Trying IRay again ...
marble
Posts: 7,482
When 4.8 was released I was exited at the prospect of using IRay - I even have an NVidia card so I should have been all set. However, the facts of life were not so generous and I abandoned Iray for some basic reasons:
- My Nvidia card is not powerful enough (GTX 680MX 2GB)
- Attempting to use the GPU caused my iMac display to fill up with spurious artefacts (inside and outside of DAZ Studio - even on the dsktop)
- CPU rendering is painfully slow
I have a 2012 iMac with 24GB RAM and a 3.4 GHz i7 but that doesn't help the cpu render any faster.
I also have Reality/Luxrender but 4.0 was a step backwards in terms of speed and reliability so I shelved that while waiting for Reality 4.1 and Luxrender 1.5. They are here now but I've just spent a week reporting issues on the RDNA forum and have decided that the experience is too frustrating. 3Delight is always reliable but I can't get the quality I could get when Reality works.
So my options are diminishing. I have decided to try again with IRay and also with Blender Cycles (though I'd appreciate any comments on the mcjTeleBlender script before I dive into yet another Blender black hole).
I can see by the forum threads that very few Mac users go with Iray and that most are PC users with powerful GPU cards. Is there a thread that I have missed which explains how to optimise the settings for CPU renders (i.e speed). Also, the one thing that sets Luxrender apart is that it can operate apart from DAZ Studio. I believe that IRay works within DS so that I can't work on another scene while the render is taking place. Another thing that Luxrender has is the ability to adjust Tone Mapping and Lighting during the render. I found that IRay has a slide-out panel which allows for changing Tone Mapping settings but I also found that the render resets and starts over when any setting is adjusted, which seems ludicrous to me. Am I missing a trick here?
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Attempting to use the GPU caused my iMac display to fill up with spurious artefacts (inside and outside of DAZ Studio - even on the dsktop)
Which nVidia drivers are you using? Are you using the one shipping from Apple ot the nVidia driver called "WebDriver" that you download from nVidias web?
I'm a PC user and I do not have an Nvidia card so all my renders are cpu only. Perhaps for that reason, I notice when a fellow DS user mentions he/she is rendering cpu only. There are a lot of us, but I think we are mainly the hobbyists in the community.
It's true that Iray works within DS but it is possible to have two instances of DS open at the same time. The render will try to use all of your computing power. If your 3.4 GHz i7 is multi-core, you may be able to limit the number of cores used by the copy of DS doing the render, and then work in the other. (I can do it on the PC, so I'm assuming it can be done on the Mac, and probably easier.)
From what I've read, I believe the issue with the render restarting when you make changes in the Tone Mapper is due to Iray code and until Nvidia changes the code, there is nothing DAZ can do for us.
The default render settings are optimized for speed, but one thing that really slows things down is rendering objects with 3Delight materials. The program has to convert those over to Iray before it can start rendering and adds overhead to each render. Manually converting those to Iray beforehand will decrease the render time.
As for the Nvidia card, I've read most who already had Nvidia cards have had to update the driver. And some who have updated the driver have had issues and had to go back to the driver they started with. It's still worth looking into.
I don't know how much of what I've said you already knew, I just hope I've been able to help some. And hopefully others can share some of the things they've stumbled on that help speed things up, too. I know I'd love to learn a new trick or two to increase how fast images render, (besides staying away from dark scenes, which I'm partial to.)
I'm a bit stumped in remembering how to find the driver version number but I do remember downloading them from NVidia some time back. Maybe I should just get the latest again?
As for speed, I get confused because I've seen it started that Iray in CPU mode is faster than Luxrender but I found the opposite - even before the latest "super-fast" version of Lux/Reality 4.1 (which is not super-fast in my experience but I can't speak for others). I did attempt to follow the SY beginners tutorial and so I did mass-select/convert to IRay shaders. I guess I'm not really understanding the lighting. The Lumen values, for example ... the tutorial says something like "add lots of zeroes" which doesn't fill me with confidence, especiall as the lighting is so crucial and a delicate balance between Tone Mapping settings and individual light settings.
This is what I can find for NVidia on my iMac (see attachment).
I looked on the NVidia web site and there are no drivers for OS X listed so perhaps I didn't get them from their site after all.
