Lighting and Rendering

So far, you've worked through the various types of modelling, UV mapping , and texturing processes. Now, add lighting and rendering to your digital repertoire. Work through this topic to learn how to:

• work with lighting to make your scenes appear more realistic
• create believable environments by simulating natural light sources, shadows, and reflections.

As with the previous  Modelling and Texturing topics, some of the subtopics in this Lighting and Rendering topic are paired with corresponding subtopics outlining integral system steps and videos that you will need for your learning tasks and assessment preparation.

The main subtopics you will explore in Lighting and Rendering include: 

• Introduction to Lighting and Rendering
• Exploring Lighting and Rendering
• Create and Set Up an Image-Based Light
• Light Types
• Recreate a Studio Lighting Setup
• Direct Lighting Workflow
• Light Linking Process

Learning tasks that will support your skills in digital production have been outlined in the following table. 

Before you render a model or shot in Maya, you must go through lighting that shot or model. The lighting process involves creating and setting up lights of various types around your shot or model to enhance the mood or feeling of a shot or model. If done well, your lighting will improve the look of your final scene.

Comparison with physical lighting

You can compare lighting a scene or model in 3D to how a photographer lights a model or how a gaffer lights a film set. Many fundamental concepts are the same from the physical to the digital world, with the added benefit of far more flexibility for the digital lighting artist.

What are the advantages of digital lighting?

The digital lighting artist can create an infinite number of lights. 3D lights can be placed in almost any position in a scene without regard to safety or physical limitations. 3D lights can be linked to particular objects in your scene to only illuminate that object. You can choose whether lights create shadows or not; you can also decide what type of light a light can make, whether specular light only, ambient light only or both. Lights can be any colour in the spectrum or even suck the light out of an area.

Exploring lighting further

Lighting in 3D is a rabbit hole that only gets deeper the more you learn. In this course, you can only scratch the surface of what lighting can accomplish; it will be up to you to dive deeper and further your understanding of the initial concepts discussed.

Indirect Lighting Workflow - Image-based Lighting

Where is image-based lighting used?

Image-based lighting (IBL) is used mainly in Indirect and Physically Based Rendering (PBR) workflows. PBR rendering is used in the games industry to render games in real-time as a player interacts with a game. As rendering lights, textures and materials are so intensive on computer or console hardware there was a need to develop a system to light an environment with as few lights as possible. This is because for each light that is added to a scene or environment, it also adds to the calculation load the renderer must process resulting in longer render times.

What are its application in visual effects?

Another main use for Image-based lighting is the area of visual effects for film and TV, were any computer-generated elements need to match the lighting conditions of a set exactly for them to be seamlessly composited into a shot.

Capturing lighting conditions

To capture the lighting conditions on set at the time of filming, the VFX team will use a chrome and matte grey sphere to capture reference of lighting and reflection conditions and then use a special 360-degree camera to capture a high dynamic range image (HDRI) of the light information on set. Then the reference and HDRI can be used by the production and post-production artists to match lighting conditions on set exactly.

Where can you find IBL resources?

There are manyonline IBL resources. You can download HDRI files from https://polyhaven.com/hdris. All images and assets on polyhaven are free to download and use in your work.

HDRI images are downloaded as an .HDR or .EXR file depending on the program you want to use them in, Maya can recognise either.

There are also several HDR Images that are prepackaged with Maya.

In the following example of an HDRI image the 360-degree image is the HDRI file that will be used as an image-based light source. The rendered spheres below are examples of the lighting, shadows, and reflections this HDRI will produce.

Another benefit of using an image-based light to light a model or shot, is that they are relatively quick and easy to create and set up compared to the standard direct lighting workflow of lighting a shot.

Explore the process of creating and setting up an image-based light in this subtopic. If at any point you need to refer to the steps, select this subtopic in your navigation bar.

How to create and set up an image-based light

Follow the steps below to create and set up an image-based light.

• Go to the Rendering Menu set by choosing 'Rendering' from the pull-down menu at the top of the screen.

This will give you access to the rendering specific menus for Maya.

• Create an Arnold Skydome light by going to: Arnold>Lights>Skydome Light.

A sphere will appear around your scene in the viewport. Currently the Skydome is emitting white light because the colour of the light is set to pure white by default.

To connect an HDRI to the Skydome follow the steps below.

• Go to the attribute editor (Ensure you have the Skydome selected to access its attributes).

