Hey guys, I was asked by Autodesk to do a quick tutorial based on the last piece I completed called 'The Blue Project'. For this tutorial I'll be focusing on sculpting skin details in Mudbox as well as creating hair using Shave and a Haircut within Maya. For sculpting I'll detail how I created some of the stencil brushes I used in Mudbox as well as outline some basic tips that helped when creating the surface detail. For the hair portion of this session I'll explain how I created the hair groups and touch a little on lighting and rendering. Thanks for taking the time to read this over and I hope it's somewhat helpful.Brushes - Creating Stencils
Something that will come in handy when creating the skin detail is good stencils. The ones provided in Mudbox do a great job for breaking up the skin but for this specific head mesh I wanted to rely on some photos from the subject I'm sculpting and an image from 3d.sk . I picked these specific photos because they have noticeable poor details that I can use for sculpting.
The way I created the stencils is by taking the individual photos, desaturating them and using the 'High Pass' filter in Photoshop. From here, I played with the levels and brightness/contrast settings to a point where I could distinguish the poor details that would be useful when I bring them in to Mudbox. I tend to go back and forth when creating these in order to get the map to be as efficient as possible. Lets save some out as .tga's and try them out in MudboxSkin - Subdivisions
With our base head model in Mudbox we will need to ensure we have enough subdivisions available for sculpting in fine details. At this stage I have already added the basic facial expression I am wanting and created basic creases and defined the shape of the eyes, mouth and nose. From here I will subdivide it to level 6 in order to start adding the finer details to the mesh on separate layers.Skin - Eyes
I think I'll start by detailing the eyes. First I import the skin stencils I created from photos in Photoshop and pick one that will be suitable for detailing the eyes. Next I create a new layer and call it 'eyes'. I overlay the stencil where details line up with my mesh and use the sculpt brush for painting in the details.
I usually go back and forth between using my created stencils and using basic brushes and stencils provided by Mudbox. You will notice that the details are a bit harsh for a female but when you end up rendering it you will find that much of the details are lost due to the subsurface affect on the skin shader.Skin - Forehead and Cheeks
Time to put in some more poor details. Let's begin with creating a new layer. I cycle back and forth between my created stencils and begin painting in the details for the forehead and cheeks. While I am doing this I use the sculpt brush and create some of the moles, scars and skin blemishes that match the reference of the head I am creating. You could always create these later as a layer but am just deciding to do it now.
Some details look a little harsh but this is what we want. You can see that we have placed the pores in the cheeks, forehead and nose. I also created some additional creases in the eyes and forehead to create some more realistic subtleties. I used the same stencils when I was sculpting the side of the head as well and just used the provided Mudbox stencils to lightly break up the noise a little further.Skin - Mouth
For the mouth area I start by focusing around the mouth before I start the lips. I first create a new layer and I find one of the stencils that will work and start to sculpt. For this area, I ended up going back and forth between Mudbox stencils and my own. For some of the finer poor's I just did them by hand with the sculpt brush and just did some random dots.
I created additional small blemishes, moles and imperfections that help sell the skin a little more. I also added a small scar in the middle of her mouth which is on the subject but you may not notice in the render. Little details like this help in believability for skin surfaces. I can now start to create the lips. I have tried using stencils for this but have never found they work all that well, instead I rely on hand sculpting in all the lines and cracks.
I used multiple Mudbox brushes for creating the lips. The sculpt brush was used for creating the creases and then the bulge was used for thickening the areas surrounding the creases and cracks. If I found that I was not able to get enough sharpness in my creases I used the pinch tool on areas. The lips are time consuming to create and if you don't have enough subdivisions on your head mesh they can look pixilated and blurry.
With my bottom lip complete I noticed that I need some more noise and breakup to make the lips slightly more realistic. Rather than creating a new stencil I just relied on the available ones within Mudbox. I lightly sculpt over top of my creases and break up the surface details a bit just so it doesn't look too clean. One complete I can start the same process for my top lips.
I use the same process for the top part of the lips as I did the bottom. I used several brushes but didn't rely on any stencils other than to break up the surface detail a little. I could have put even more detail in the top part of the lips but I was happy enough with it to call it quits. At this stage I create the minor lines and bumps that transition from the skin of the mouth to the lips before moving onto the neck area.Skin - Neck
The only part left is the chest and neck. As we have in the past start by creating a new sculpt layer. I used a few supplied stencils for surface details including the one shown in the image. I found this worked fairly well with giving the impressions of bumps and overall look of the neck surface. I also created additional moles and bumps by hand just to sell the look a little more.
With the surfaces of the neck and chest complete I start adding the neck lines. I did go fairly harsh with these but only after I test rendered in my scene and noticed that they were not coming through at all with the skin shader. Nothing too special here, just some quick lines created using the knife brush along with the sculpt brush.Skin - Complete
All finished! from here you have a few options on how you want to showcase your sculpt detail in Maya. For this specific project I exported subdivision level 5 straight into Maya and relied on an additional bump map to support the poor detail. The bump map was created by extracting a displacement map of a lower level subdivision mesh of the head (level 4) from my highest subdivision (level 6). It seemed to be pretty successful but you could also use a normal map or an actual displacement map as well. With all our details on separate layer it is easy to increase or decrease the intensity once you start rendering you image. How about we look at some hair now?Hair - Picking a Style
Before we start randomly creating a hairstyle let's look at some reference first at what we want to accomplish. Because I am basing this project off my wife I want to capture the basic look of her hair style. The length, color and way it is styled is quite a bit different from image to image so finding an in-between of all the images will be the goal. I know that I want the hair to part from the side as well for it to be straight and fairly long. With reference gathered let's start creating the hair.Hair - Put a Cap on it.
