From references and modeling to illumination and rendering, Miguel Miranda takes us through the Autodesk Maya and Arnold workflows behind his CG fanart rendition of Disney's Pocahontas.
In this case, the reference was the original Disney version of Pocahontas. The aim was to make a similar model with some creative license.
Starting from a very simple base previously modeled on Maya, ZBrush was used to sculpt the character. From the beginning I wanted to make an approximate fanart of Disney’s Pocahontas but I decided to add my own creative touches that I thought would improve the render: The idea was to make her a bit thinner, enlarge the size of her eyes to gain more expressiveness, thin the neck, and plump the lips.
The first sculpt is usually done in a neutral pose with symmetry, so I did a small test by posing the geometry through the camera.
I made the first render fit the camera (100mm focal length) to the image that I chose as a reference and continued detailing from there. I always kept the object of the lowest sub-tool of ZBrush equal to the one in Maya, so as long as there is no change to the vertices numeration, I'd be able to change from Maya to ZBrush without problems. If vertices numeration is different in ZBrush when you import an *.obj file from Maya, ZBrush projects the details into the new object.
When starting a character it is always important to include a real scale in the 3d program that you use to avoid future problems. In this case, I climbed the Maya sculpt to
167 cm, creating a distance type measure tool. If you have different objects in Maya, you just have to group all of them (the pivot would be in position 0 in coordinates) and scale. Remember that you have to freeze transformations in the objects and then group them once that's complete.
You can also create a cube and give it a Y scale of 167 units, but first, you have to make sure that your version of Maya has the working units in centimeters in the settings preferences.
I did a retopology in Maya using the Make Live tool on the high geometry object brought from ZBrush and the Quad Draw to create the topology of the loops. Once the Make Live is activated, it will create a new vertex on each point you click, and when you have several points with the Shift pressed down and left click between them, you will create a polygon. You also have the ability to create entire rows quickly by holding the shift tight and moving the mouse in the direction that you want and enter whole axes with the control and left click. You can modify the topology roughly: with the vertex mode and the B key pressed (soft selection) you can increase the range of influence by left-clicking and dragging the mouse. If the Make Live is still active you can reposition large volumes to move the topology through the high subdivision sculpt. Finally, you can use a relax tool from the sculpting shelf, to relax the distance between the points of the geometry as you would for any model.
I decided to make the necklace with beads to try something new in Maya. I did it by assigning an object to a curve. First I modeled a collar count with its position across the curve. I used MASH for that: with the selected object I selected "Create MASH Network," and in the attribute editor, in the mash_distribute, you can change the number of duplicates, the distance between them, their scale, and other properties. After that, you select the object and the curve just created, and apply a deformer curve wrap, with which you can touch more values. If you modify the points of the curve, you can place the collar and the objects (created with MASH) so they will follow the curve.
Once finished the retopology I made some UVs with the usual cuts to take advantage of the UV map and avoid stretching.
I made a cut in the neck (to separate the head in the case of making blend shapes for animation) and the back of the neck. The ears were done separately to make sure they'd unfold well on the face. The inner lip was cut to remove it independently. And the usual cuts were done: the trunk in two halves cut by the sides, the extremities, and the hands into two parts.
I wasn’t sure about doing a complete body render, and I recommend to do complete UVs for the whole body to avoid potential problems in the future. I made a quick color base to do some rough renders and to see some results quickly. The sooner the better.
I made the eyes and the crystallines starting with a sphere, with the pupil extruded inside. I placed the teeth in position. I made the texture borders cut in the back for the eyes, so they would not be seen.
The tabs were made with a subdivided plane, I created an alpha channel in Adobe Photoshop and applied it with transparency so the texture could be touched up easily and quickly.
For the hair, I first created a geometric base so that I'd have a basic volume. Then, I converted some of the edges of that geometric base to curves which I modified to give it the shape I wanted. Those curves would be used to assign the hair. Since the problem of the hair was so long, I had to use "Curves/Rebuild" for the segments of each curve into 15 or more to create more points. This way, I could modify the curvature easily.
I started using XGen to gain volume but in the end, as I decided to make a static render, I created an nHair system and adapted the values to what I needed. After that, I assigned the hair system to the curves. You have the nHair menu in the FX menu set. From there, you can create hair and assign the hair system into the selection.
From the attribute editor, I modified the attributes of the hair system as hairs per clump, the sub-segments, the clump, and the scale, allowing me to continue modifying each curve by vertex control. It's an easy way to comb the hairstyle.
The most complicated thing was to give it the shape of the strands since the hair was so long, and also making sure the hair resembled the original design.
TEXTURES AND SHADERS
For the textures, I painted a base colour in ZBrush, then continued in Photoshop. The moment it needed more work was when I was finishing the skin, I wanted to avoid a "whitewashing" texture because Pocahontas has an evidently dark complexion. So after trying several color tones for the texture, I used one that I considered the closest to her skin in the render. I also added some freckles.
I darkened the eye diffuse color, so the character looked closer to the original design, in which the eyes have black irises.
For the skin, I used an aiStandardSurface shader with a hand-painted diffuse map, a specular map, and subsurface scattering. I also used a displacement map on the shading node to add more details.
I added a vector displacement map for some details from ZBrush.
There are several combinations of export settings, but to use Arnold for rendering without problems, the compatibility pipeline was used to export the map with the values in vector Displacement Map in FlipAndSwitch and Tangent FlipAndSwitch. You can find it in the Preferences menu > ImportExport ZBrush. But It depends on the version you have of Maya/Arnold and for that, you have the diagnostic file: It has an option to create diagnostic files based of your export settings in the Tool/Vector Displacement Map sub-palette. These diagnostic files are comprised of an .OBJ file, a diffuse map, and the generated vector displacement map.
For the displacement map to show, I had to go into the main shape tab and add iterations to the Subdivision (Type Catclark) and Maya node setting: file node color space set to raw.
To illuminate the scene, I used an HDRi image applied to an Arnold Ai Skydome Light as my main light. I also added some directional lights for some effects I was looking for, especially the hair rim. I also made small modifications with blendshapes and lattice to the character's pose to give it more appeal on camera and be more natural.
The AA 5 camera was used for rendering. I also made the background with a painted texture simulating the image of the film. I tried it with a bit of fog, but it wasn't quite what I'd expected, so I left it cleaner.