Connect a file node to the colour attribute

• Select the checker box button on the right and from the picker.
• Select 'File'.

Using the attribute editor

• Use the folder icon next to the image attribute and navigate to an HDRI file.
• Downloaded HDRI files should be saved in the source images folder of your Maya project filing system.

To render the scene

• Open the render settings window.
• Select the Arnold renderer from the dropdown list.

• Select the render button.

As you are rendering using Arnold, you may find that you need to tweak your Maya materials so that they render as you initially intended. Materials will behave and render differently when rendering with different render engines. Native Maya materials will look far shinier and more reflective than you initially intended when rendering using the Arnold render engine.

After some material tweaks, the following is an example of the spacecraft being lit by only an HDR Image in Arnold.

There are some attributes in the Skydome light that you can use to adjust the look of the render. The main ones that you will want to adjust are:

• Intensity: Controls the brightness of light emitted.
• Exposure: Works like the exposure settings on a camera and multiplies the exposure settings. Positive and negative values can be used to brighten further or darken the render.

The exposure attribute is helpful if you are used to working with cameras and camera equipment. It is also helpful if you are asked by someone who is used to working with cameras “to increase the exposure by 1 stop”. You can then go to the exposure setting and increase the exposure to 1.

If you are not used to exposure, then you can just use the intensity value to control the brightness of a light.

You may also want to adjust the attributes in the Visibility area of the attribute editor. Each of the sliders control a specific type of light that is being emitted by the Skydome Light giving you individual control over each.

Select each of the following headings for more information.

The Skydome itself can be rotated and scaled to adjust the direction of the light source.

Watch the following video (7:30m) on how to set up an image-based light.

Common render settings

With a model textured and the scene lit, it is time to start thinking about rendering your project. You will need to use the the following render settings to adjust and setup before making a final render of your shot.

Common tab

All the render engines in Maya have a Common tab. The common tab contains all the render attributes which are shared from render engine to render engine.

The first area inside common render settings to set is the File Output section.

Here, you can set your file name and file format, determine whether you want to render a single frame or a sequence (any pull-down options with a # will render a frame sequence) and choose the number of digits (frame padding). Maya is to add to the frame numbers if you render a sequence of images.

The following section Frame range can only be set when you have chosen to render a sequence of frames by setting a Frame/Animation ext to one option that includes a # in the name.

In the below example, name#.ext has been selected, which means that rendering a sequence of frames is required, and each frame will be output with the name you set in the section before, e.g., SpaceshipColour, then the frame number, e.g. 001, and lastly the file extension, e.g. .jpg.

With the output set to a sequence and the name set you can now set a start and end frame in the Frame Range section.

The By frame option allows you to skip frames in the sequence. With it set to 1, Maya will render every frame in the sequence from the start frame to the end frame.

If you change the 'By frame' option and set it to 2, for example, Maya will skip every other frame in the sequence and render out frames 1, 3, 5, 7, 9, etc. Set to 3, it will render every third frame, for example, 1, 4, 7, 10, 13, etc.

Most of the time, you will leave this option set to 1 and render every frame of your sequence.

In the Renderable Cameras section you can select which camera you wish to render from.

The above option will render the perspective camera view. If you have created any other cameras in your scene, they will be listed and selectable in the drop-down menu.

The last of the common settings is the Image Size section.

Here, you can set the frame size of the images rendered from Maya. There is a list of preset sizes at the top of the section, which you can select from the pull-down menu, or you can set your size manually by setting a width and height.

Maya Software tab

The first tab in Maya software is literally a quality tab. You can choose the quality settings you want to use for your render from the pull-down menu. The general rule of thumb for quality settings here is that while you are working on a scene, you want to leave the settings on a low-quality setting like the default one you see here. Once you are ready to render a deliverable version of your scene, you would set the quality settings to a higher setting like 'Production Quality', for example.

Note: The higher quality settings will take longer to render than the lower quality settings according to how heavy your current scene is.

Then, you can enable raytracing in the Raytracing Quality area. Raytracing allows Maya to calculate how lights bounce off glossy surfaces, calculate refraction in transparent materials, calculate and render reflections, and calculate raytraced shadows.

With this setting turned off, reflections, refractions, and raytraced shadows will not be displayed in your completed renders.

Turning Raytracing on using the check box will give you access to the quality sliders below. These sliders control the number of steps that maya will calculate each of these attributes. The higher the number pushes the quality levels up and closer to real world conditions and will also result in increased render times.