Edit: I've just updated them (see second attacment) ...
Well, the point about lights and "lots of zeros" is that the Tonemapping settings are imitating a camera that takes a picture on a bright, sunny day. When you use these settings in a room, and use just a 60-Watts spotlight, the room is just way too dark.
The easiest way to solve it is cranking up the lumiance of the lights - from 1500 to 45000, for example. The other way is to adjust the tonemapping, using a value of 4 or even lower instead of the 8 that is default.
Here's something I set up a while ago in another thread:
Here are some screenshots for Illustration. I apologize for the bad quality. I stopped the renders at a very low number of iterations.
The scene in this test render is always the same. The only thing that changes are the lumiance/temperature of the lights, and the tonemapping settings.
The "camera" default values (the tonemapping settings) are perfect for a sunny day outdoors. My test scene is indoors and very dark.
First, this "firelight" at default setting.
This is Firelight at changed tonemapping settings.
Second, this replaces the firelight with a setting that emulates a 100 Watts light bulb.
Default tonemapping:
Changed tonemapping.
Third, this setting emulates a 400 Watt Metal Halide lamp.
Default tonemapping:
Changed tonemapping.
http://www.daz3d.com/forums/discussion/comment/869852/#Comment_869852
OK thanks. That makes sense - I can either bump up the light power or adjust the camera/film settings (e.g. ISO 400). Is there a preference? I seem to remember when I first got an SLR camera (30 years ago) I tried ISO 400 film and the results were usually grainy.
I'd crank up the light. Here's something I did a while ago (original thread http://www.daz3d.com/forums/viewreply/820983/ )
Here are two examples of Point light. Please look at the render settings at the right side of the screen.
The first image is Default, at 1500 lms, no other light source.
The second has the point light cranked up to 500.000 lms.
The next pait is a linear point light. They are basically the same as a point light, but you can adjust certain features in them.
Again, one render at default, one at 500.000lms
What you always have to keep in mind is that in Iray, light behaves like normal light, so it will decay with distance. If you want to lit something far away, you need a stronger light.
Here's the spotlight pairing, same numbers, default and 500000
And here's distant light, which is the only light which doesn't decay over distance. So, the object gets hit by the full strengths of the light at 1.500lms.
If you dial down the strength to 15 lms, it looks okay.
And last, but not least, the HDRI default, and the sun-sky setting.
HDRI
In the sun-sky setting, you can tell the system at what position the sun is standing by using the coordinate and time system (marked in the image).
You can also prop the sun to a light, but that doesn't always get the right results, so I prefer the coordinate-time system, personally.
Combining a point light and a dome scene:
Some helpful stuff there, thanks. I'll take my time and digest it all.
By the way, wasn't there a change in the Lumen setting since the initial release? So now it is not an additional 10 zeroes but maybe 2 or 3?
You can use the Sun Dial to position the Sun.
Under the Content Library tab you will find it by navigating to Render Presets>IRay
In the Render section you will find it under Render Settings>Presets>Iray
It's called the Sun Dial Set.
Or use a camera:
http://www.daz3d.com/forums/discussion/comment/879523/#Comment_879523
Most of my renders are interiors so I guess I would not use the sun or HDRI or Dome. Maybe for light coming in through windows though.
This was the first method I was pointed to. I was using this method and I couldn't get it working in a scene. The shadows were not falling where they should have. For some reason it was not working for me and I was then told about the Sun Dial Set. Turns out the Sun Dial Set worked for that scene. This is the method I recommend.
marble, check out this thread: http://www.daz3d.com/forums/discussion/comment/869852/#Comment_869852. I created some indoor-lighting suggestions there (scroll up from the linked post).
My only recommendation is to keep experimenting. There's a lot of frustration involved, but if you start with smaller, simple scenes, you can do a lot of rendering without it taking too much time, until you get a feeling for what works, and what not.
Oh, and changing the ISO to 400 doesn't give extra grains or other problems. The tonemapping is similar to real photo, but not the same thing.
I read in an earlier thread that the render restarting after you change the tone mapping is a bug and that the beta version didn't do this. But it is a bug in Iray, not Daz Studio, so NVidia will have to fix it.
