UVW Unwrap & Texture Creation
Now that all of the modeling had been finalized, the last stage to complete the 3D representation of my head was Texturing. This is arguably the most significant aspect throughout the production process as a good texture gives the impression of realism and personality.
Before creating the texture for the model, the surface needed to be examined using a "UVW Map" to identify problematic areas that are prone to stretching. Consequently to conduct this test an "Unwrap UVW" modifier was applied, then a black and white checker pattern was then assigned to the head model. In an ideal scenario the checker pattern should be completely uniform over the entire surface, which would be indicated by perfectly sized and spaced squares. However this inevitably is not the case and additional tweaking is required to produce as little stretching as possible.
One immediate issue was the top of the head, where substantial stretching was evident from the deformed rectangular checker pattern.
Stretched Checker Pattern
Fortunately a tool found under the "Edit" parametres of the Unwrap UVW modifier called "Relax" rectified the problem after several applications. The Relax tool basically does as its name suggests, it relaxes the selected faces/vertices by using spacing on edge, faces or centre angles. The tool can therefore be applied a number of times until the desired outcome is achieved, the amount of relaxation applied can also be fine tuned using the Iterations, Amount and Stretch settings.
This process was also used to rectify further areas of stretching especially around the neck, eyes, ears, nose and mouth. Many of these features are comprised of a complex surfaces and therefore the relax tool alone was not sufficient enough. As a result manual adjustment via moving individual vertices was required to flatten out the UVW Map as much as possible.
Top of Head after Relax Tool
Two built in features included in the "Edit Menu" of the UVW Map Modifier also made overlapping faces rapid to identify using the select commands "Select Inverted Faces" and "Select Overlapped Faces". When either of these commands are used faces that are overlapping or inverted are then highlighted bright red to show their position. These sort of faces need to be eradicated before texturing as they can cause noticeable seams/imperfections in the texture which should be one continuous flowing asset. Once any offending faces had been pinpointed a slight vertex adjustment easily resolved any overlapping edges.
Overlapped Faces in Ear Canal
Now that the square checker pattern had been sufficiently adjusted to remove as much evidence of stretching as possible, the next step was to render out the UVW Map for use in Photoshop.
Relaxed Head w/ Checker Pattern
This was achieved by using the "Render UVW Template" command found under the tools menu of the Unwrap UVW modifier. When this tool is used various options are available including the ability to render edges, seams, fills and change display modes. In order to produce a nice clear set of guides only the edges of UVW Map were rendered out as a Bitmap (.BMP) at a resolution of 4096 px by 2048 px. This may seem quite large for the template however using this size will produce nice sharp edges, additionally the photos from which the face textures will be made from are approximately around the same resolution. This will therefore eliminate the need to re-size any texture selections from the face images, which if enlarged or significantly shrunk to fit the UVW Map would introduce apparent blurriness/low resolution.
Head & Ear UVW Template
The rendered UVW Map was then opened in Photoshop in addition to the reference images of the head, from which the texture will be created. The edges on the UVW template were then duplicated as a "layer mask" allowing them to be viewed over the top of the texture to help align the selected features. Certain selections were then made on the front and side images of the head image which were then pasted as separate layers underneath the UVW guide layer. For example the Eye socket area was selected using the "Lasso" tool, Crtl+C then Ctrl+V were used to paste it onto the UVW template file. The selected eye area was then repositioned and transformed accordingly to match the UVW edge guide as closely as possible. This technique was repeated for the entire face until all of the main features were correctly placed on the face texture.
Positioned Facial Features
The Photoshop file was then used as a material within 3DS Max which was applied to the head in order preview the appearance and position of the copied features of the face texture. This was done frequently by making changes and saving the Photoshop file which would then automatically be updated within 3DS Max to show the specified alterations.
Positioned Facial Features Texture Preview
The next step was to merge all the facial features together in order to produce a seamless, flowing head texture with no obvious joins or gaps visible. This was conducted via using the powerful Cloning tools within Photoshop to fill in gaps and join overlapping selections where the skin didn't flow for example. The main tools used were a combination of the "Cloning Stamp, Spot Healing Brush and Patch" tools. The Cloning Stamp tool basically copies a sampled area which can then be painted over gaps in the skin for example. This is a really useful tool ideal for extending/copying parts of an image, however if it is used too much in one area repetition will frequently become visible. Repeating sections of skin for example would deter from the overall level of realism and consequently any occurrence of this sort was eradicated using the Spot Healing Brush and Patch tools. The Spot Healing Brush is similar to the Cloning stamp, however rather than sampling and copying a certain area it blends the selection based on the colour/position of surrounding pixels. This therefore helped to hide any repeating sections of skin for example to create a nice unique and flowing texture. The final tool used was the Patch tool, this basically combines the functions of both the Spot Healing Brush and Cloning Stamp to fill a selected area with a sampled selection which is then blended with the existing pixels. This tool was ideal for adding further detail to areas which had become blurred as a result of considerable cloning.
