How to get better and faster renders with Iray?

novelist999

L'Adair said:

One way to soften shadows is to set the spotlight Light Geometry to disc and increase the size of Height (Diameter) and Width.

Increasing the size of the light may also work with other Light Geometry settings, I haven't tested them, but it didn't make any difference with the default Point setting.

Thank you. I'll try that.

novelist999

hphoenix said:

Suggestions for a new Graphics card should have your budget for one included.

Best performance?  nVidia Titan-X.  Cost $1000 + new power supply for computer.

Best bang for the buck?  nVidia 970GTX.  Cost $330 (maybe + new power supply)

Cheapest with decent performance?  nVidia 740GT 4GB.  Cost $100.

Without knowing more about the actual budget, we can't make much better recommendations.......

 

Thank you. That's very helpful! I'll check into those. I'll probably go with the Nvidia 970 GTX if my motherboard can handle it. 

novelist999

jdavison67 said:

FOR IRAY

Keep in mind if you have a scene larger than the amount of memory than your card holds, it will not be used, and will only serve as a heater in your chassis, so get as much memory that you need, and maybe a tad more, for the typical size scenes you render.

The higher the cuda core count = more speed as long as your card can fit your scene in it's memory.

If you have two 2gb cards they do not combine to equal 4gb.

if your scene is 3 gb, niether card will be used at all, the scene to be rendered has to fit in both cards individually, or you will be doing a CPU render only.

I learned this the hard way.

JD

I'll keep that in mind. Thanks.

novelist999

j cade said:

I have a 2GB video card, and you'd be surprised what you can fit on it (I'm on a laptop so there's no switching out for a better card for me in any case).

 

For softer shadows with Iray point (or spot) lights the key is in the parameters panel setting the "light geometry" to something other than point  (I like rectangle personally) and setting the height and width a bit bigger.

 

 

Interesting. I'll have to try the rectangle. I had no idea I could change that. Thanks for the suggestion.

novelist999

Tobor said:

Simple things to decrease render times:

* Be sure there's plenty of light in the scene. If you have to alter the tone mapping settings from their defaults in order to get a brighter image, you should instead look into increasing light levels.

* Make sure *every* surface in your scene uses Iray materials. 

* Check that black background. If it's a photo backdrop, remove the backdrop and just render to a transparent background. Use Photoshop or other graphics program to add in the backdrop.

* Avoid unnecessary alterations to render settings, like using anything more than the default 95% convergence ratio. Get your quality by using better lighting.

On the shadows, as noted you can change the light geometry to a much bigger surface, which (like in the real world) will diffuse the lights. However, it will mean a *slightly* longer render time.

Your son is somewhat right about the graphics cards, but that warning is really more for nVidia cards that are distinctly different, like GeForce and Quadro. You can usually mix-and-match if both cards are GeForce (many of us here do), and especially if they use the same driver. Your 630 is available in some different versions, with different number of Cuda cores. You might be able to keep it, and use it as the primary monitor card, along with a lower-end 9xx series card. A primary concern is your power supply. Some cannot provide enough amps to run two cards, even smaller ones, plus there's the matter of insufficient power connectors, PCIe slots, and so on. All of this must be considered.

Depending on the size of textures and a few other things, a single character with clothing and hair might fit onto a 2GB card that is also driving your monitor. Download and install a program like GPU-Z to monitor your card during rendering.

Wow! A lot of very useful information. Thanks for sharing. I'm anxious to try your render suggestions. I had no idea that I could render to a transparent background. I'm used to rendering on a colored background with alpha channels in Poser, which I always remove during postwork. 

novelist999

mtl1 said:

novelist999 said:

I'm an experienced Poser user and new to Daz Studio. After many experiments, this is my render of The Girl 7, using Iray and three point lights. The shadows are way too heavy especially in the folds and crevices. Is there a way to turn the shadows down?

I guess I'm suffering a lot of confusion about the lights and render settings in Daz.

This render took an hour, which is way too long for me. But I've decided that I want to learn Daz Studio, because I love this character so much. So I study tutorials each day.

I realize that I need a better graphics card as I have a 2 GB Nvidia GT 630, which isn't powerful enough.  Any suggestions about a graphics card? I can't afford an ultra expensive one. My son told me that I'd have to either replace the one I have or get another just like it as they can't be mixed and matched.

An easy way to speed up computation time is to use Interactive instead of Photoreal under render settings. Interactive is a biased render, but it produces similar renders compared to Photoreal.

There are other Photoreal optimizations you can do too, such as changing the path length or even your light source.

Good luck :)

I had no idea. I've been using Photoreal. I'll try that. Thanks. 

novelist999

DustRider said:

novelist999 said:

I'm an experienced Poser user and new to Daz Studio. After many experiments, this is my render of The Girl 7, using Iray and three point lights. The shadows are way too heavy especially in the folds and crevices. Is there a way to turn the shadows down?

