ways to make Iray Daz renders more realistic?
Drekkan
Posts: 458
in The Commons
I see a lot of good work from Daz Iray users that ONLY use Iray and they look realistic. Athough Iray is generally good I can't seem to get my work looking AS realistic so I wondered if any pro's of Iray's could share their most best method of doing this. Try to keep it simple also please so I can understand.
Remember this is solely using Daz Iray and no other things.
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It might help if you to have/post an example of one or two of your renders you want to improve, and a link to some renders that you are trying to emulate.
In general, it comes down to 1) lighting, 2) shaders/materials, and 3) posing and object placement (things like no feet through the floor, no items floating above the table).
Start off simple, use a top quality HDRI and just one figure (the Luxo Jr HDRI that can be found here is a great one to start with). After you get the materials to meet with what you want, then try the same single figure scene with a three point light rig.This will help you to get used to placing the lights for the desired effect.
Sorry this is so general, but I'm not sure just where you need help. I'm not a great artist, but do most of my renders with virtually no post work. Look through my gallery (links below), and if there is anything there you like, I can tell you how it was set up.
I feel your pain.
I often do a render with only the default environment HDR and it looks perfect in that light. Then I put the character in a room and add lights and it looks awful. I can never set up lighting rigs to match what I see with the HDR but, as most of my renders are indoors, I can't use the HDR.
what exactly is a top quality HDRI please? do you perhaps have an image I could see or an Iray Daz pic you may have created to see how realistic you could get it? thx.
Good shaders make a big difference. Also render settings can make big a difference as well.
If you would post a render or two of your work we could give you some feedback/advice on how to make it look more realistic. :)
Let's start with the Wikipedia definition: High-dynamic-range imaging (HDRI) is a high dynamic range (HDR) technique used in imaging and photography to reproduce a greater dynamic range of luminosity than is possible with standard digital imaging or photographic techniques. A top quality HDRI has a very wide range of luminosity while lesser quality ones are much closer to the range of brightness of a conventional photo. The number of brackets and the range of brackets ensures that you have very bright light in your image, for that reflection in a character's eye or smooth shadows, and nice crisp black values.
...same here.
Skin and Hair are the toughest to get looking right. Many times I get realistic looking backgrounds, props, and settings but the characters often appear as if they are "photoshopped" in as skin looks "rubbery" and hair doesn't have the depth of body it needs because the base textures are transmaps rather than being actual meshes (which would unfortunately increase the polycount dramatically).
I rarely use HDRIs myself as my system doesn't like working in Iray view mode (the only way to see the actual HDRI background for positioning characters and props without having to do a lot of render tests) since I have a an old 1 GB GPU.
You really do need to make sure everything is tweaked as good as you can get it - lights, materials and so on. You can set up everything just right, but you almost can't get away without changing tone mapping settings when rendering: the defaults are not going to give you want you want. You want to play with exposure, fstop and gamma especially. Shutter speed you can usually turn WAY down from the default of 128 to something like 20 to start, fstop at around 16 or 14 to start. Outdoor scenes look better with the exposure between 13-11 generally and indoor between 10-9 generally. Since you can change these while the image is rendering, it's good to experiment with the settings. You can also change film ISO to lighten or darken. Crush blacks will add contrast in the dark areas by turning it up from the default (use small steps since it's sensitive) and burn highlights will dim light areas by making a smaller number (also a sensitive setting). Changing the color of the white point will shift the colors of the image which could make interesting effects. I personally like the gamma set at 1.40 to 1.60, but YMMV. It makes everything darker so you have to change other settings to compensate.
Keep in mind that no matter how careful you are, something is going to give it away as a render....a texture, some modeling..whatever. Postwork may always be necessary ;).
Laurie
Question about tonemapping - is it better to stop the render to change the settings or is it ok to use the sidebar in the render window?
I don't bother with these most of the time but the ones that do that I've seen I think their secrets are dramatic lighting that cast shadows on parts of the face, making characters looking somewhat lightly oily or sweaty, and then postwork in various blur filters.
