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3D Artist
Apr
20

24 things you need to know about lighting

Tips & Tutorials
by
Steve Holmes

Industry experts reveal key secrets for achieving better lighting in your 3D work

24 things you need to know about lighting

Research

01 – Observe how light works in the real world How it bounces, how coloured light affects coloured surfaces, and so on. Sometimes it does what you least expect. Jason Scott

02 – Learn to read photographs Get books from great photographers like Jimmy Nelson, Roger Ballen or whoever’s style you fancy and have them laying around your work desk to pick up when you are lost, when your computer is rendering, or whenever you have a spare moment. Then start learning to read the photographs, as there is a lot of information you can get by really studying a picture. Looking at shadows and speculars in a picture can help you figure out what light setup has been used, and what lights serve what purpose. Some lights might serve to separate the subject from the background, while others might serve to attract the viewer’s eye to a specific point in the picture, for example. Kevin Beckers

03 – Get your shaders ready first Don’t rig your lights before you make sure all your shaders are ready – lighting a scene without shaders is a waste of time. Start by using a very simple light – no GI, just simple area light – to see how your shaders will act. Then, when all your shaders become ready, think about more. Mostafa Zaki

04 – Read photography magazines Aside from reading 3D-specific industry magazines, it is also a good idea to read up on other industry publications, like photography titles. They often deal with lighting and composition topics and also have some good tips and tricks on post-production that can help to take your 3D renders to the next level. Kevin Beckers

05 – Don’t be slave to photographic realism You can use photographic references to understand how stuff works, then remember to be creative, you are the artist, you have to bend the light to your needs! Ivan Stalio

24 things you need to know about lighting

Lighting setup

06 – Take the time to set up basic lighting Before starting to set up complex materials and textures, take the time to set up a basic form of your intended lighting setup to get a better idea of how the light will affect the final composition. I will typically only include the basic diffuse, glossy and transparent shaders when testing the lighting. Setting up the basic lighting early on can prevent issues such as having to modify or rearrange models after they are textured and can be a big time-saver. It is also a great opportunity to experiment with new lighting setups that you haven’t tried before, since render times will be quite low. Thomas Cairns

07 – Start with the light that has the smallest effect first Many artists have said this before, but it’s one of the most important things you need to become a good lighting artist. You can’t see the effect of the smallest light if you start with the biggest one. If you test all your lights step by step, then you will not have any problems with a complex setup. Mostafa Zaki

08 – Strip back and get your primary lighting right Sometimes you add so many lights you don’t how each is affecting your scene. Strip back to one, get the angle and intensity where you want it, and start adding extra fill lights back in. Jonathan Ball

09 – Keep experimenting Try different kinds of lights. I usually change my lighting setup every time – I really like to experiment. Ivan Stalio

10 – Use contrast Contrast in lighting will make your scene dramatic and interesting. Try using warm colours against cold ones, or using one huge light source on one side balanced by multiple small lights on the other. Waldemar Bartkowiak

11 – Vary your colours Remember that even while you are using the same light, you can use different colours in your specular channels or maps, simulating different coloured lights and getting original results. Ivan Stalio

12 – Build up a composition Use the lights to build composition of the image. Brighten areas you want to be seen and guide the viewer’s eyes across the image using light rays. To create the moonlight effect in ‘Master of the Books’, I used three lights placed in the same spot, just above the hole in the ceiling, all pointing downwards:

• A Spotlight with a slight blue tint, with five-degree cone angle and intensity at around ten per cent. It’s main purpose was to light the floor and illuminate the main elements in the centre from the top.

• A Large Area Light, bigger than the size of the hole in the ceiling. This light has a dark blue colour and high 180 per cent intensity with the falloff using Inverse Distance Squared setting, which reaches the bottom of the library. It fills the whole room with soft blue light in a gradient pattern. Use of large area light allows me to draw nice, soft shadows.

