The Knowledge behind Making Realistic Portraits

The Knowledge behind
Making Realistic Portraits

So, why faces (portraits)?!...what makes this subject so appealing yet one of the most difficult ones to master as an artist ?!..imho it's because that is the most interesting part in the human body. It is where everything interesting that gives life and character to a person is, and so it gives the same quality of life to the artwork itself. And because "faces" a re the things that we see all around us everywhere and all the time, that's what makes it very difficult to draw or sculpt. You can't cheat with faces, we as human beings are experts when it comes to seeing a face and noticing that it doesn't look natural, even if it was done almost perfectly. But yet again, that's what make this subject very intriguing and interesting to the artist.

"Every portrait that is painted with feeling is a portrait of the artist, not of the sitter."
- Oscar Wilde

Anatomy is your best friend

The first rule to make a successful portrait is to learn anatomy, the second rule to make a successful portrait, is to learn anatomy.
And the best way to start learning the anatomy of the face is not all the muscles, fat and skin we recognise a face by, but it's the skull. Actually having a skull as an armature underneath your portrait while sculpting is what will make it eventually turns out looking natural.
So start by learning the skull, then the muscles, then fat, skin, and trust me when I tell you leave the pores and all the great xyz details for the last 5% of the work.

Resources for anatomy:
- Portraiture and Facial Anatomy for Artists by Scott Eaton. (This course is a treasure, it has everything you need to know about how human faces are built, from skull to fat and skin, and a little bit about FACS and expressions, I study this course at least once every year).
- Anatomy of Facial Expression by Anatomy Next, (best thing about this book is the visuals, you can see clear visuals that explains every part discussed about face structure and muscles.)
- Facial Action Coding System Manual by Paul Ekerman. (The best source to learn FACS and expressions, needles to say this what big VFX companies use as a guide while making faceshapes for characters and creatures in Film.)

Sculpting Likeness

When it comes to Likeness, I think the best way is to study the face you're about to capture the likeness of very well, collect a lot of references from every single angle possible, I use Pureref to make the reference collecting and order so much easier for me (Google it, it's free and awesome), and start collecting reference from front views where the person is looking directly to the camera, then from three quarters views from both sides, then from profile or side views, then top and bottem, etc...
I try to refrain from looking at crazy distorted camera lenses photos. And I always work in Maya with a camera that has a Focal Length that varies Between 75 to 100, an Angle of view that varies between 20 and 25( I use the same Angle of View in Zbrush ).

-Another good tip for likeness, is to check the distances between the furrows on the person's face and his features, and compare that to your reference, for example try to check the distance between the Infraorbital Furrow and the Lower Eyelid Furrow, the distance between the Infraorbital Furrow and the Nasolabial Furrow.
Also the distance between the inner eye corners, and have in mind that the normal is that they should have a
width of a third eye inbetween them.
Look at this photo from the Paul Ekerman FACS Manual that shows the landmarks that you can use to capture the
right ratios to get the likeness of the face you're sculpting.

-Another mistake I see a lot of artists do, and I used to do it a lot, is making the head like a box, with the face sculpted flat on one of this box's sides. Look at the skull from top view, and try to appreciate the roundness happening on all the four corners of the skull, try to depict that in your sculpture.

Resources for Likeness:
- Likeness Sculpting Gumroad by FrankTzeng. (I personally find this tutorial very helpful, and it's where I started learning sculpting Likeness).

- Artists to Study from unfortunately there are not a lot of tutorials and resources when it comes to sculpting likeness. But here's a list of good Likeness artists you can study their work and try to understand how they do it: -Vimal Kerketta.
- Hussein Diba.
- Kris Costa.
- Ian Spriggs, (these are the ones I can remember off the top of my head.)

Sculpting Forms Hierarchy

Think of Sculpting the head, as if you're constructing it from the inside out, from the skull, to the primary forms and the muscles, to the secondary form and the skin folds, to the tertiary forms and the skin pores, and only add micro details to achieve realistic render results (Texturing.xyz maps are great when it comes to that extra 5% that make it look so realistic and belivable.)

You can achieve great results by just having successful Primary and secondary forms and details, but you can't achieve any good results by just having successful tertiary and micro details, while ignoring the primary and secondary.
Look at these portraits by Michelangelo and Bernini, and see how they achieved these natural looking faces by just using primary and secondary forms (no pores!)

Resources for Understanding Forms Hierarchy:
- Of Course start by studying the old masters, like the renaissance masters (Michelangelo, Bernini and Davinci).

- Visualarium Master Class by Kris Costa, (what a valuable resource, Kris goes from skull to primary, secondary, tertiary froms and then pores, excelent way to understand how important forms hierarchy is).

- ANY Tutorial or Video by Steve Lord. The master, when it comes to anatomy and using only primary and secondary forms to sculpt figure and head.

- ANY Tutorial or Video by Jose Perciles. Actually just looking at his work is enough to get you to understand how you can achieve great results using only primary and secondary forms.

Detailing The Skin (Pores!, Yay!)

pores are funL.No one can deny that, but when they are added at the very end of the process of sculpting a head. There's multiple ways to add pores to the skin you're sculpting :

1- Make brush alphas, (or get brush alphas) and sculpt them by hand. (This is the way I like the most, since I have more control over whereto put these pores, especially if you're making a likeness and you want to imitate the pores pattern your subject has).
2- Paint Displacement maps in Mari, using maps from Texturing.xyz. The easiest and most realistic results can be achieved doing that, but you lose the ability to match a person's pores pattern for likeness.
(I use a mixture of method 1 for primary and secondary pores, and method 2 for tertiary and micro pores.)
3- Use your color map to drive the skin details, not the best results, but it works too. (in Zbrush, import your color map, and go to Masking, Mask By Intensity, this will mask the darker spots in your color map, which will be mainly pores and wrinkles).