To start we are going need an object to spawn the hair from. For this I created a hair cap which was from a lower subdivision of our head. I deleted all the unnecessary polys that I didn't want any hair to be present. Once we have our cap complete It's time to create some hair from it.Hair - Create Hair 1.
For this project I used Shave and a Haircut in Maya. To create hair, select your cap and go to the Shave tab at the top and Click Create New Hair. From here you will see some options pop up for deciding what preset to start with. At this point it doesn't matter too much which preset we choose as we will totally change it later on anyways. For now I am going to select blond as the preset.hair - brushing and sculpting the hair
As you can see our hair needs a lot of work so let's use some of the brushes to get a better look to our hairstyle. I notice that the hair is quite short to what I was intending for my hairstyle so to adjust this I first select the guides to the hair (tab at the top) and click on the shave brush. You will notice some options for the brush appear including the grow and decrease length brush. I'll use this brush and start making the hair longer.hair - collision
Before we start styling our hair we will need to ensure we have a collision mesh for our hair. By doing this, when we start to style the hair we won't have to worry about the hair penetrating the head and body geometry. To do this just select the geometry you want to act as your collision and under the Shave menu select edit current - Update Collision Mesh. It may take a few seconds but once it stops thinking test out brushing the hair and notice that it slides along the collision object you've just updated. If you need to undo any brushes, make sure you use the undo function within the shave shelf as using Mayas undo will not work.hair - styling hair - hair settings
There isn't any really quick way of styling hair (that I have found anyways) You need to be fairly patient and take your time with it. I have found that selecting specific guides at one time and using the brush for pushing the hair into place seems to be most effective within Shave and Haircut. At this stage get the hair as close as you can to getting the overall look you want to a point you're unable to tweak too many more settings. As shown, these are the settings I used for my hair that you may find useful. When you find the hair settings you're happy with, save them as a preset so you can grab them later on.
You will notice that I have the hair count high at this point but that is more or less for testing out the density of hairs in the view port. For this next step you will want to decrease it to around 3000 in your settings. When we started styling the hair in Shave and Haircut we were able to get the basic block out of our overall shape somewhat quickly. That being said I have found that working with nurbs curves seems to work the best for giving you more control on how your hair looks (even though its more time consuming). Because of this we are going to convert our hairs to curves. Just select - Shave - edit current - convert - hairs to curves. It may take a moment but you will end up with a set of nurbs curves now.hair - curve it out.
With our new set of nurb curves you can now start better styling your hair. This is time consuming but it gives you the most control over your hair style. Collision will not work anymore of course so be careful how you are styling your hair with the curves. Once you are at a point where you are happy with the look of the curves you've adjusted lets create new hair once more based off the preset we saved earlier (you don't have to though, you are able to once again pick a random preset and adjust) To create the hair, we will once again select our cap we created earlier and using the same steps as before create new hair.hair - comb to curve
Let's put those curves we just adjusted to work now. To comb the hair along the curves just select all your nurbs curves and go to Shave - edit current - comb using curves. You will notice right away that it has taken shape to the curves you have styled. From here, if you need to make any adjustments you can use the nurbs curves as your new guides for adjusting the hair.
After some adjustments we have the base of our hair complete. At this point you can do some quick test renders to see how your hair looks and make any needed adjustments to the shader associated with it. With the first hair part complete we will now focus on the 2nd element of our hair and that is the stray strands that make it believable.hair - strands and strays
For this part we will start by using nurbs curves. For this I just duplicated curves I used for the 1st part of the hair and rotated and adjusted to create random strays. Don't be afraid to go over the top with these it really adds to the believability of the hair style. While your adjusting these take a look at some reference and make sure your matching the style your aiming for. Once you have your hair strands complete, select all the curves and go Shave - Create new hair. This will automatically create the hair along the curves you've just created.
These are the settings I used for the strands. There are a few differences from the first set of hair we created but the most important is the 'Interpolate Guides' box. By having this unchecked, your hair will follow directly along the nurb curve you've created and not try to create additional hairs between other curves. This is the main reason we created two separate hair spawns so we can have separate control over both.
With the hair now complete try some test renders to see how the hair looks. For initial tests you don't really need any lights or any major adjustments to be made to do this. Try some sample renders from different angles and close ups to make sure your hair is holding up ok.hair - lighting
Depending on the goal of your scene your lights can vary. The reason for the my specific lighting setup is to match the lighting I had done separately in VRay for my head and body. Here I use a basic Key light with shadows present, a fill and a rim light behind the head. This is all adjustable but Shave and Haircut uses spot lights for shadows. Once you have your key light ready just select it, then go to Shave - Shadow Attributes - Add to Selected Lights. By doing this Shave and Haircut will now know this is a light specific for hair and if you look in the light attributes you will now have a Shave Shadow tab. Try playing with the settings in order to get the look your after.hair - hair final
here is a test render of how the hair currently looks with the shave global render settings. The bunching at the bottom is something I should fix but overall it matches the style, color and look I am after for my project. The head and body currently have a Shave background material on them so they render with alpha. For the Render Mode I found that using Buffer seemed to give me the best results. All these settings are tweak able but in general I found they worked the best for the project I was trying to complete. After I render out this image, I also rendered out a shadow matte pass by simply checking the 'Shadow Matte' tab. After some adjustments in Photoshop to adjust lighting and contrast I then layer over top of my separately rendered body and the final image comes together! One final note -- watch out for the other section of "The Blue Project" tutorial that's coming up in the next 3D Creative Magazine issue 37 (January 2012)!