think my clients are willing to wait 3 days per render.
While rendering, the System RAM usage was in the upper ranges of my 16GB. I'm not sure if that means it wouldn't have fit on 4G card, though. I'd love to get one, but I'm not sure my computer with it's 300 watt power supply could handle it. (I just bought this computer last summer, but I think I see a new computer in my near future, one that can handle a good video card.)
I've started using Iray optimized for Speed, too, but that image was rendered optimized for Memory. One of these days, I'll have to let it render it again just to see if the Speed setting makes any difference in the final render time.
I wasn't able to use DS for three days, but I didn't have any real trouble using other programs while the image rendered. There was some lag while the other programs waited for the CPU, but nothing that was overly frustrating. And I did do the render over a weekend. :)
Thank you all for the kinds words on the image. I wanted to do something that was just for fun, and then I got stubborn and wanted to see it fully rendered. I thought of stopping the render several times, but managed to wait in spite of my impatient nature. I'm glad I did.
Iray control the quality of the render, for example if you render just silver ball and set the samples to 15000 it will render only 60 samples and stop automatic as that is how much it take to render the material in the scene .
By increasing the render quality to 2 would double the samples to 120 but the rendering process slow down.
Scaling the Finite sphere when using HDRI maps will create much clear minder noisy images and produce better lighting .
Architectural sampler ON also improve the image and render time .
I noticed that Translucent materials and caustics take the most rendering time and create the most noises in the renders .
The three settings jwood331 mentioned are what control the length of the render. If Iray reaches any one of the three, the render stops. The default settings are:
Max Samples: 5000
Max Time: 7200 (2 hours in seconds)
Rendering Converged Ratio: 95%
If you are rendering in CPU only mode, either because you don't have an Nvidia Cuda core video card or the image won't fit on the video card's memory, 2 hours is not going to be enough time for many complex images. Here are the settings I used to render the image below:
Max Samples: 15000
Max Time: 259200 (3 days in seconds)
Rendering Converged Ratio: 95%
The image took 3 days to render (CPU only) at 12382 iterations and was at 89-90% of image converged. (It sure would be nice to have that statistic in the Log file. Hint, hint.)
I used the maximum values for Max Samples and Max Time, but later realized these can be changed in the parameters just like any other settings. And, of course, you can remove the limits altogether. If you want an image to render to 95% regardless of the time or iterations, just change the limits and set these to something ridiculously high.
Try changing the Optimization setting to Speed. It's set to memory by default. Go to Render Settings, Optimization, Instancing Optimization.
I've only tried on a couple of images that were hanging during the Iray render, but both are able to render fully with Instancing Optimization set to Speed. It might not help, but it's worth a shot.
Hi Male-M3dia,
Very nice render of M6. In my opinion, I think this one, and your previous render of 'Billy close up' have got the skin surfaces for each particular texture just right. They both look so photorealistic.
:-)
Interesting. DAZ_Spooky told us the Architectural Sampler was for interior scenes, and he also said it would increase the render time. Did you use it for interior and/or exterior scenes? I'm going to have to give it a try now. lol
I knew that about caustics, even before I created the chess set image. I haven't done much of anything with Translucency yet, other than a small amount for hair. But it makes a lot of sense that would add to the image's render time.
Thanks for the info. I'm adding it to my list of Iray tips. :)
well, just to make it simple, i dont want to have noise in my render, however, i cant also have the image take 3 days to render. my pc can handle it, but my (paying) clients cant. whats the optimal settings (ie, move X parameter to number Y) to render with the best quality in a rational time?
Yes that worked, thank you
As said elsewhere, Iray like light, lots of light. Dark scenes use less light and will take longer to render. I've had some scenes that were quite usable at 50% convergence or less when they were brightly lit.
Caustics add considerably to the length of a render. That was one of the reasons the chess set scene took so long. And there was only one light in the room. The rest of the light came in through the windows above the chess set. I used plane primitives to cover the open side and ceiling. Had I used several lights in the room, I'm sure the scene would have rendered faster.
Apparently Translucency also adds to the render time, from what Mec4D said earlier in the thread. If you don't need it, then you should stay away from Translucency.
Less complex scenes will take less time, as well. Every time you add a figure, prop or set to your scene, you are increasing the work the render engine has to do. More work, means more time rendering.
If you have an Nvidia, Cuda core video card and can keep the size of the image low enough to fit on the memory of that card, your renders will go quite a bit faster.
I don't believe there is a "one-size-fits-all" group of render settings to get the optimal compromise between speed and quality. Sorry.
Yes that worked, thank you
Great! I'm glad it worked. :)
As said elsewhere, Iray like light, lots of light. Dark scenes use less light and will take longer to render. I've had some scenes that were quite usable at 50% convergence or less when they were brightly lit.
Caustics add considerably to the length of a render. That was one of the reasons the chess set scene took so long. And there was only one light in the room. The rest of the light came in through the windows above the chess set. I used plane primitives to cover the open side and ceiling. Had I used several lights in the room, I'm sure the scene would have rendered faster.
Apparently Translucency also adds to the render time, from what Mec4D said earlier in the thread. If you don't need it, then you should stay away from Translucency.
Less complex scenes will take less time, as well. Every time you add a figure, prop or set to your scene, you are increasing the work the render engine has to do. More work, means more time rendering.
If you have an Nvidia, Cuda core video card and can keep the size of the image low enough to fit on the memory of that card, your renders will go quite a bit faster.