Select each of the following headings to learn more.

Maya hardware 2.0

The Maya hardware renderer uses your GPU to render the scene. The hardware renderer generally uses this to render any work as it currently has limitations on what the render engine can accomplish, which do not align with the rendering demands of most productions.

At the time of writing the hardware renderer-supported features are:

• File Output settings in the Common tab in the Render Settings window are supported.
• Rendering from different camera types (including stereo cameras) is supported.

Limitations of the Hardware 2.0 renderer

• In the Render View window, the Render region is not supported.
• IPR is not supported.
• Render layers are not supported.

Only colour output is supported. Depth channel is currently not supported.

Arnold Renderer tab

The Arnold Renderer is a high-quality raytracing renderer that can produce high quality and realistic renders.

You can adjust the quality of the render in the main Arnold Renderer tab. To increase or decrease the quality of the render you use the samples sliders which are divided into 6 different categories.

Note: Increase in the number of samples = less noise in the final render.

Each category controls a specific area of the render quality which means that you can tailor your render to each scene that you need to render. If a scene is heavy on one of the areas: for example, if there are characters with realistic skin which has subsurface scattering in its material properties, you can boost the number of samples for SSS (Subsurface Scattering) resulting in less noise and higher quality in the SSS attribute of the skin material calculation.

Select each of the following headings to learn more of each category.

There are a considerable number of settings that you can adjust in the Arnold Renderer tab, but for the most part, you will only need to change the sample sliders and leave the rest of the settings at their default values.

System tab

In the System Tab, you can choose whether to render using the CPU or GPU in the render device pull-down menu.

All the settings below the rendering device drop-down menu control how your system handles how it will render a scene. Generally, leaving these attributes and settings at the default values is recommended.

All the settings below the render device drop-down menu control how your system handles how it will render a scene. Generally, leaving these attributes and settings at the default values is recommended.

AOVs tab

The AOVs (Arbitrary Output Variables) are settings that control how you deliver your render output for post-production. Specifically, how your render is arranged and if it is broken up into passes that go together in compositing to make up the final image.

If you do not need to adjust the render when compositing, you can leave the AOVs and not select any. The render will process usually, and the output will combine all the different passes in a final combined image.

However, do you want or need to adjust a render when compositing? In that case, you can select from the Available AOVs list and add them to the Active AOVs list. This will tell Arnold that the active AOVs should be made available for compositing and not combined during the render process.

AOVs that are common in compositing have been illustrated in the following table.

AOV	Description
A	Alpha
ID	Random number assigned ID pass to identify and isolate materials or objects in the frame.
RGBA	Red, Green, Blue, Alpa pass Containing the full rendered image.
Z	Depth of the shading points as seen from the camera. Used in compositing to add depth blur or environment fog to a shot.
Diffuse_albedio	Diffuse colour without any lighting or shadowing
Diffuse_direct	Direct lighting
Diffuse_indirect	Indirect lighting
Specular_albedio	Specular colour without lighting or shadow
Specular direct	Specular direct lighting
Specular indirect	Specular indirect lighting

Many AOVs can also be selected depending on the requirements of the compositing team.

When rendering Active AOVs, they are stored in layers inside a single.EXR file. You will need a compositing program that supports EXR files to access the layers. Adobe After Effects does support the EXR format and Arnold AOVs.

Diagnostics tab

The Diagnostics tab allows you to tell Arnold how to handle errors and where to save error logs. Error logs can be useful when trouble shooting rendering problems for a scene.

You can choose whether to display errors only in the console or to save them to a file, set the maximum number of warnings to display and what type.

Watch the following playlist made up to two videos dfocussing on render settings.

Render layers

Using render layers gives you more flexibility, allowing you to render out passes as separate files. You can choose the file extension that you want and not be locked into using an .EXR file.

Arnolds AOVs also don't do all the things that you may want to render out of Maya. For example, separating characters into different renders or separating the background into its own render or creating a render with the wireframe of the geometry visible for presentation purposes.

Sometimes you want to render out these things as separate files, in these situations you will need to create what are called render layers. You will need to create a render layer for each of the separate render passes that you want to render.

How to set up render layers

The following steps will guide you through setting up your render layers.

To set up a render layer you need to access the Render Setup Editor:

• To open the Render Setup Editor, use the button at the top of the screen clustered with all the render buttons.
• The button for the Render Setup Editor looks like a clapperboard with two layers in front.