Also, you'll notice often the best ones often skimp on clothing and/or use dim light with flames or some sort of other distracting light that hides lack of realism with style, because there is a often realism and texture method mismatches between clothing, skin and hair that is very difficult to overcome.
Use the sidebar ;). It will update while it renders :). Most things won't send it back to the beginning, but sometimes it misbehaves ;). If you have a better gfx card you don't really need to worry :).
Laurie
The trick is make sure people are wearing sunglasses, facing away from the camera, or have their eyes closed.
;)
There's that too...lol. Eyes are the biggest giveaway. Hard to get them to look like they have "life" in them ;)
Laurie
The biggest failings I see with DS these days tend to be with gravity... specifically the way the flesh sags and the drape of the clothing forms natural lines. I have a script called Breast Jig that came from Renderosity that helps with the former, for the latter you either have to pose exactly the way the PA intended when they sculpted the outfit, or you have to go to dynamics.
Beyond that, the real secret is postwork. Trying to get everything perfect in the render stage can be painfully slow, but in post you can try dozens of different options in just a few seconds.
I typically do what I call realistic 3D, meaning that everything in the image looks 3D, and not necessarily photo-realistic 3D, which to many means that it looks like a photo of a real person/item. It's a fine line, but I like to think of what I do more of a 3D diorama, that a real life picture. I've added a few images to my post to see if this is similar to what you are striving for. If so, I can do a quick basic tutorial for you to set up and render a single figure and get really good 3D results using the default HDRI that comes with DS, and then the same figure using the Luxo Jr HDRI by Dylan Sisson (http://www.dylansisson.com/project/panoramas/). This should help you understand some of the basics. I do mostly renders of females, so I would probably use Genesis 3 Female in the tutorial, but just to make sure you can follow along, what female figures do you have?
Since you are interested in rendering without post work, in all of the examples posted below (except the second image), the only post work done was using Gimp for a minor adjustment to levels, and adding the signature. The second image was rendered with the default DS HDRI with "Draw Dome" set to off so I could easily add a background in Gimp (Note: you should click on all of the images to view them at full resolution to see the details as I reduced the size a lot for forum display)
The first image below is one of my favorites, and has the best rating of any of the images in my gallery here. It's a bit to complex for a begining render, because it uses several lights, and a lot of shader/material tweaks to get the effect I wanted, but is does give you an idea about the quality of my work so you can judge for yourself if you even want to listen to me
Gallery Posting: http://www.daz3d.com/gallery/#images/84140
This image is an example of a studio setting and was done using the default HDRI provided with DS. Many people don't like this HDRI, but I have found it quite useful, and capable of producing very good lighting and renders.
Gallery Posting: http://www.daz3d.com/gallery/#images/162901
This image is a jungle/forest setting and an example of using a pose to help sell the "idea" (Anticipation is the image title) This was a bit more complex in both lighting and shaders/materials set up, should help you to evaluate my work.
Gallery Posting: http://www.daz3d.com/gallery/#images/137321
This image is another studio type render with a three point light set up (IIRC). It an example of a bit more "dramatic" lighting, and a good example of my idea of realistic3D, since the figure (Girl 7) as a toonish quality.
Gallery Posting: http://www.daz3d.com/gallery/#images/107277
This image is just a fun image that is an example of using the bloom filter in Iray for lighting effects.
Gallery Posting: http://www.daz3d.com/gallery/#images/81595
If your still interested, you van view my other renders here: http://www.daz3d.com/gallery/users/?q=Dustrider&x=0&y=0
As far as I can tell, they work the same. I use the sidebar.
...for character proofs, I use a neutral backdrop prop, a freebie ambient HDRI created by Mec4D (sadly no longer available) and one or two photometric spots set to disc with shadow softness dialled up to between 10 - 15%. This makes it easier to spot issues/flaws with morphs and shaders.