Some really helpful comments here - thank you all :)
I did a test with a Camera as a Sun Node. I turned off the headlamp on the Camera. I did these tests. Sun from above, from the front, and from the left. If this method gives you problems try the Sun Dial Set.
According to Chemicq http://chemicq.deviantart.com/ it even reacts to lowering the camera to create a different time of day
The restarting thing all the time is annoying, but one can set everything with iray draw 1st (but limited to having an nividia card) which I find practical. I am having the opposite problem. I would like some renders to bake a bit longer sometimes but it seems no matter what I do iray will stop at some point the renders do look completed and I do have decent systems and good cards. Prior to changing the AMD to GTX980 in my tower render times were much slower. As for Reality I have packed it in after 3 years. I have newer systems including a 3 month old 24G laptop. Lux runs slow. Over 6 hours with GPU boost. Enough was enough..
LuxRender does take a long time. This render took about six hours (this is an old scene I redid with Reality 4.1). I enjoy using LuxRender, it also insures that I don't loose a render that is five hours in when the lights go out. I just wish it was faster. The results are still great.
No doubt. still some render noise on the skin. Had the same with 6 hour GPU boost.. I am sure I may need it the odd time but 6 hours is no longer the "norm" for me. Still its not the 20X using CPU that was claimed. Between that and "It will be out in a few weeks" back in late April, I think Paolo has his own set of mathematics LOL...
OK - so now I'm remembering why I gave up on Iray. I have a render going right now and it was started 20 minutes ago. Iterations are at 300 and percentage is at 0.09% ... not even 0.1% after 20 minutes! Unless the progress is not linear, I'll be waiting a week for this thing to reach 90%.
EDIT: Perhaps it is not linear because another check at 27 minutes and it is up to 0.4%.
300 iterations and only at 0.09%? That doesn't sound right.
What's your scene setup?
(Also, you don't always need 90%, just like in Luxrender, you can stop at any time when it looks good.)
Scene is 3 people, clothes, a room and furniture. I have a plane primitive as a single-sided light (taken the hint from your thread) and two spotlights. It is a little too well lit for my tastes but that's something I can play with (if only that during-render tone mapping worked). I understand that I can stop it when I'm happy but I assumed that might be somwhere around the 80 - 90% mark.
Here's some screen shots ...
First and foremost...is everything in the scene converted to Iray materials? The autoconversion, may be fine for something, but it isn't the most efficient when it comes to render times.
Yep - I did select everything and converted them manually.
Marble, try a very simple render to start with using one nude figure and lit only by the default hdr that comes with iRay, and then tell us how long this takes to render. With my GTX 970 this takes around 50 seconds for me to render, and using CPU only it takes around 2.5 mins (although it looks fine after a minute and a half). I was using V7, but you can try any figure, preferably one with iRay shaders. My PC is probably faster than your MAC, but if a simple one figure render is taking you longer than 5-10 mins, something seems wrong. After this, build up to more complex scenes, and you will discover what it is that is making your renders so long.
Well, I'm using this particular scene as a comparison with Reality 4.1. That took about 2 hours for a decent render of this scene. Right now, the Iray render is at 1hr 30m and is now showing 32% convergence. Actually, I've just realised that it isn't a direct cmparison because this render is 1200 x 900 whereas the Luxrender one was 1600 x 1280.
As I mentioned before, iRay can take longer for me, in CPU mode, than LuxRender 1.5. Darker scenes especially and scenes enclosed inside a room prop (there is more light bounce in such a scene). They can take a lot longer and in many cases the noise just will not clear. You can play with the tone settings all you like, but if you want your scene lit at a certain level, you have to live with it.
Yes, well, rendering a test pinup is one thing and I was happy with the performance of Lux on those kind of scenes. But I'm more interested in how the various engines perform with the kind of scene I usually produce - almost always indoors, usually multiple figures and props and often with glass or reflective surfaces.
So far I've rendered this scene in Reality 4.1 CPU (with and without boost), Iray CPU mode, 3Delight and Blender Cycles. IRay so far is coming last. Cycles was quick but I am a complete novice so the materials didn't convert very well but those that did looked good. 3Delight is also quick but it just lacks that element of realism that a PBR can produce.