The Render Setup Editor will open and look like the following window. Render layers are added in the area in the bottom left of the window, with attributes and options for the layers appearing on the right side of the window.

• Create a render layer by selecting the Create a Render Layer button.

• This will create a new Render layer in the area on the bottom left.

• Give the Layer a meaningful name, for example Spacecraft_Colour.

The Name should indicate what is going to be included in the layer (in this example, the Spacecraft model) and should also indicate something about the render type, in this case it is the 'Colour' information.

Currently the render layer is empty, so you need to add all the objects that you want to render into your render layer.

To add objects

• Add a collection to the render layer.
• Right mouse click and select Create Collection from the options.

• Give the collection a name.

With the collection selected you will see some options on the right side of the window. This area tells you what is currently included in the collection. Currently the collection is empty.

To add geometry and lights to the collection, follow the steps below.

• Select all the things you would like to add to the collection using the outliner.
• Add them to the collection using the Add button on the right.

The spacecraft and the Skydome light have been added to the collection and will now be rendered as a separate layer. When you render a scene, Maya will create a folder inside the Images folder of the Maya project file system called 'Spacecraft_Colour', the render layer name. All the images for this layer will then be rendered into this folder to keep them separate and organised from any other render layers you may have set up.

If you want to create a special render layer for Ambient occlusion or a wireframe render, you will need to create what is called an override for the collection.

To create an override follow the steps below.

• Right mouse click on the collection
• Select which override you want.

For Ambient occlusion you will use a 'Shader override'.

• Add the aiAmbientOcclusion shader using the right-hand window checker box.
• Search for occlusion in the picker and the shader will appear.

For Wireframe you will use a 'Material override'.

• Add the aiWireframe material using the right-hand window checker box.
• Search for wireframe in the picker and the material will appear.

Watch the following video (10:28m) for the process of setting up render layers.

Cameras

Maya has three main camera types (excluding the two stereo cameras). The first is a standard camera on its own, and the other two both have extra control handles to help align and frame the camera on a subject.

To create a camera in your scene you can find cameras in the create menu.

• Create>Cameras

The standard Maya camera

The standard Maya camera has all the same controls and settings as a physical camera with the added benefits of being able to go beyond the bounds of what a physical camera and camera lenses can achieve.

As animators and artists, the only attributes that you need to concern yourself with when first starting to work with cameras in Maya are:

1. Where is the camera pointed?
2. How should the camera move around your scene?
3. What is in the frame?

Moving the camera

The steps below will guide you through moving the camera.

To move a camera around your scene:

• Select it:
  • Move and rotate it using the standard move (W) and rotate (E) tools.
• You can also select the camera in the outliner:
  • Middle mouse click and drag it into the viewport to switch views.
  • Look though the selected camera.

This then allows you to use the navigation tools:

• Hold the Alt key and use left middle and right mouse buttons to move, tumble and pan the view to move and aim the camera in your scene.

To change what is in frame you can adjust the focal length attribute, essentially changing the amount of zoom on the camera lens.

The focal length attribute simulates the effect of real-world lenses inside Maya. Using a low focal length will give you a wide-angle view out of the camera but will also start to distort the image like a fisheye lens at extreme low ranges (below 10).

A high focal length simulates a telephoto lens (above 70), a high focal length will flatten the field of view which gives the appearance of less depth between objects in the shot.

You can also use the controls drop down menu at the top of the camera attributes section to change the camera into any one of the other three main camera types at any time without the need to delete and create a new camera if you find the camera type is not working for what you need in your shot.

Camera and aim

The camera and aim have all the controls and settings of the standard Maya camera, with the addition of an aim point constrained to the camera's point of view. This is helpful if you have a particular area of a model that you want the camera to be focused on throughout a camera movement.

The aim also allows you to have a static camera position and then move the aim point to simulate the camera panning as a fast-moving object like a car or bike going past the camera position.

Camera, aim and up

The camera, aim and up again, has all the controls and settings of the standard camera with the addition of the aim control of the camera and aim. It also has a new controller that is constrained to the Y axis of the camera, allowing the up-direction of the camera to be animated along with the aim control and the camera's position.

Presentation techniques

When creating work, at some point, you will want to show it either online or in a portfolio or to someone for feedback. You will need to set up and render a single frame to show parts of your work to do any of those things. Or, render a moving sequence for a more dynamic and, in the case of how light interacts with your models and textures, a more accurate representation of your work.