I don't believe there is a "one-size-fits-all" group of render settings to get the optimal compromise between speed and quality. Sorry.
,,,when you mentioned using several lights to make the scene render faster, would that be Photometrc lights or will multiple objects with the emissive shader do?
Architectural sampler should reduce the calculations and for that the rendering time.
Nvidia Iray website stated it improving both image and rendering time.
I rendered my last image using Architectural sampler and it finished one hour early than without.
I used translucency and SS plus glass mats.
I still testing out all the settings based on the info from Nvidia website and with better results
I knew that about caustics, even before I created the chess set image. I haven't done much of anything with Translucency yet, other than a small amount for hair. But it makes a lot of sense that would add to the image's render time.
Thanks for the info. I'm adding it to my list of Iray tips. :)
It is the only and right way as I do scale my HDRI maps this way , works fantastic
I'll give that one another go. I tried yesterday, but maybe it was impatience. :-)
,,,when you mentioned using several lights to make the scene render faster, would that be Photometrc lights or will multiple objects with the emissive shader do?
I've not done a lot using objects with the emissive shader, so I really don't know the answer to that. I do know adding two photometric lights behind a figure, with just a small amount hitting her shoulders, made an appreciable difference in the render time. I'll have to test it. It would be nice know.
...that would be great. Currently experimenting with indoor scenes but using only one photometric spot and several emissive lights.
well at least you gave me a few ideas. ill do what the other user said, and tweak the render time plus samples/etc. see what i can do in 3hour-rendering. ill go watch alexander or troy while its working. unfortunately i cannot post the result since this is an 18+ image paid for by a person.
...first indoor scene.
Used one photometric spot (shadow softness seems to do nothing for some reason), a plane primitive as with the emissive shader as a soft box (75W), also applied the emissive shader to the stained glass dome above the middle landing (35,000 lumens) and the glass of the background ceiling lights. Not sure why the ceiling lights are not illuminating the area in the background as I have them set at 25,000 lumens
Nice to see the old textures of the Grand Staircase set stand up pretty well.
Still need top work on the hair.
ISO 400
Aperture f11
Exposure: 1/125th
Render time 3h 19m 99% convergence
It's my understanding, because the photometric lights work for both 3Delight and Iray, there are settings for both render engines. The settings for 3Delight are ignored by Iray, and vice-versa. Shadow settings—Shadow Type, Shadow Color, Shadow Intensity, Shadow Softness and Shadow Bias—are for 3Delight. Shadows in Iray are what you'd get in real world situations. In theory, anyway.
Have you tried setting up several planes off camera and pointing your photometric lights at the planes, letting the light bounce back into the scene? I've got a photography lamp in my office, pointed at the ceiling in the corner behind my desk. While it's very bright above the lamp, the shadows on the other walls are very soft. (I've got to try this now! lol)
After doing indoor scenes only with the dome turned off, I decided it was time to move outside. Loaded an HDRI map. Added some girls on jet bikes. Found myself wishing for brightness and contrast controls for the sky dome. I suspect I'll be searching for a map with better dynamic range and figuring out how to use the sun. Clearly, more to be done. I also hope Monique doesn't clip that tree with her wing.
I also seem to have hung up. In previous Iray renders, after a brief time where only one or two threads at a time are in use, Iray seems to grab every processor and thread it can get its hand on until the render is complete. This time the render got to 97% and reverted to using only 1 or 2 threads of 8 available. I'm letting it run, but the pessimist in me suggested I do a screen grab and go with the 97%. (I haven't got an appropriate graphics card, so I'm doing CPU based rendering. I'm on a retina iMac with a 4GHz i7. I seem to be doing pretty well speed wise.)
Lighting a large space, Jack Tomalin's Hamam with Killian by Morris.
I'll give that one another go. I tried yesterday, but maybe it was impatience. :-)
Finally got a change to sit down, relax and try it. I think I went a little overboard with the settings on the first tries. So I got it working ... :-)
I'm still puzzled about what the other settings are used for. Like the dom x,y,z or the dome origing x,y,z
Thanks a lot
Just playig with the new iRay Engine. V6 with Optimized Textures for iRay, only Scene Light and iray Uber Shaders.
Adjusted White Balance in Lightroom. Only CPU rendering (old NVidia graphic card).
skin with Iray is HARD, I at least had a semi-ok handle on SSS with 3delight, now.. its all out the window.
It's a combination of skin and lighting that takes some learning, really.
Kyoto: if you want softer Iray lights you can change the photometric light geometry (it's one of the options), give it a size like, oh 100 height/width, and have it 'point at' your subject. The larger the geometry, softer the shadow.
However, the light object will show, so you want it off camera and it will show on reflective surfaces.
I think the softest lights will be emission surfaces. You can create a primitive and add the iray emission shader to it and set it outside the camera view (setting the opacity down may work too). Also change the luminance units to cd/cm^2.
I've noticed with HDRIs that come with jpg backplates that the jpg will look really washed out compared to the hdr/exr. Seems like a gamma correction problem....they usually match better if I set the Environment Map weight for the jpg to 1 and Gamma under Tone Mapping also to 1 (for hdr/exr I keep the defaults of 2 and 2.2). Since gamma also affects anything in the scene, I have to hide everything and render out the jpg alone as a new backdrop for the final render with everything unhidden and gamma back at 2.2.