I guess I'm suffering a lot of confusion about the lights and render settings in Daz.

This render took an hour, which is way too long for me. But I've decided that I want to learn Daz Studio, because I love this character so much. So I study tutorials each day.

I realize that I need a better graphics card as I have a 2 GB Nvidia GT 630, which isn't powerful enough.  Any suggestions about a graphics card? I can't afford an ultra expensive one. My son told me that I'd have to either replace the one I have or get another just like it as they can't be mixed and matched.

Great render! I'm a big fan of The Girl too.

Without some serious hardware, you probably wont get render speeds with Iray as fast as you were getting with Poser. Poser is a biased render engine, which basically means it uses sampling algorithms to quickly calculate the effects of lights on objects/materials, where Iray uses physically based lighting and materials (and brute force) to calculate "actual" light effects for everything in the image. So unbiased render engines like Iray are much more processor intensive (slower) than biased render engines (thus, why GPU processing is a huge plus). The trade off is that materials/shaders and lighting is much more consistant with unbiased or PBR renderers, so scene set-up and modifications are typically much faster. That being said, you can definitely improve your render speeds with an upgrade. There are three different versions of the GT 630, so it is hard to be sure exactly what card you have (two with 96 Fermi cuda cores, and one with 384 Kepler cores - due to the changes between Fermi and Kepler it takes approximately 3x Kepler cores to equal the performance of 1 Fermi), but it seems that the specs for performance are similar, 

If $200 is in your budget, I would recommend a GTX 960 with 4Gb of RAM. You will get very good render speeds, and it comes in two sizes (full size or compact size for smaller boxes) and only needs a 400W power supply, which is the same as what Nvidia recommends for the GT740 (the GT 630 needed a 300W power supply, so you may need to upgrade you power supply for either card). The GTX 960 has 1024 cuda cores and should give you a render speed increase of approximately 7x or better (see here), the GT 740 (384 cuda cores) will give you approximately a 2X boost in performance (see here). I just built a system with a GTX960, I picked the GTX 960 because of the combination of it's price, performance, and lower power consuption (bare bones system with a 500W power supply).

Unfortunately, I can't give you any sample renders/times using the GTX 960, because it's busy doing processing on a huge 3D photogrammetric project I'm doing (I built it for this project, and it will be running non-stop for the next 2 weeks). I have a GTX 970M in my laptop, which has about 4/5 the performance of the GTX 960, and am very happy with it 

This render took about 8 min. on my laptop (1429x2000pixels), lit only with an HDRI.

This image took about 45 min. (1600x2000 pixels), lit with an HRDI and 3 mesh lights.

Wow! Fabulous renders! Thanks for the information! A speed increase of 7x or better sounds like a dream come true. I'll definitely check into that video card. I'm not sure which kind of cores my card has. The card came with my HP computer, which I bought about a year ago. It has never seemed to have much power. It's defintely time for an upgrade.

novelist999

outrider42 said:

You can also try turning off the normal maps in the surfaces tab on you character if they have any. I doubt you will see any difference in the render results, and it should knock off a few minutes of render time. There is also that down sampling trick some people use: http://buerobewegt.com/quicktip-rendering-even-faster-in-iray/

I decided to run a little down sample test since I have Girl 7. I used Tinkerbell Hair, which probably cut a little time as it is a simpler hair style. I just used all default iray settings for the basis of this test, adding mesh lights would add time. At 1300 x 2500, my GTX 670 2gb was able to render my test pic in exactly 6 minutes flat. (You can view the full image by opening the image in a new tab.)

After that test, I tried down sampling. I rendered the exact same scene at 2000 x 4000, and stopped it at 56%, which was at the 3 minute mark. Then I went to Gimp and resized my picture to 1250 x 2500 (yeah, not exact.) The results were pretty much the same.

So give down sampling a shot.. Just remember you still need to stay within your graphics card's vram. Go too big and the gpu will drop out, leaving the cpu to chug very, very slowly by itself.

I also recommend the GTX 960 4gb. This assumes you budget is around $200. If that is more than you want to spend, I still recommend considering it. If Daz is something you are really interested in doing, you will thank yourself later. There just is no substitute for raw power when it comes to iray. Just remember to make sure whatever you get will fit your case and that your power supply can handle it. The GTX 670 I have is in the ball park with the 960 in power. I'm not sure how they compare in Daz, but as a gaming card, the 670 and 960 are actually close in some areas, with one card doing better than the other at certain games, but the 960 is generally better overall. So I'd wager a 960 would perform at least a little better for Daz, especially the 4 gb version. G3 characters take up a ton of vram, and having 2 gb is quite frustrating. As for me, personally, I am trying to hold out until the next Nvidia line up is released sometime this year. It is hard to recommend waiting, though, because we do not know when these will release. They likely will release the most powerful cards first, and the more main stream cards could be a while.