One of the first ways you can create a presentation is to create a shot showing an area of your model or texture work that you want to showcase and then make a slight camera movement over 100 frames or more to either pan, rotate or move in/out on the area being showcased.

Creating slow camera movement to display parts of your model

To create a camera movement, you first need to know how to set keys on the timeline, fortunately that is a very easy thing to do in Maya.

To create a movement, you need to create two keys - these are the starting position and the ending position.

Before you start creating keys it is a good idea to have a clear idea of what you want the movement to look like. The demonstration below will create a slow push on the model.

• First move the camera into a position where you would like the movement to start from.

Remember if you have your resolution gate active you can see where the outer edges of the frame are in the viewport.

Position 1

• With position 1 set you need to tell Maya to save this position as a keyframe.

To save this position as a keyframe:

• Make sure that you are on frame 1 in the timeline.
• The play head in Maya looks like a slightly grey bar which can be harder to see on the timeline.

With the current frame set to 1 in the channel box

• Select all the camera attributes in the translate area,
  • Using the left mouse button and the shift key.

With the attributes selected you can either:

• Right mouse click any of the attributes
  • Then, select Key Selected.

    

  • Or you can use the keyboard shortcut 'S'.

When you have successfully set a key on the timeline a key will appear as a red line and in red in the channel box. Keys can be set for individual attributes independently from each other, so it is a good idea to keep all attributes keyed on the same frame so that your keyframes do not get overly disjointed and confusing on the timeline.

• Next move to the last frame of your camera movement, frame 150 or approximately 6 seconds at 24 frames per second.

• Then move the camera into the second position.

Position 2

In position 2, you will need to set a new keyframe by:

• Selecting the attributes in the channel box
  • Either right mouse click and select Key Selected, or
  • Use the set key shortcut 's' on the keyboard.

For these sort of presentation shots, you will need to keep the camera movement subtle and slow moving so that the audience has a chance to view the model or texture that you would like to showcase. Fast or sudden movement will jar the audience and worst of all make it very difficult to see any of the details of your model or texture work.

Playback your animation to see how it moves.

In the categories area:

• Select 'timeslider' and on the right side of the window in the Playback area.
• Ensure that your playback speed is set to 24 fps x 1.

If you don't like the camera movement, you can delete keys on the timeline by selecting the frame that the keys are on. Right mouse click and choose the delete option.

Turntables

The turntable is another very good way of showcasing your work from all angles. As the name suggests a turntable is a camera movement that spins around your model. In Maya crating a turntable animation is very straightforward.

The following steps guide you through creating a turntable animation.

• First set your beginning position where you would like the turntable to start. You can do this just using the perspective view.
• Next select the object that you would like the turntable to spin around (Maya uses this selected object as the pivot point of the turntable).
• Enable the Animation menu set using the drop-down menu at the top of the screen.

• Visualize>Create Turntable> (optionbox)

The Turntable option will appear. Here you can set the number of frames and the direction of the turntable.

• Select 'Turntable' when you are happy with your settings.

• Maya will create a new turntable camera and group with the set number of frames and movement direction.

Once you have added the turn table, if you play the animation, you will notice an ease-in and ease-out automatically applied to the movement at the beginning and end. This Ease may look good if you only want to play the animation once, but if you'd like to create a loop where the turntable turns multiple times, you must adjust the animation to remove the easing.

To edit the timing of the motion you need to use the Graph Editor. To open the Graph Editor:

• Windows>Animation Editors>Graph Editor.

The Graph Editor will open and with the turntable camera group selected you will be able to see the animation curves for the turntable movement.

When the animation curves for the turntable have been created, the S curve line that goes from the first Key at frame 1, to the second key at frame 300. The curve in-between the two keys represent the movement over time. From the S shape of the curve, you can see that the movement is pushed closer to the beginning and end of the animation which is what gives you the easing of the animation.

To change how the animation goes from frame 1 to frame 300, you need to reshape the curve so that it is a straight line which is what constant speed looks like in the Graph Editor.

To reshape the curve, you will change the weights of the tangent handles for the keys on frame 1 and frame 300.

First select frame 1

Frame 1

When you have selected Frame 1, you will see that there are two very hard to see handles that stick out of each side of the key frame. These are the tangent handles and how you adjust the weighing of the Bezier curve in-between the keys.

