Why is all the hair so bad? Not just Daz. CG in general.
lamoid_5f20d3e469
Posts: 313
Every synthetic human figure I've morphed, posed, and rendered is always having a "bad hair day." I'm not trying to belittle any products here. There are many extremely talented developers who make beautiful human figures. Some are extremely realistic in nearly every aspect -- except for their hair. One look at a CG synthetic human and you can tell it is not a photo of a real person because of the hair on thier head. Either there are clumps of coarse strands or, most frequently, sharp bends that do not occur in nature. What is it about hair that makes it so difficult to model realistically? There must be some software limitations, because if beautiful, realistic hair was possible the talented developers here would make it. More curious than critical. Honestly.
Daz 3D is part of 
Connect
DAZ Productions, Inc.
7533 S Center View Ct #4664
West Jordan, UT 84084
Licensing Agreement | Terms of Service | Privacy Policy | EULA
© 2025 Daz Productions Inc. All Rights Reserved.
Comments
there is just too much of it and it;s too thin
Actually you can get pretty realistic results from some of the hair products here. Like this one for example:
https://www.daz3d.com/gallery/#images/790321/ ; **Note, this image is not my render.
Try increasing the smoothing to get rid of the sharp bends.
It is still hit or miss with hair products. If you're deeply concerned, then you should be more judicious about what you purchase. Look at what other folks are using in their renders, and ask them what the prodocts are.
Hair isn't just whimsy for rendering, its difficult to make, and style. Its also really intense on rendering engines. (This isn't just a daz issue.) So what's in the Daz store is often a trade off between all of the factors for the product. Personally, if you aren't doing a head zoom, then this probably isn't a serious concern.
Lastly, check your materials and lighting, those can easily ruin a good hair job. (Notice that dougj's render doesn't just have nice hair, but it also has 3-4 lights or some sort of HDRI with 3-4 lights on the scene. This makes a masive difference.)
OutOfTouch hair looks pretty real. Check what's available from the last three years.
i agree with the premise that daz character hair often looks not-that-great.
But ornitrix and xgen core hair looks good
Linday also makes some really good hair that looks realistic.
It looks great, the whole render does, even amazing. Although, from the whole render, the hair is the least realistic thing. Beard looks completely real to me.
Whoa! That looks SO GOOD!
Hair and clothes are just way too bendy/flimsy/loose in ways that are hard to recreate with current CGM tech. And with hair you have strand after strand after strand (well, you technically do with clothes as well, but they're packaged together into a unit).
In the marketplaces, hair is something that shows its digital age now.
Thank you all for your comments. I glean from them that the main problem is the number and density of individual, very thin fibers in a real head of hair. It is so large that it requires enormous computational resources to raytrace. Even the best current consumer hardware cannot meet that computational cost. It simply takes too long to do. To make rendering practically possible, workarounds have been devised.
In Daz Studio models, it looks to me like a head of hair is approximated by a set of straps which can be posed individually (by the designer, not necessarily the user). Each strap is [texture, bump, displacement, normals, etc]-mapped. Groups of the straps are assigned photometric shaders that approximate the wavelength-dependent bidirectional reflectance distribution function of individual fibers. These are layered as well to approximate subsurface absorption and scattering. With alpha channels multiple maps can be overlayed on a single strap to produce variations in the colors across the individual strands. Some developers, e.g. OutOfTouch, do that to produce some of the most realistic looking hair -- in the individual straps.
It seems to me that the main problem right now is in the posing and integration of the straps. Posing requires each individual strap to be flexible so that it can curve smoothly along its length; The best current models permit that. Moreover, with appropriate modifications a strap's curvature can be controlled by a physics engine such as dforce. More problematic is the integration of straps into a unified, realistic, whole head of hair. That is much easier to do with short hair. The examples given by dougj and lilweep above demonstrate some excellent results.
In real human hair individual strands can go in different directions and can interleave with each other. A strap-based model can do that with individual straps. But that often results in the appearance of individual hair bundles that are independent. Real hair doesn't usually look like that. (Dreadlocks do. The strap model ought to be great for those.) Clever and creative CG hair designers have found that including a relatively small number of individual strands that can be posed independently of the straps greatly increase the realism. Perhaps alpha-channeled displacement maps could be used like cutout opacity maps to push the visisble parts of straps that lie below the top layer to align with the straps on top?
Appart from visible hair bundles, the biggest and most obvious problem (to my eyes) occurs when straps bend sharply at a point in an unnatural way. I've attached an example image below. I am not sure why that happens. If you know please explain it to me here.
UHF is certainly correct in pointing out that the lighting can make a big difference. I've attached two images below. Both used three-point lighting with area emitters. One has lights front, back, and overhead, the other has standard three-point lighting with the key-light pointed toward the figure's front-right, a softer fill-light front-left and a back-light pointed toward the figure's back-right. There is quite a difference with the front-top-back lighting looking much better (IMHO) that the standard three-point.
I agree with you, Asari, that your hair looks very good. How did you make it?
If I've got any part of this wrong, please let me know. Thanks!
...for the character Merida in Brave, Pixar actually had to develop both the hardware and software to just create that thick wavy mane of hers using multiple layers of strands layers on one another. Of course to render and animate it, they needed a warehouse sized render farm.
well said LMAO
My hair's pretty bad too, so I don't expect too much from 3D hair. #feelsbadman