On a side note, I happen to like Victoria 7's skin on Girl 7. I swapped the skins out in my test and downsampled the 2000 x 4000 original image to 1250 x 2500 like the ones above. I also turned off the normal maps, Vicky 7 happens to have a nice toggle built right in her material settings. This time, the render jumped to 64% before I even noticed it, which was right at 3 minutes. Again, the lighting here is just default iray. I suppose I could have tried working the lighting a bit. Of note, I did another render with more makeup, and it took 3.5 minutes to hit 52%, I didn't think the makeup would effect it that much! Perhaps that was an anomaly.

I will try your suggestions. Thank you! I love your renders! Thank for experimenting with the render times. That video card sounds awesome.

novelist999

mjc1016 said:

Something that hasn't been mentioned yet...

Practice...lots of short, quick just a couple of primitives and time to play with all the various light settings. 

novelist999 said:

My son told me that I'd have to either replace the one I have or get another just like it as they can't be mixed and matched.

For Iray, that's not true...they can be mixed.  He's probably thinking in 'gaming' terms or SLI.  Iray shouldn't use SLI so, two different cards can be used together.  A 2 GB 630 would be perfect to pair off with a 4 GB or larger 900 series, for driving the monitors allowing the 'monster' card to be fully devoted to rendering.

I agree--much practice is needed. I feel totally lost in Daz Studio. Yes, he's a gamer and thinks in gaming terms. That sounds promising about the video cards. Thanks for the information. 

novelist999

Havos said:

I am not sure if this has already been suggested, but you will probably get a faster render (and possibly a superior one), using a simple HDR to light your scene, rather than a 3 point light set up. This will likely soften your shadows as well.

This may be slightly controversial, but IMHO a 3 point light set up is largely "yesterdays" lighting solution, no doubt popularised due to that being the default set up for Poser. Using an unbiased renderer like iRay, HDR lighting is superior, and often faster. Try using the one that comes by default with Daz Studio. HDR lighting supplies both ambient light, and (normally but not always), a main light for shadow casting.

I typically use a HDR when lighting up a single character or prop that I will use as a 2D sprite in one of my apps. In most cases this renders in around 5 mins or so, using my GTX 970. Even with a more modest GPU card, you should still get sub-20 min renders of a character like Girl 7.

I'm really confused about the lights in Daz Studio. I'll experiment with the HDR lights and see what happens. Thanks for the tip. 

novelist999

fasttam said:

Put the whole scene inside a cube. Give the cube a light color. Faster render, better soft light

I have no idea how to do that. It sounds interesting though. :-)

mjc1016

novelist999 said:

Havos said:

I am not sure if this has already been suggested, but you will probably get a faster render (and possibly a superior one), using a simple HDR to light your scene, rather than a 3 point light set up. This will likely soften your shadows as well.

This may be slightly controversial, but IMHO a 3 point light set up is largely "yesterdays" lighting solution, no doubt popularised due to that being the default set up for Poser. Using an unbiased renderer like iRay, HDR lighting is superior, and often faster. Try using the one that comes by default with Daz Studio. HDR lighting supplies both ambient light, and (normally but not always), a main light for shadow casting.

I typically use a HDR when lighting up a single character or prop that I will use as a 2D sprite in one of my apps. In most cases this renders in around 5 mins or so, using my GTX 970. Even with a more modest GPU card, you should still get sub-20 min renders of a character like Girl 7.

I'm really confused about the lights in Daz Studio. I'll experiment with the HDR lights and see what happens. Thanks for the tip. 

The link in my sig for the HDRI list has several 'studio' hdrs...these are set up to mimic photostudio lighting, but are hdr images that get plugged into the environment slot, like any other hdr image. 

mtl1

Just to add something very quickly here: specular and glossy materials -- and reflections thereof -- will dramatically increase render times. That is, of course, the price of good looking PB shaders and orders-lower scene tweaking time.

There is an architectural and caustic sampler available in photoreal mode, as well as the interactive mode when rendering under Iray. However, the results for either option were not satisfactory for me but you may get some mileage out of them.

outrider42

novelist999 said:

outrider42 said:

 

I will try your suggestions. Thank you! I love your renders! Thank for experimenting with the render times. That video card sounds awesome.

My card could be grabbed off ebay for about $130 if you look around (maybe less if you are lucky.) It is ok for Daz, but the 2gb memory is very limiting. So you'd be better off getting a new 4gb 960 for just ~$70 more (which would have an added benefit of a 3 year warranty by being new.) I have been able to render images of a single figure as big as 5000 x 2000 pixels with simple hdri backgrounds and lighting in anywhere from 30 minutes to 2 hours. A close up of a face will take much longer. Adding a 3d background also effects it greatly, I can't render a very large 3d background. I think the background that came with the Daz dancer tutorial took me more than an hour at 2000 x 2000. So I usually stick to HDRIs as much as possible, with perhaps a just a few props. I'm still experimenting with the program myself.