• The last light is a Distant Light, for the volumetric lighting. It doesn’t affect diffuse or specular, its role is to create a pillar of light, shooting from above the whole scene, through the hole, down to the ground. The intensity of the light is set to 100 per cent, the Effect Dissolve value is set to 20 per cent, and the rest of the settings at default. The radius of the light is roughly the same size as the hole, but really tall, with the length being twice as big as the whole library. This helped me get desired falloff, especially with such an extreme camera angle. I choose pure white, with lots of shades of blue already illuminating the upper parts of the library, it makes the rays stands out more. Waldemar Bartkowiak

24 things you need to know about lighting

Effects & shadows

13 – Setting up your gamma This is very tricky for many artists – physically gamma should be 2.2 but this amount wouldn’t normally give you the result you want. I would use a gamma of 1.6 or 1.8 or 1; remember, you can bend the real physics in your world – it all depends on what you need. Jason Scott

14 – Don’t be afraid of dark areas Not everything has to be lit – dark areas add atmosphere. I often get annoyed when watching films that have scenes set in the dark, caves or unlit rooms, for example, and they have added a low level light so you can see everything. That ruins the entire atmosphere. Jonathan Ball

15 – What you can’t see is as important as what you can Learn to embrace both darkness and shadow. Jason Scott

16 – Remember off-camera lights Imagine a city scene at night, you are rendering a small section of buildings within that city. In reality that scene will be affected by lights from buildings, cars, neon signs and so on that are not visible in the main scene, but are adding subtle secondary light or reflections to it. Add some lights off camera to simulate this. Jonathan Ball

17 – Use volumetric lighting Volumetric lighting, when not overused, can be an easy way to add some extra interest to your scene’s light setup. It is especially useful in interiors and can be combined with obstacles in the light’s path to both add interest to the scene and to focus the viewer on the main subject. Thomas Cairns

18 – Introduce complexity to shadows Whenever it makes sense to do so, try to introduce extra complexity to the shadows of your scene. Even though the environment outside an interior scene may not be modelled, it can add extra interest to the shadows of your scene if alpha-mapped textures such as foliage or raindrops are placed in the path between the light source and interior scene. In Blender I like to use a spot lamp set to a very high strength with a small ‘size’ value to better show off small details from shadows cast by alpha-mapped patterns in front of the light source. Thomas Cairns

19 – Break up the light Breaking up a light, for example by putting a noise map in the projector map in 3ds Max, or placing a ‘tree billboard’ in front of your light, can help break that CG feel you get as the light will have subtle intensity variations, as apposed to this perfect uniform light a CG light gives. Heavy or light dirtmaps in specular or bump slots will also help break said uniformity. Kevin Beckers

20 – Using luminous polygons I like to use luminous polygons – or lumigons – in MODO to create detailed lighting setups. I usually don’t accept my image as complete with just a regular photorealistic light, even if I’m working on an outdoor scene. Sometimes, in addition to the sunlight, I use some more lights because I want to get a shaded area to be more readable, or highlight a particular element or a detail. Ivan Stalio

24 things you need to know about lighting

21 – Add dust particles floating in the air It could be done using particle systems, or simple geometry with alpha planes and works quite well when combined with volumetric lights. Those particles will get picked up by all your light sources, adding a final touch to your render. Waldemar Bartkowiak

22 – Create colour effects In Blender I often create planes with an emission material and a strong colour for my lights. I then use another plane facing an opposite direction with a contrasting colour and a lower setting. This creates interesting colour effects in your scenes. Jonathan Ball

23 – Adding fog Don’t be afraid using volumetric lighting and of adding a bit of fog to your scenes. It will not only add depth to your image, but also it helps build a mysterious atmosphere. You can also add some quick smoke effects by just adding some simple texture in your volumetric lights settings. Good examples of this kind of effect might be light coming through the window blinds in dusty room, or rays cast through a hole in the clouds. Thanks to their interaction with the environment these lights are much more exciting and captivating. Waldemar Bartkowiak

24 – Post processing There is no doubt that post is one of the most important things that any 3D artist should know, but don’t count on it. Use lighting to try to make the best results come directly from your 3D app. Even if you are rendering just passes, make all your passes look beautiful. Don’t wait until you go to post. Mostafa Zaki

Our experts

Jonathan Ball

Waldemar Bartkowiak

Kevin Beckers

Thomas Cairns

Aris Michailidis

Jason Scott

Ivan Stalio

Mostafa Zaki

Images by Ivan Stalio, Mostafa Zaki, Jonathan Ball and Thomas Cairns