I agree with Nonesuch00 that along with skin and hair, clothing can also make or break the sense of realism. Sadly Daz does not have an "open ended" dynamics engine like Poser, so only clothing specifically created for the Optitiex dynamics system will work within the programme. You can of course use Poser, Marvelous Designer, or any other software allows for "open" cloth dynamics then export character and clothing as a .obj, however that will remove all rigging so you will not be able to make any additional pose or morph adjustments afterwards.
There are also no hair dynamics available either (like Carrara offers) so you are pretty much at the mercy of what movement morphs which may or "may not" be included. If you have and are experienced with LAMH, that will help as the hair can be converted to fibremesh for rendering in Iray (which as a bit more "friendly" render time wise than ,obj format). You would of course need to "pre pose" the hair through styling it as there is no rigging involved.
A tutorial would be awesome :D
With a tip of the hat to the song "The Secret of Life", the secret of a good/great Iray render is : there is no secret.
It takes work and experience. It depends on the type of render and what you want to achieve. It will always be better/easier with good lighting, good shaders, good poses, good details . . . get the picture? Everything matters once you get a basic render. Perhaps the biggest thing is the artist's personal perception. You can see from some the responses here that some folks say they are never happy with skin and hair, while others seem to have no issues with the same.
Personally, I don't struggle with lighting nearly as much as many, but I've been a photographer for over 30 years. My personal struggle is the creative, imaginative composition. Also, my Photoshop creative fu is marginal (but I'm learning).
...yeah my postwork skills, aside from applying filters, adding text, adjusting tone mapping, and using a few "canned" effects are pretty minimal. Don't have a steady enough hand for actual digital painting and never could quite get the hang of layered rendering/compositing to make everything look like it all belonged together.
OK
I'll wait to see if the OP responds with interest in my doing a tutorial or not (my style may not be what he is looking for). If it isn't, I'll stert a new thread with the tut. If it is, I'll do it here.
It's best if you have the same resources I use for the tutorial so you can follow along. I will probaly use V7 if that work for everyone interested, I thought she would probably be the figure that most people have (could use V6 if that would be better). For the rest of the content in the HDRI tutorial, I thought Leyton hair (I would geuss most people would have this as well) and the Dark Storm outfit for G3F. My content is a bit limited for G3F, but if V6 seems to be the figure most people want to use, I have more options for G2F. Since skin settings would be a part of the tutorial, a bikini would also be good - the best bikini I have is Hongyu's Bikini for G2F (never saw a need to get another bikini for G3F), but I'm sure you could substitute any bikini for V7.
It will probably take a few days to put it all together, so hopefully that won't be a problem. The big question is would people prefer it posted as comments in the thread, or as a PDF? I can see advantages to both. As comments in the thread it would allow more interaction as the tut develops, as a PDF (or more likely a couple of PDF's) it would be more self contained and more portable. Right now I'm leaning toward a PDF (that would be easier for me I think), but I'm open to suggestions.
All great observations about what often needs to be tweaked. I personally prefer to get into most of the tweaking in Photoshop, instead of manipulating the settings of the "raw" render too much.
Wait, hold up: there's a sidebar in the render window??
O_O? Can someone explain this to me?
When you have the render window open, there is a very thin bar over on the left that when clicked expands to show Tone mapping and other settings. You can then change these settings while the render is going.
Wow, I can't believe I've never noticed that. O_O
...yeah nice little feature.
Would be great to have such a tutorial. Do what ever you prefer best - a PDF would be great.
It's not exactly outlined in flashing neon or covered in the detailed DAZ Studio manual (sarcasm). One of the many Studio secrets. I found it one day because of an errant click.
has that menu always been there on the render window or just added to the new version?
Been there last two years, at least.
What, doesn't anyone read the documentation? Sheesh!
Ha. A haaaaa.
I think I was told about the sidebar when I asked questions about adjusting the render while in progress - something I was used to doing in Luxrender before I had a card capable of rendering in Iray. Luxrender works completely outside of DAZ Studio (you can even close DS while rendering) so there are a lot more things it allows you to do during the render but the Iray sidebar is a step in the right direction.