Either manipulate the handle manually of you can use the tangent weighting buttons at the top of the window.

You want the one that looks like a straight diagonal line.

This one is for linear tangents.

• Apply linear tangent to both frame 1 and frame 300, your graph editor should now look like this.

Batch Rendering

You will need to send the file to batch render to render an image sequence or animation. The batch render will take the settings from the render settings window and then render each frame of your animation, saving them into the images folder of the Maya project file system.

Before you send your scene to be rendered, it is good practice to have a final check over the render settings for your scene in the render settings window, you would not want to be half way through and realise the render is not correct and need to start over.

Before your render, remember to check:

• frame name
• image format
• frame padding
• start frame
• end frame
• renderable camera
• image size.

Once you are happy with the render settings follow the steps below:

• Select Close to accept the settings.
• Send your scene to Batch Render.
• Enable the rendering menu.
• Set and go to:
  • Render>Batch Render.

Your batch render should now start, and you will start to see feedback about the progress of your render in the command line at the bottom right of the screen.

To see your render happening in real time, open the Script Editor using the Script Editor button in the bottom right of the screen.

The Script Editor view.

The image below illustrates how the Script Editor appears when opened.

Once the render finishes, all the text will stop updating and there will be a rendering completed message at the bottom of the Script Editor screen.

Suppose there are any problems with the render. In that case, a log is generated in the main Maya folder inside 'Documents' on your computer, which may give you more information about the error and help you troubleshoot why the render was unable to start or finish.

Watch the following videos as Geoff demonstrates how to create animated cameras and presentation techniques.

Lighting workflows

Indirect Lighting workflows rely on simulating light coming from a large dome-shaped image-based light or a physical sun and sky simulation and then using calculation to process how light bounces and scatters around a scene and interacts with all the materials and objects. The downside to this approach to lighting is that the artist does not have much control over the overall look or feel of a scene or shot; once you have set up your image-based light, the only absolute control you have is its orientation and intensity. Then the render engine does its magic, and you get what you get.

Direct Lighting workflow is the complete opposite; it uses many individually placed lights to precisely control the lighting and narrative feel of a shot or scene. The lighting artist has infinite control over the look of the shot; the downside to this approach is that crafting the lighting for a shot can take a long time, and the artist places and tweaks individual lights, slowly honing the look of a shot.

Like many other areas of this course, you can only scratch the surface of what is possible in each area. If you find an area enjoyable and wish to delve further into what is possible, you should take the initiative and dig deeper in your own time.

For more information on lighting and lighting workflows, check out the following book:

There are several distinct types of lights in Maya that each create a different lighting effect or simulate a specific type of lighting condition.

All lights share a two common attributes:

1. Colour.
2. Intensity.

Colour attribute

Sets the colour of light that the light emits. The colour attribute can also be connected to a texture or file node to create a textured light with variation. This is handy when you want to create the effect of dappled light as if coming through the canopy of a forest or lights from a TV screen, for example.

Intensity attribute

The intensity of a light is basically how bright a light is. Intensity values vary from light to light, so you must experiment with this value as you create and set up your lights to get the effect you need in your shot. The intensity value can also be set to a negative value, which will result in a light that removes light from the scene; this can be useful to create darker corners of a composition or remove unwanted light from under a bed.

In Maya, there are now two different groups of lights:

1. Maya standard lights
2. Lights that will only work when rendering using the Arnold render engine.

Maya standard lights

Select each of the following headings to learn the six Maya standard lights.

Arnold lights

Select each of the following headings to read descriptions of the five Arnold lights.

Each of Maya’s lights are created to perform different lighting tasks and have individual attributes, which are explored further in the following playlist.

The Light Editor

Maya’s Light Editor has some great organisation and productivity features for the lighting artist. The editor can be opened using the 'Lighting Editor' button found at the top of the screen.

Creating lights

Both standard lights and Arnold lights can be created directly from the lighting editor window using the create lights buttons ate the top left of the editor window.

Grouping lights

Lights can be grouped together by job, or you can group lights by lighting setup.

Using groups and the handy enable/disable and isolate buttons allows for fast and easy switching between lights and different lighting setups. Viewing lights in isolation mode conveniently turns all other lights off at a single click, so you can quickly work on one light at a time.

The look through window

The Look Through window is particularly handy when placing and orienting lights. It opens a separate window that shows the viewpoint of a selected light, this viewpoint can be manipulated in the same way as the Maya viewport for fast and intuitive placement of lights.