Gap Between Features BEFORE Cloning
Merged features After Cloning w/ Patch Tool
Once the front and sides of the head had been merged together the last remaining feature to texture was the ears. These again were textured using the same techniques as were used for the face, however due to the shear complexity of the ear additional action was required to provide a realistic outcome. Firstly the ear was copied from the side of head reference image and then pasted into the UVW Template file. Although the UVW Edge guide could be used to roughly position the ear its complex surface made aligning a 2D version extremely difficult. Therefore in order to aid the situation a "Normals Map" was generated using the Render UVW Template tool in 3DS Max. The fill mode was change from "None" to "Normal" which basically draws up the surface of the UVW based on faces's X,Yand Z positions. The outcome is a vibrant colour image which clearly shows the flow of the textured surface. This image was saved and imported into Photoshop on a separate layer for use with the ears. The selected ear texture was then placed above this layer and given a "Layer Mode" of "Multiply" which made it opaque and allowed the normals image map to show through. Having done this the ear texture could then be sufficiently aligned using the "Warp" and "Rotate" transformation tools.
Ear Texture Warp w/ Normal Map Underneath
When the head texture was finished, further detail was introduced by creating both a "Bump Map" and "Specular Map". Firstly the Bump Map was produced by creating a copy of the textured head UVW Map which was de-saturated to make it purely black and white. A "High Pass filter" was then used which creates an embossed/engraved effect of the image. 3DS Max interprets Bump information based on Alpha Channels (Black & White), black being an area which is lowered inwards and white the opposite creating a raised appearance. Based on this fact the resulting image was altered by manually using a soft white brush to add further detail to areas such as moles & freckles, to give them a slightly raised appearance. The final Bump image was then assigned to the head texture material in its "Bump map slot" and given an value of "30". Extra detail to blend the bumped surface with more of an irregular skin surface was accomplished using a "Fractal Noise Map" with a Tiling of "3.0" and Size of "0.101". This was combined with the Bump Map using a "Mix Map" which basically allows two maps to be merged/overlaid using a given "Mix Amount" which in this case was set a value of "75".
Bump Map Creation
Using the previously created image a "Specular Map" was fashioned using a "Levels Adjustment" to increase the contrast between black and white. A Specular Map is interpreted by 3DS Max in a similar way to the Bump Map, however this time the White information will be signified as "Specular Highlights" and the black areas have the opposite effect of low highlights/shine. Again this was modified using a white brush to paint in areas of the skin which are naturally more oily in real-life. Consequently these would be more shiny, such as the forehead, nose, ears, cheeks and chin. Areas such as the eye sockets and lips were given a vast amount of whiteness as these would reflect a large amount of light due to there wetness. Then to create more of realistic appearance a "Gaussian Blur" was applied, which removed any harsh brush strokes leaving a smooth softened effect. The resulting image was then assigned to the "Specular Level" map slot of the head material and given a value of "80".
Specular Level Map Creation /w Gaussian Blur
Bump and Specular Maps Render Preview
Eyes were then produced for the head model using basic Spheres which where converted to "Editable Poly's" and positioned accordingly in the eye sockets. These were then given a quick eye texture using the same method as the head by applying an Unwrap UVW Modifier. The eye texture was then positioned in Photoshop using a rendered UVW Map of the Sphere objects. This was then assigned to a new slot in the "Material Browser" and given a high amount of "Glossiness" and " Specular Level" to simulate a realistic wet appearance. This newly created material was then assigned to the Sphere objects to simulate basic human eyes.
Eye Texture UVW Align
The final task before running out of time to complete this assignment was to add hair to the head model using the "Hair & Fur" modifier. This was achieved by make a selection of Polygons based on the underlying hair line on the texture of the head. The preset of "Semi-Clumpy Brown" was then loaded as a starting point for the Hair & Fur modifier. The "Hair Guides" were then styled using the "Pop", "Comb" and "Hair Brush" tools to make it flow in the correct direction at each point. The hairline was then given a more precise shape using the "Hair Cut" and "Scale" tools. This proved to be rather a frustrating process as the hair is controlled by the orange Hair Guides which are different lengths compared to the actual hair strands that render. Parameters of the hair itself rather than the guides were then changed including "Scale", "Cut Length", "Hair Count", "Hair Segments", "Hair Passes" and "Root Thick". The colour of the hair was also adjusted by changing the "Tip", "Root", "Mutant" and "Specular Tint" Colours in addition to modifying the "Hue Variation" values. All of these settings were continually adjusted before a satisfactory result was acquired. The entire task of creating the hair was evidently aggravating as any changes made to the parameters had to be viewed by re-rendering the hair which was an exceptionally time consuming process.
Hair Guide Styling
Once I was eventually satisfied with the appearance of the hair, I created a Camera in the scene and manoeuvred it to a desired position for a final render of the completed 3D Head.
Final Rendered Head w/ Hair
Over the last five weeks I have learnt a vast amount of knowledge concerning the creation of organic assets such as a human head within 3DS Max. The process of sculpting the head based on hand drawn Topology was particularly rewarding given the fact that in my opinion the final shape of the head is somewhat comparable to the reference images. Therefore overall I am exceptionally pleased with the way the final rendered head came out, even thought some stages of the production were troublesome.
One of the more significant aspects I would fix if time was not an option, would be to improve the glossiness and realism of the eyes by using an "HDR Reflection" to simulate a wet, reflected appearance. Additionally I would spend a vast amount of time to perfect the hair which is an extremely in-depth modifier involving a substantial amount of time to produce realistic results. The final rendered appearance is also heavily dependant on a decent lighting setup as well as appropriately modified parameters.
The model looks awesome mate it looks just like you!
ReplyDeleteThe right up is well detailed well done mate