Rendering: Hardware Vs Software

In maya there are two main types of rendering; software rendering and hardware rendering. We have mainly been using hardware rendering to model our head. Hardware rendering tries to simulate the final output of our model in realtime as closely as possible to our completed version. This, however, is not always a practical approach to visualizing the final product as hardware rendering is what is happening in your viewports (perspective and orthographic). In a complex scene with high resolution geometry it becomes increasingly difficult for your computer to display the scene in your viewports in realtime. Maya must therefore limit the amount of information that it displays in your viewports so when you interact with the scene maya can update it at a reasonable speed, optimally in realtime. It will be beneficial to the workflow if you could see the results of your work smoothly shaded, textured, with reflections and interacting with a full light set, that is, as close as possible to the completed software rendered version. As the technology we use to produce 3D advances the distinction between hardware rendering and software rendering is constantly being challenged. The 3D gaming industry is a fine example of those pioneers that test these definitions by constantly pushing the limitations of realtime rendering, as games become more cinematic and life-like and the definition of hardware rendering versus software rendering becomes less of an issue for the end user with every major new game release.

When software rendering an animation or a file for print you would tend not to work on the computer you're rendering on. This is still a part of the workflow in terms of the fact that it takes time to render from a 3D software renderer and the time that the computer utilizes, even though it requires no further input from you, must be accommodated for as a part of completing the project. The work you have physically done up to this point must reach all the requirements of the final output.
When you have completed your model and are ready to compose your shot consider this

The process of rendering can be broken down into several basic sub-catergories.

• Texturing
• Composition
• Lighting
• Rendering

Texturing

The textures on our head models should be completed by now, the only adjustments that might need to be done in terms of texturing is simple colourizing. The most efficient way to match the colour of a texture for a specific shot is to create a duplicate of the texture and colourize it with the colour balance setting and match colour setting under Adjustments in Photoshop. Colourize your image to match the lighting in your scene. Although your 3D lights will simulate some of the colour from the light source on your model, you might need lights that are not coloured for general illumination. The areas of your model that are light by these lights still need to look like they are being light from the same light source (assuming that's what the intention is). Simple colour changes can also be made to your model in maya through the attribute editor for the file node used to texture the model. These attributes can be found under the Color Balance section. However photoshop still offers a wider range of choices for colour correction of textures and is the more advisable technique.

Composition

By the time you have completed texturing of the model you should have an idea, at least, of what you want the shot to look like in the final output. When creating a composition for your head model consider what the most interesting angle will be. Then think about how to obscure your choice of angle so as not to include the entire head in the shot. What area's could be cropped? A composition that does not disclose every personal aspect of it's subject, but leads the viewer to fill in the gaps; makes a more interesting shot than a shot where the subject is placed in the center of interest and exposed by the artist as if to say "look what i can do". Infact it's generally a better idea to offset your shots from the center. A centrallized shot has probably got far different implications to what you might think. For example a centralized shot of your head model might make it appear comical unintentionally, particularly if you have your model staring straight into the camera. It might be worth your while to make your character look away from the camera. but in doing so coincide the angle at which your character is offsetting your viewers gaze, you don't necessarily want your character to lead your viewer's gaze off the page but rather to a secondary focal point in the composition.

When setting up your camera it's a good idea to have your resolution gate visible. A resolution gate will visually tell you where the extents of your frame are, anything that lies outside your resolution gate will not be rendered. To turn on your perspective camera's resolution gate go to your perspective viewport and click View -> Camera settings -> Resolution Gate.

Lighting

Lighting is something I consider to be one of the most fundemental parts of creating a successful rendering. The topic of lighting can extend far beyond the scope of this exercise so I'll try to simplify the process by isolating key technical points as opposed to the topic of lighting as an aesthetic.
Maya has several different light types which all have different functions. All lights can be found under Create -> Lights
a point light is a light that shines equally in all directions
Point lights can be quite useful for creating general illumination in a scene and tend to render quite fast.

A spotlight is useful to illuminate the focal point of your shot because it can be aimed directly at something. Spotlights are probably the most commonaly used lights in 3D because they render relitively fast and allow a great degree of flexibility.

For the purpose of our exercise we'll mainly be using spot lights to light our scene. the type of light set we'll be using is commonly referred to as three point lighting. This light set is comprised of three light sources a Key light, a Fill light and a Back light. The Key light is used to reveal the most amount of detail in the image. A Fill light will be used to subtly illuminate the areas of the image that would, otherwise, have been in darkness. The Back light will be used to pick up the highlights that will silhouette the model and reveal it's form.
To create a spotlight click -> Create -> Lights -> Spotlight
Select the spotlight, and in your perspective viewport click Panels -> Look Through Selected
Maya allows you to look through your spotlight to modify it's position in 3D space using your tumble, track and dolly camera tools.
Position your light. When you've completed the task click Panels-> Perspective -> Persp to revert to your perspective viewport. Lights can also be transformed using your transform tools (move, rotate and scale). However be warned that scaling a light does not necessarily mean that the area of illumination the light casts increases accordingly to the size of the light icon being scaled in the viewport. For example scaling a point light will have no effect other that making the visual icon in the viewport easier to see, and since a point light casts light equally in all directions rotating it will have no effect on scene illumination either.

To adjust the settings of your light select the light and open it's attribute editor.
In the attribute editor you can change it's colour by clicking on the colour swatch, the intensity setting will determine how bright your light is in conjunction with the color setting. Generally if you have more than one light in a scene it will be worth your while experimenting with lowering this setting to a value below 1, as maya will add intensity values from one light to another in an area where they intersect. Cone angle determines how large an area the light will cover, higher values mean a larger surface area will be covered. Penumbra angle softens the edges of the light and Dropoff will fade the light inside of the cone angle value towards the center of the light.
Shadows can be rendered as ray traced shadows or depth map shadows. Ray tracing is useful if you need a transparent object to cast shadows and by default will produce a crisp edge to your shadow. We will use depth map shadows which render alot faster and produce a fuzzy edge to our shadows.
To turn depth map shadows on select the light you'd like to cast shadows and open it's attribute editor click to expand the shadows section and check use depth map shadows. Not all lights in your scene need to have shadows on. To adjust the blurriness of the edges of your shadow, increase the Dmap Filter Size attribute, increasing this value to anything above 5 will significantly increase the time it takes to render a frame.

Rendering Your Final Image

Once your scene is setup and ready to render click the render globals button to open the render globals dialog box.

• Select maya software as your rendering engine.
• Specify a resolution, if you're not sure what the final resolution is going to be render your image larger than what you think the final output might be as it is always easier to scale down, scaling an image up is not advisable as this will degrade the quality of the image.
• Under the maya software tab, choose production quality.
• Activate your perspective view and click the Render Current Frame button to render the image.
• Save the image from the Render View window click File-> Save as
• Save the image as a Targa or Tiff or some format that will support an alpha channel and a 24bit colour palette.
• Open the image in Photoshop and click select-> load selection choose alpha 1 as your selection and choose ok.
• You can now copy the isolated head image to the clipboard, paste it onto another document and begin tweaking it.

Check out my new animation to see this guy in action :-)