Property editor

The Property Editor gives your fast access to a selection of the most used attributes for a selected light source allowing the lighting artist to quickly place and setup lights all from one editor window.

Watch Geoff provide an overview of the Lighting Editor in the following video (5:43m).

Now that you have a basic understanding of the different types of lights and their attributes, it is time to explore and put that knowledge into practice and recreate some studio lighting setups using digital techniques.

As your subject, use these amazing Creative Commons licenced 3D scans of the Alexandre Dumas bust by Jean Baptiste Carpeaux. You can download this and many other 3D scans from www.myminfactory/scantheworld.

Watch the video below (20:57m) where Geoff takes you through simulating studio lighting.

Recreate the 3-point lighting setup demonstrated in the video using the supplied Maya file. Try creating the same effect using the Maya software render engine and the Arnold Render engine.

• Can you create soft shadows using the Maya Software renderer and depth map shadows?
• How do you stop depth map shadows from looking pixelated?

Try recreating different studio lighting setups, such as 2-point or Rembrandt lighting.

• How does changing the light types and colour affect your lighting setups and overall look?

The Digital Camera website has a good cheat sheet for studio lighting setups.

Once you have recreated a few different studio lighting setups, can you create an exciting lighting setup of your own? Try looking at some lighting reference material from any movies by Alfred Hitchcock or the fantastic cinematography of Roger Deakins.

Now that you've covered lighting and rendering, it's time to look at the direct lighting workflow to light an environment.

When lighting an environment using a direct lighting workflow, the number of lights and attributes the lighting artist must track can quickly get out of hand. To help keep lighting scenes organised and straightforward, you need to break downlights and their effect on a shot into several different categories and work on each category one at a time, slowly building up the lighting in the shot.

Select the headings below to view the different lighting effect categories used in lighting workflow.

Not all scenes will need all these categories of light, but it helps when working to work on each category one at a time slowly building up a lighting scheme for the scene. Working in this way helps to keep large, complicated scenes manageable and stops them from becoming too overwhelming.

Generally, when working on lighting a shot, you should follow a structured workflow. The ideal workflow has been outlined in the following step action table.

Step	Action
Step 1	Receive a shot for you to light. The shot may already come with notes on the time of day or night with notes on the narrative of the sequence. If there are no notes, then create some of your own. For example, this is a night shot, everything is quiet, moonlight streams in through a window illuminating the room.
Step 2	Identify and place Keylights in the shot/scene.
Step 3	Identify and place Ambient/Fill lighting in the scene.
Step 4	Identify and place bounce lights.
Step 5	Spend this stage dialling in the lights that are currently placed in the scene. There will be some backwards and forwards here with light settings and placement to refine the lighting.
Step 6	Identify and place Bloom lighting.
Step 7	Identify any areas of the composition that need accenting with more lights to create any: rim lights Highlights extra shadows or darker areas in the composition.
Step 8	Hone the lighting attributes, placement, colouration, intensity etc.
Step 9	cycle through step 7 and 8 several times iteratively crafting the shot making sure to stay within the required composition and shot notes/brief.

Lighting Reference Case Study: TV Room (Night) 3D Render

Now, look at a completed shot and look at the different lights and their placement in crafting the lighting scheme.

Keylights

In the TV room night lighting setup above, there are four main Keylights. Two are area lights, one for the TV and one for simulating moonlight coming through the window. There are also two spotlights for the lamp in the corner of the room.

As all the key lights cast shadows, the TV casts the most obvious shadows. The TV light has an image attached to the colour attribute, so some colour variation is cast into the scene from the TV, as you would expect if a TV was on in the room.

Ambient or fill Lights

There are three fill lights in the lighting setup:

1. One light fill in some light for surfaces facing the front of the room
2. One light fills in light on surfaces to the left of the room.
3. There is a smaller extra fill light that is adding some extra light on the cactus plant on the windowsill.

The cactus fill light has been light linked to the cactus and only affects the cactus models geometry

The images below show examples of ambient or fill lights.

Bleed or Bloom lighting

In this lighting setup, no bright lighting would create the exact conditions required for true bleed or bloom lighting. However, there is a need to create extra lighting around the lamp in the scene. Currently, the lamp only lights up the immediate areas above and below the lampshade, so some added lighting that illuminates the walls and area around the shade is required.