Resources for Detailing the Skin:

- Texturing.XYZ there is a lot of tutorials on their website on howto use their displacement maps and also the alphas brush set, great resources and great tutorials.
- Realistic Poertraiture with Kris Costa by Zbrush Summit 2018. Watch it for free on youtube.
- Likeness Sculpting Gumroad by FrankTzeng.
- Creating Hyper Realistic Characters in ZBrush by Hossein Di ba.

Texturing The Face

There is also a multiple ways to Texture realistic faces:
1- Using Cross Polarized photos and project them in Mari over your model, (texturing.xyz)
2- Paint color map by hand either in Mari or Substance Painter using a mixture of straight forward painting and procedural painting.
3- Paint color map by hand in zbrush in HD mode.

Resources for Texturing the Face:
- Painting Realistic Skin in Mari by Justin Holt, The Gnomon Workshop.
- Realistic Poertraiture with Kris Costa by Zbrush Summit 2018. Kris shows how he uses the HD mode in Zbrush.
- GDC 2017 Face Texturing in Substance Painter by Magdalena Dadela. Watch it for free on youtube.
- CGMATexturing for Film by Chris Nichols.
- CGMA Head Texturing in Mari by Nicolas Collings.

Skin Shading

I Want to start by saying that I'm not the most technical person when it comes to shading and lookdev, the way I approach shading, is like painting. I look at things in real life, and try to achieve the same results using my shader settings in a very simple and straightforward way.

I cannot recommend enough the importance of reading and studying the Digital Emily project by the USC Institute of Creative Technologies.
They have everything on their website from images, articles and also project files, all for free. So, deifinitely try to grab these project files and try to achieve realistic results using it, and understand how all the maps and the models should look like to achieve such realistic skin look.

I will start by sharing resources to make realistic skin and eyes shaders first, and then share some of my tips and my shader settings.

Resources for Skin and Eye shader:
- Arvid Schneider just watch the videos on this guys youtube channel, it's full of information, and the way I make my shaders is just by basically following his tutorials and Digital emily methods.
- The Digital Emily Project by the USC Institute of Creative Technologies.

TIPS

* Start always by setting up a realistic speculars for the skin before delving into the SSS realms.
Best way to understand the specular light on the human skin is again to look at the Digital Emily Project, usually it is done with two speculars, in Arnold 5 I use the Specular tab and the Coat tab in the AiStandardSurface shader, try to achieve a result that looks like this before moving into color and SSS :

And here's how the settings of my specular and Coat I used for my Mike portrait shader looks like:

*Note that I use an IOR of 1.38 for realistic skin, I use that too for eyes or anything fleshy.
*lf you have good quality displacement map with nice Micro Displacement details, you don't need to make maps for the sepcular and the coat, or even the roughness. It will be enough to use the sliders to only add values.

Skin Shading Tips (Continued)

Next we will look at the Subsurface Scattering part, Take a look at how it looks in my Mike Portrait skin shader here, and then I will explain more :

You see how simple it is ! here's some tips on SSS.

*Try to scale your head model to match real world scale, take a look at this amazing real world measurement
table:


*I always keep the Weight at 1, and use my color map in the Subsurface Color slot.

*Because I was feeling lazy, I used a solid reddish color in my Radius slot, you can always paint a map for this part, and add more variations which will make the skin look more realistic.

*For the Type, I use Randomwalk, it gives me much more realistic results right out of the bat.
Arvid Schneider made a great youtube video about the difference between the Types of Subsurface in Arnold 5, watch it.

*For the eyes shaders, I don't do anything more than just matching the Digital emily eye model setup, and follow Arvid Schneider's video for shading realistic eyes, and useTexturing.xyz color maps for the iris.

Grooming

For Grooming, as I'm not that much of a groomer, I will mention only some of the basics, hat will help you start grooming your characters.
Also I'm only talking about grooming in Xgen, as it's the only software I used for grooming ever.
First let's start by resources, then I will share some basic but important tips.

Resources for Grooming:

- Tarkan Sarim You can find a lot of tutorials on his Patreon page, amazing source to learn grooming in general and xgen specifically.
- Jesus Fernandez he has a patreon page too, and a great youtube channel full of free videos you can start with.
- Beginners Guide To XGen by Michael Cauchi, a great article to start learning about grooming and xgen.

TIPS

* make sure that you're using a maya default material for the mesh you're gonna use for grooming if you're using xgen, for example Lambert, Blinn, etc.., don't use Arnold material for example, it won't work.

* Make sure the mesh name is unique in the scene, written correctly without any spaces, for example: CharacterHead_scalp, Make sure you delete history, freeze transforms, mesh has UVs, all UVs are on first udim on the mesh before applying groom description to it.

* Start with the least amount of guides possible to get the form of the haircut you're after right, and then start gradually adding more guides.

That's it Guys!
I hope this article was helpful, short but sweet, and if you have more questions, leave it in the comments and I will try to answer them.
And again, I will leave you with an inspiring image of a before and after (cause everbody loves those, right!), of how my work used to be three years ago, and how it became once I started Learning from all of these resources.