Three area lights have been arranged around the lampshade to cast some much-needed light onto the surrounding surfaces.

A last light has been created inside the lamp to help brighten up the lampshade and make it look more like it is switched on in the shot.

Rim lights and highlights

With some moonlight entering through the window, there is an excellent opportunity to create some rim lighting on the cactus plant on the windowsill, which will help define the plant's edge and help it stand out more from the dark background behind.

An area light placed outside the room facing the cactus plant creates the rim light around the edge of the plant's surface. The light has been light linked to the cactus plant, so it only illuminates the cactus model geometry.

Extra Lights

There is an extra light in this scene that is placed outside the room facing a plane that has an image of a night sky mapped on its surface. This area light illuminates the plane making the night sky visible from inside the room.

All lights combined before any postproduction processing or colour corrections added.

Post-production

In addition to the raw colour pass above, an occlusion pass, and depth pass, of the scene were rendered and then brought into Adobe After Effects for post processing. These have been illustrated in the images below.

The colour occlusion and depth passes were combined in post-production to create the final image. The shot has been colour-corrected to create more contrast in the light-to-dark areas of the scene. The depth pass was used to add depth to the field lens blur.

This subtopic will guide you through the process of creating a light link in Maya. If at any point you need to refer to the steps, select this subtopic in your navigation bar.

In the previous subtopic's case study of the TV room at night, a few lights were linked to specific geometry. Light linking is a feature in Maya that can be great when you add accent lights that only affect one or two areas or objects in a scene. In the TV Room case study, the light linking has been used on the cactus plant as an accent to add a rim and fill light that only affects that geometry, not the window frame or walls surrounding the plant.

Creating a light link in Maya

To create a light link in Maya, you use the Light Linking Editor.

Follow the steps below to guide you through creating a light link in Maya.

• You can find the light linking editor in the Lighting/Shading menu which is part of the Rendering menu set.

You can arrange the Light linking editor to be Light-Centric or Object-Centric. This means if you choose light-centric, the lights will be arranged in the editor's left column, and vice versa if you choose Object-Centric.

If you select a light in the editor, you will see that it is currently linked to everything in the scene as all the objects in the right-hand column are highlighted.

To edit the light only to illuminate the geometry you want to:

• break all the light connections to the light.

To do this, with the light that you want to light link selected, go to:

• the Edit menu on the light side of the editor
• choose 'Make Highlighted Lights Not Illuminate by Default'.

This will break all the connection to that light in the scene and the editor should now look like this with only the light highlighted.

Now that you have broken the connection you can select the geometry that you want to link the light to in the right-hand column.

Now with the light highlighted and the geometry highlighted the new light link has been created and the light will only affect that geometry in the scene.

Light Room

In this basic environment you will practice the workflow detailed in the previous pages. Have a go at lighting the scene first using the Maya Software renderer. Once you have completed your lighting scheme, save your scene as a new version and try to relight the scene using Mayas Arnold Renderer and Maya Arnold lights (you can use standard lights in Arnold too).

• What differences did you find between the two different render engines?
• Was one harder to use than the other?
• Which did you enjoy using the most?

Watch Geoff in the following demonstration videos as he shows the process of lighting this scene using Maya software lights. 

Watch Geoff in the following demonstration videos as he shows the process of lighting this scene using Arnold lights. 

Lighting an environment

For the next learning task activity, you will get to light a premade environment. Light it first as if it is the daytime, then you may choose what time of the day you would like to try and recreate.

Remember to light the scene using the ShotCam as your render view. The Shot cam has already been setup and locked in the project file.

To help you get started there are some good examples of lighting reference at the following link.

Lighting reference https://in.pinterest.com/geoffind/lighting-reference/

Now that you have completed lighting the environment for a daytime scheme. Save your scene as a new version and relight the scene for a nighttime shot. Again, light the scene using the ShotCam view.

Congratulations, you have now finished Lighting and Rendering!  As you wrap up this topic, take a few moments to reflect on all that you have achieved, including the various learning tasks to hone your skills.

You have learnt how to :

• Create and set up image-based lights
• Recreate a studio lighting setup
• Use a light linking process

Learning task #	Learning Task Name	Duration (Hours)
1	Light and render a presentation video of your best piece of work	3
2	Recreate portrait lighting setups	5
3	Light a simple scene	3
4	Light a day scene	6
5	Light a night scene	6

When you're ready, move to the next Digital Production topic, Sculpting.